[Federal Register Volume 66, Number 95 (Wednesday, May 16, 2001)]
[Notices]
[Pages 27196-27211]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-12275]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

[Policy Statement Number ANM-01-03]


Factors To Consider When Reviewing an Applicant's Proposed Human 
Factors Methods of Compliance for Flight Deck Certification

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of policy statement; request for comments.

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SUMMARY: This notice announces a proposed FAA general statement of 
policy that is applicable to the type certification process of 
transport category airplanes. This policy statement provides guidance 
to FAA Certification Teams that will enable them to conduct an 
effective review of an applicant's proposed methods of compliance 
identified in a Human Factors Certification Plan, or the human factors 
components of a general Certification Plan, if one is submitted as part 
of a type certification certificate (TC), supplemental type 
certification certificate (STC), or amended type certificate (ATC) 
application. This policy also is applicable in cases where an applicant 
chooses to identify methods of compliance in other types of documents, 
such as a letter containing the description of changes to production 
configurations. This guidance describes a process to promote early 
discussion and agreement between the FAA and the applicant regarding 
the methods by which the applicant may demonstrate compliance with 
human factors-related regulations during certification projects. This 
notice is to advise the public of FAA policy and give all interested 
persons an opportunity to review and comment on the policy statement.

DATES: Send your comments by June 15, 2001.

ADDRESSES: Address your comments to the individual identified under FOR 
FURTHER INFORMATION CONTACT.

FOR FURTHER INFORMATION CONTACT: Steve Boyd, Federal Aviation 
Administration, Transport Airplane Directorate, Transport Standards 
Staff, Airplane & Flightcrew Interface Branch, ANM-111, 1601 Lind 
Avenue SW., Renton, WA 98055-4056; telephone (425) 227-1138; fax (425) 
227-1320; e-mail: [email protected].

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA invites your comments on this proposed general statement of 
policy. We will accept your comments, data, views, or arguments by 
letter, fax, or e-mail. Send your comments to the person indicated in 
FOR FURTHER INFORMATION CONTACT. Mark your comments, ``Comments to 
Policy Statement ANM-01-03.''
    Use the following format when preparing your comments:
     Organize your comments issue-by-issue.
     For each issue, state what specific change you are 
requesting to the proposed general statement of policy.
     Include justification, reasons, or data for each change 
you are requesting.
    We also welcome comments in support of the proposed policy.
    We will consider all communications received on or before the 
closing date for comments. We may change the proposals contained in 
this notice because of the comments received.

Effect of General Statement of Policy

    The FAA is presenting this information as a set of guidelines 
suitable for use by certain applicants for a type certificate (TC), 
supplemental type certificate (STC), or amended type certificate (ATC). 
However, the general policy stated in this document is not intended to 
establish a binding norm; it does not constitute a new regulation, and 
the FAA would neither apply nor rely on it as a regulation. The FAA 
Aircraft Certification Offices (ACO) that certify transport category 
airplanes and/or the flight deck systems installed on them should 
attempt to follow this policy, when appropriate. However, in 
determining compliance with certification standards, each FAA office 
has the discretion not to apply these guidelines where it determines 
that they are inappropriate. Applicants should expect that the 
certificating officials will consider this information when making 
findings of compliance relevant to new certificate actions.
    As with all advisory material, this general statement of policy 
identifies one means, but not the only means, of compliance.

Background

    Recent aviation safety reports underscore the importance of 
addressing issues related to human performance and flightcrew error in 
system design and certification. Applicants have demonstrated the 
effectiveness of using a ``Human Factors Certification Plan,'' or any 
other certification plan which identifies human factors issues and 
considerations, to communicate to the FAA their proposed approach to 
identifying and resolving human performance issues. The FAA previously 
issued Policy Statement No. ANM-99-2, entitled ``Guidance for Reviewing 
Certification Plans to Address Human Factors for Certification of 
Transport Airplane Flight Decks'' (64 FR 54399, October 6, 1999; and 65 
FR 19958, April 13, 2000). That policy statement provides guidance on 
the recommended content of a Human Factors Certification Plan. A Human 
Factors Certification Plan is not a required document, but may be 
included as part of a certification project if an applicant so chooses. 
Policy Statement No. ANM-99-2 recommended that the plan include a list 
of the ``Methods of Compliance (MOC)'' that the applicant proposes to 
use to show compliance with each applicable regulation.
    The guidance contained in this new policy statement provides 
further recommendations regarding the review of the applicant's 
proposed MOCs. These recommendations can be used as a means by which 
the applicant and the FAA can establish an early and formal written 
agreement on the methods of compliance for regulations that relate to 
human factors and that are applicable to the certification project. 
This will help FAA Certification Teams address the MOCs as early in the 
certification process as possible, thus decreasing the applicant's 
certification cost and schedule risk.
    This new policy statement is one portion of an overall FAA strategy 
for developing policies related to human factors in the certification 
of flight decks on transport category airplanes. Policy development 
will cover the following areas related to showing compliance with 
regulatory requirements associated with human factors:
    1. Information on the recommended content of certification plans. 
(The FAA previously published this information as Policy Statement No. 
ANM-99-2). This policy is intended to improve the timeliness and 
effectiveness of communication between the applicant and the FAA 
concerning the requirements related to human factors.
    2. Information on how to determine the adequacy of an applicant's 
proposed methods of compliance. (This is the information provided in 
this policy statement.) This policy provides further information on the 
methods of

[[Page 27197]]

compliance that may be proposed in certification plans or other 
documents provided by the applicant.
    3. Information on how to determine the adequacy of an applicant's 
proposed human factors test plans intended to support certification. 
(The FAA has not yet developed or published this information.) This 
policy will support the ACO when it determines that test plans related 
to compliance with requirements related to human factors require FAA 
review and concurrencethe ACO determines that it is appropriate for the 
FAA to review and concur with the applicant's test plans relative to 
human factors requirements.
    4. Information on how to reach agreement on design acceptability 
for human factors analyses and tests performed to support 
certification. (The FAA has not yet developed or published this 
information.) This policy will improve the process by which the 
applicant and the FAA jointly agree on how to determine whether the 
design meets the regulatory requirements. This is especially important 
for those requirements that rely on subjective evaluations to determine 
acceptability.
    5. Information on the recommended roles and responsibilities of 
test pilots, human factors specialists, and other technical specialists 
in certification programs, with respect to regulations related to human 
factors. (The FAA has not yet developed or published this information.) 
This policy will clarify how these individuals should work together to 
review and approve the various aspects of the certification project 
that concern human factors.

Objectives of This Policy Statement

    The policy statement is for use by members of FAA Certification 
Teams, which may include the following individuals:
     Aircraft evaluation group inspectors,
     Avionics engineers,
     Certification Team project managers,
     Flight test pilots,
     Flight test engineers,
     Human factors specialists,
     Propulsion engineers, and
     Systems engineers.
    While this policy is focused on providing guidance to these FAA 
Certification Team members, it may be of use to applicants, as well.
    This policy statement addresses the methods by which applicants may 
show compliance with regulations related to flight deck human factors 
during a type certificateion (TC), a supplemental type certificateion 
(STC), or an amended type certificate (ATC) project for transport 
category airplanes. The objective of this policy is to provide 
information for the FAA Certification Team to refer to's reference when 
reviewing the applicant's proposed MOCs. For projects in which a 
certification plan is not submitted, this policy can stillmay be used 
useful in discussions between the applicant and the FAA about how 
applicants may demonstrate compliance with applicable regulations. 
Although the policy provides information to all members of the FAA 
Certification Team, test pilots and human factors specialists will 
normally determine the interpretation of the acceptability of a 
proposed MOC.
    The goal of this policy is to improve the consistency of FAA 
evaluations of applicants' proposed MOCs. Its purpose is not to 
standardize the MOC for any given requirement; rather, it provides 
information about the issues and factors that should be considered when 
evaluating an applicant's proposed MOCs. The specifics of each 
certification project will determine the outcome of those evaluations 
and the acceptability of an applicant's proposed MOCs.
    The FAA recognizes that decisions concerning MOCs for human factors 
issues are complex and context-dependent. Usually, selecting the 
appropriate MOC for a regulation in a specific project will be based on 
an understanding of the human factors issues and the capabilities and 
limitations of the various MOCs with regard to the issues and the 
regulations. However, it may be appropriate to consider other factors 
to ensure that the desired MOCs are reasonable for the specific 
project. These other factors include:
     The complexity of the project.
     The safety implications of the human factors issues.
     The availability and need for test environments 
(simulators, for example).
     The experience base of the applicant.
     The cost and schedule implications of each MOC.
    These factors should be considered as a whole when determining the 
adequacy of the applicant's proposed MOCs, as well as when determining 
the need for alternative MOCs.
    The Certification Team should strive to agree on MOCs that 
effectively show compliance with the regulation in a manner that is 
commensurate with:
     The significance of the human factors safety risks, and
     The complexity of the issues underlying a finding of 
compliance.
    For example, the FAA should not insist on an extensive and costly 
evaluation of a simple design change that has no significant safety 
implications. Conversely, the applicant should not request a quick FAA 
sign-off for a novel, complex design that may have the potential for 
significant safety-related pilot errors.
    This policy statement does not supersede any current or future FAA 
Advisory Circulars that deal with human factors MOCs. Wherever 
possible, this policy statement attempts to provide references to 
relevant existing advisory material. If there are any cases in which 
there is a conflict between existing Advisory Circulars and this policy 
statement, the Advisory Circulars take precedence.
    The FAA recognizes the current effort of several Harmonization 
Working Groups, chartered under the Aviation Rulemaking Advisory 
Committee (ARAC) process, that may develop regulatory or advisory 
material affecting human factors requirements or MOCs. If these Working 
Groups develop or modify regulatory or advisory material relevant to 
human factors issues, the FAA will review this policy statement and 
update it as necessary to maintain consistency.

Application of the General Statement of Policy

    Because this general statement of policy only announces what the 
FAA seeks to establish as policy, the FAA considers it an issue for 
which public comment is appropriate. Therefore, as stated previously, 
we request comments on the following proposed general statement of 
policy. Resolution of any public comments received will determine how 
the policy is applied in the long term for future projects.

General Statement of Policy

Guidance for Reviewing Human Factors Methods of Compliance for 
Flight Deck Certification

    The guidance provided in the following sections is intended to help 
the FAA Certification Team members review the human factors MOCs 
proposed by an applicant during a certification project. Those MOCs may 
be identified in a Certification Plan or other document submitted by an 
applicant. The applicant may wish to provide this information by any 
number of means, such as:
     Part of a Human Factors Certification Plan or overall 
Project Certification plan, if submitted;
     A separate, unique document; or
     A briefing or series of briefings and discussions.
    Regardless of the medium used for providing information, it should 
be

[[Page 27198]]

organized in a way that shows the relationship between the specific 
human factors requirements and the MOCs used for each. The applicant is 
under no obligation to provide the information described in this policy 
statement, except as necessary to demonstrate compliance when 
certification is requested. However, the FAA considers that early 
discussions of the proposed MOCs for human factors requirements is 
beneficial to both the FAA and the applicant, and may significantly 
reduce certification risk. This policy does not imply that applicants 
should be required to provide extensive, written justifications of 
their proposed MOCs. Rather, the information in this policy statement 
should be used by the FAA Certification Team to evaluate the proposed 
MOCs, and to provide common reference points for discussions between 
the applicant and the FAA.

Organization of This Policy Statement

    The information provided in this policy statement covers three 
topics:
    1. General information on methods of compliance for regulations 
related to human factors.
    2. Identification of design-specific human factors issues.
    3. Identification of regulation-specific human factors issues.
    In addition, a list of selected regulations is included in Appendix 
A. This list contains the same regulations as those cited in Policy 
Statement No. ANM-99-2 (referred to previously). However, Appendix A of 
this new policy statement provides a more detailed discussion of MOCs 
for each of the cited regulations. The FAA also plans to provide the 
information in Appendix A of this policy statement on an internet web 
site, where it can become a ``living document'' and can be updated as 
new regulatory material, information, processes, and technology become 
available.

1. Methods of Compliance

    In the Human Factors Certification Plan, overall Certification 
Plan, or other certification project documents, the applicant may 
propose or describe the methods that will be or have been used to 
demonstrate compliance with the relevant human factors regulations. The 
review and discussion of the methods of compliance is an opportunity 
for the FAA and the applicant to work together, early in the 
certification program, to identify potential certification issues 
related to human factors. Policy Statement No. ANM-99-2 provided a 
brief discussion of the MOCs; the section below expands on that 
information by providing more detailed discussions.
    The methods of compliance are not mutually exclusive. The applicant 
may choose to include any one or a combination of these methods of 
compliance. The applicant should describe all methods of compliance to 
be used in a certification project in enough detail to give the FAA 
Certification Team confidence that the results of the chosen methods 
will provide the information necessary for finding compliance. 
Following is a list of MOCs relevant to compliance with human factors 
regulations:
    1.a. Drawings: These are layout drawings and/or engineering 
drawings that show the geometric arrangement of hardware or display 
graphics. Drawings typically are used when demonstration of compliance 
can easily be reduced to simple geometry, arrangement, or the presence 
of a given feature, on a technical drawing.
    1.b. Configuration description: This is a description of the 
layout, general arrangement, direction of movement, etc., of the 
regulated item, or a reference to similar documentation. For example, 
such a description could be used to show the relative locations of 
flight instruments, groupings of control functions, allocation of color 
codes to displays and alerts, etc. Configuration descriptions are 
generally less formalized than engineering drawings, and are developed 
in order to point out the features of the design that are supportive of 
a finding of compliance. Configuration descriptions may illustrate how 
a design philosophy or concept is implemented in a consistent, easy-to-
understand manner. In some cases, such configuration descriptions may 
provide sufficient information for a finding of compliance with a 
specific requirement; however, more often, configuration descriptions 
provide important background information requiring demonstrations, 
tests, or other means to confirm compliance. The background information 
provided by configuration descriptions, however, may significantly 
reduce the complexity and/or risk associated with the demonstrations or 
tests.
    1.c. Statement of similarity: This is a description of the system 
to be approved and a description of a previously-approved system. The 
description details the physical, logical, and operational similarities 
of the two systems in complying with the regulations. Past 
certification precedents are important; however, this method of 
compliance must be used with care because the flight deck should be 
evaluated as a whole, rather than merely as a set of individual 
functions or systems. For example, two functions that have been 
previously approved on two different programs may be incompatible when 
combined on a single flight deck. Also, changing one feature in a 
flight deck may necessitate corresponding changes in other features, in 
order to maintain consistency and prevent confusion.
    1.d. Evaluations, assessments, and analyses: These are conducted by 
the applicant or others (not the FAA or a designee), who then provide a 
report of their results to the FAA. Traditionally, these types of 
activities have been used as part of the design process without formal 
certification credit. However, when properly performed, these 
activities can result in better designs that are more likely to be 
compliant with applicable regulations. In cases where human subjects 
(pilots, for example) are used to gather data (subjective or 
objective), the applicant should fully document the selection of 
participants, what data will be collected, and how it will be 
collected. This will allow the FAA Certification Team to determine the 
extent to which the evaluations, assessments, and analyses provide 
valid and relevant information with respect to finding compliance with 
the regulations. For a more detailed discussion of how these 
evaluations, assessments, and analyses can be used and formalized, see 
Appendix D of this policy statement.
    1.d.(1) Engineering evaluations or analyses--These assessments can 
involve a number of techniques, including:
     Procedure evaluations (complexity, number of steps, 
nomenclature, etc.);
     Reach or strength analysis via computer modeling;
     Time-line analysis for assessing task demands and 
workload; or
     Other methods, depending on the issue being considered.
    Certification Teams should carefully consider the validity of 
assessment techniques for analyses that are not based on advisory 
material or accepted industry standard methods, and request that 
applicants validate any computation tools used in such analyses. If 
analysis involves comparing measured characteristics to recommendations 
derived from pre-existing research (internal or public domain), the 
applicant may be asked to validate the use of the data derived from the 
research.
    1.d.(2) Mock-up evaluations--These are evaluations using mock-ups 
of the flight deck and/or components. Mock-ups are typically used for 
assessment of reach and clearance and, therefore, they

[[Page 27199]]

demand a high degree of geometric accuracy. Mock-ups have traditionally 
been physical representations of the design, which have allowed 
evaluators to physically interact with the design. In some cases, 
drawings of controls and indicators, placed on accurately positioned 
representations of instrument panels, can be beneficial in conducting 
reach assessments. Using data extracted from computer-aided design 
(CAD) systems, control panels can now be mocked-up physically in three-
dimensional form (a process generally referred to as ``stereo 
lithography''). These mock-ups can allow more precise evaluations of 
finger clearances, visibility of labels, etc. Three-dimensional 
representations of the design in a CAD system, in conjunction with 
three-dimensional models of the flight deck occupants, also have been 
used as ``virtual'' mock-ups for certain limited types of evaluations. 
For example, reach assessments using this technique can use either:
     Statistical samples of relevant body characteristics (for 
example, limb sizes, joint limits, etc.) or
     Carefully chosen sets of specific combinations of body 
characteristics.
    In the latter case, attention should be given to selecting 
reasonable worst-case combinations of characteristics (for example, a 
worst-case might be a 5'2" pilot with more than proportionally short 
legs). Care must be taken to determine if the model of the human 
reasonably represents actual human movement capabilities, especially at 
extreme body positions or near joint rotation limits. It is important 
to note that this type of virtual mock-up and, in fact, many types of 
mock-ups may be of even greater use during the design phase as part of 
engineering evaluations. They should only be used judiciously as an MOC 
because they typically represent only certain features of the physical 
arrangement. For example, a control may be reachable in a given 
location, but, due to the means of actuation or forces required, it may 
be too difficult to use when placed there. For many of the compliance 
issues typically evaluated in mock-ups, final compliance findings often 
can be found only in the actual airplane or a simulator.
    1.d.(3) Part-task evaluations--These are evaluations using devices 
that emulate the crew interfaces for a single system or a related group 
of systems, using flight hardware, simulated systems, or combinations 
of these. Typically, these evaluations are limited by the extent to 
which acceptability may be affected by other flight deck tasks. This 
MOC is most easily used for stand-alone systems. As flight deck systems 
become more integrated, part-task evaluations may become less useful as 
an MOC, even although their utility as engineering tools may increase. 
A typical example of a part-task demonstrator for an integrated system 
would be an avionics suite installed in a mock-up of a flight deck, 
with the main displays and autopilot controllers included. Such a tool 
may be valuable during development and for providing system 
familiarization to the authorities. However, in a highly integrated 
architecture, it may be difficult or impossible to assess how well the 
avionics system will fit into the overall flight deck without more 
complete simulation or use of the actual airplane.
    1.d.(4) Simulator evaluations--These are evaluations using devices 
that present an integrated emulation (using flight hardware, simulated 
systems, or combinations of these) of the flight deck and the 
operational environment. They can also be ``flown'' with response 
characteristics that replicate, to some extent, the responses of the 
airplane. Typically, these evaluations are limited by the extent to 
which the simulation is a realistic, high fidelity representation of 
the airplane, the flight deck, the external environment, and crew 
operations. It should be noted that not all aspects of the simulation 
must have a high level of fidelity for any given compliance issue. 
Rather, fidelity requirements should be evaluated in view of the issue 
being evaluated. For additional information, see section 4.b.(1) of FAA 
Advisory Circular (AC) 25-11, ``Transport Category Airplane Electronic 
Display Systems,'' dated July 16, 1987.
    1.d.(5) In-flight evaluations--These are evaluations using the 
actual airplane. light test generally offer the most realistic and 
comprehensive environment for evaluating the flight crew interface 
design in realistic scenarios. Assuming that the airplane is fully 
configured, the integration of the flight crew interface features can 
be evaluated in a flight environment, including communication tasks and 
interaction with the ATC environment. However, Ttypically, these 
evaluations are may be limited by the extent to which the critical 
flight conditions (for example, weather, failures, or unusual 
attitudes) can be located or generated, and then safely evaluated in 
flight. While evaluations using the actual airplane are the closest to 
real operations, in some cases not all of the scenarios of interest can 
be demonstrated. The applicant may not be able to show certain failures 
or combinations of failures for a variety of technical or safety 
reasons. In such cases, applicants may find it necessary to combine 
flight testing with other MOCs in order to gain a complete evaluation. 
For additional information, see FAA AC 25-11, section 4.b.(1).
    1.e. Demonstrations: These are similar to evaluations (as described 
above), but conducted by the applicant with participation by the FAA or 
its designee. The applicant may provide a report or summary, requesting 
FAA concurrence on the findings. In each case, the applicant should 
note the limitations of the demonstration and how those limitations 
relate to the compliance issues being considered. The FAA should 
carefully consider which of its specialists will participate (for 
example, pilots, human factors specialists, or systems engineers), what 
data will be collected (objective and/or subjective), and how the data 
will be collected. This is to ensure that the demonstration adequately 
addresses the compliance issues and that there is participation by the 
appropriate FAA evaluators. Examples of demonstrations include:
     Mock-up demonstrations.
     Part-task demonstration.
     Simulator demonstration.
    1.f. Inspection: This is a review of a regulated item by the FAA or 
its designee, who will be making the compliance finding. This MOC is 
generally limited to those items for which compliance can be found 
simply by looking at (or listening to) the feature being considered 
(for example, the presence or absence of a placard, the direction of 
control movement, etc.).
    1.g. Tests: These are tests conducted by the FAA or a designee. 
Types of tests include:
    1.g.(1) Bench tests--These are tests of components in a laboratory 
environment. This type of testing is usually confined to showing that 
the components perform as designed. Typical bench testing may include 
measuring physical characteristics (forces, luminance, or format, for 
example) or logical/dynamic responses to inputs, either from the user 
or from other systems (real or simulated). For most human factors 
evaluations, bench tests are insufficient to show compliance, but can 
provide useful supporting data in combination with other methods. For 
example, visibility of a display under the brightest of the expected 
lighting conditions might be shown with a bench test, provided there is 
supporting analysis to define the expected lighting conditions. This 
might include a geometric analysis to show the potential directions 
from which the sun could shine on the display, along with

[[Page 27200]]

calculations of expected viewing angles. These conditions might then be 
replicated in the laboratory.
    1.g.(2) Ground tests--These are tests conducted in the actual 
airplane, while the airplane is on the ground and stationary. In some 
cases, specialized test equipment may be used to allow the airplane 
systems to behave as if the airplane were airborne. Certain failures 
that would be unsafe to test in flight might be evaluated using ground 
tests, provided that the test capability can adequately simulate the 
in-flight failure condition. Another example of a typical ground test 
is an evaluation of potential reflections in displays. Such a test 
usually involves covering the flight deck windows to simulate darkness 
and setting the flight deck lighting to desired levels. This particular 
test may not be possible in a simulator, due to differences in the 
light sources, display hardware, and/or window construction.
    1.g.(3) Simulator tests--[See Simulator evaluations, paragraph 
1.d.(4), above.]
    1.g.(4) Flight tests--These are tests conducted in the actual 
airplane during flight. [See In-flight evaluations, paragraph 1.d.(5), 
above.] In some cases, applicants and the FAA may place too much 
emphasis on flight testing, to the exclusion of other MOCs. This may be 
based on the belief that flight testing is the best available method 
for evaluating the flight deck. While it is true that flight testing 
can be very powerful, it also has limitations. As described in the 
section on in-flight evaluations, above, it may not be possible to test 
all of the important scenarios or conditions. Flight testing provides 
the least control over conditions of any of the MOCs. In addition, 
flight testing is extremely expensive and may not allow a thorough, 
comprehensive evaluation with sufficient numbers of FAA evaluators. 
While many simple evaluations can and should be handled by a single FAA 
evaluator, in other cases, the issues are too complex and subjective to 
be decided by a single person on a few flights, especially for novel 
designs. For such issues, it is often best to use flight testing as a 
final confirmation of data collected using other MOCs, including 
analyses and evaluations. The FAA and the applicant should discuss 
thoroughly how and when flight tests will be used to show compliance, 
as well as how flight test results will be supported by other MOCs.
    1.h. Compliance vs. design optimization: The FAA personnel who are 
evaluating proposed methods of compliance for rules related to human 
factors should keep in mind there may be a number of crew interface 
design features that are compliant with the applicable rules, but could 
be improved. However, applicants are under no legal obligation to 
conduct assessments to show that a compliant design is the best that 
they could implement among feasible alternatives (i.e., is 
``optimized'').

2. Identification of Design-Specific Human Factors Issues

    The MOCs identified above cover a wide spectrum, from documents 
that simply describe the product, to partial approximations of the 
system(s), to methods that replicate the actual airplane and its 
operation with great accuracy. Features of the product being certified 
and the types of human factors issues to be evaluated are key 
considerations when selecting which method is to be used. The 
characteristics described below can be used to help in coming to 
agreement on what constitutes the minimum acceptable method(s) of 
compliance for any individual requirement. When a product may need to 
meet multiple requirements, some requirements may demand more complex 
testing, while others can be handled using simple descriptive measures. 
It is important to note that the following characteristics are only 
general principles. They are intended to form the basis for discussions 
regarding acceptable methods of compliance for a specific product with 
regard to a requirement.
    2.a. Degree of integration/independence: If the product to be 
evaluated for compliance is a stand-alone piece of equipment that does 
not interact with other aspects of the crew interface, less integrated 
methods of compliance may be acceptable. However, if the product is a 
complete flight deck (as in a TC program) or is a single system that is 
tightly tied to other systems in the flight deck, either directly or by 
the ways that flightcrews use them, it may be necessary to use methods 
that allow the testing of those interactions.
    2.b. Novelty/past experience: If the technology is mature and well-
understood, less rigorous methods may be appropriate. More rigorous 
methods may be called for if the technology is:
     New,
     Used in some new application,
     New for the particular applicant, or
     Unfamiliar to the certification personnel.
    2.c. Complexity/Level of automation: More complex and automated 
systems typically require test methods that will reveal how that 
complexity will manifest itself to the pilot, in normal and backup or 
reversionary modes of operation.
    2.d. Criticality: Highly critical systems may require testing in 
the most realistic environments (high quality simulation or flight 
test), because any problems are more likely to have serious 
consequences.
    2.e. Dynamics: If the control and display features of the product 
are highly dynamic, the compliance methods should be capable of 
replicating those dynamic conditions.
    2.g. Subjectivity of acceptance criteria: If a requirement has 
specific, objectively measurable criteria, the applicant can often use 
simpler methods to demonstrate compliance. As the acceptance criteria 
become more subjective, the applicant will need to use more integrated 
test methods, so that the evaluations take into account the aspects of 
the integrated flight deck that may affect those evaluations.
    The central point is to carefully match the method to the product 
and the underlying human factors issues. It is also important for the 
FAA Certification Team to recognize that several alternative methods 
may be acceptable.

3. Identification of Regulation-Specific Human Factors Issues

    The following steps outline a strategy for identifying the human 
factors issues associated with each regulation. Two examples are 
carried through each issue for purposes of illustration. Further detail 
on a selected set of regulations related to human factors can be found 
in Appendix A of this policy statement.
    3.a. Identify key human factors issues related to the rule. While 
rules may focus on a single concept, there may be several underlying 
components that must be considered in order to evaluate that issue.
     Example 1: Section 25.777 (in part) states that the flight 
deck must accommodate pilots from 5'2" to 6'3" in height. This means 
that pilots within this range should be able to reach all required 
controls, see all of the displays, and have sufficient clearance with 
the structure, panels, etc. Height is not the only variable of 
interest, because people of the same height may have different lengths 
of arms, legs, etc. So, consideration must be given to various 
representative body proportions that fall within the height range 
identified in the regulation.
     Example 2: Section 25.773(a)(2) states that there should 
be no objectionable reflections in the flight deck. Underlying 
variables may include the size, brightness, color, dynamics, and 
location of the reflections.

[[Page 27201]]

    3.b. Identify systems, components, and features that are 
potentially affected by the rule.
     Example 1: Components that are near the expected reach 
boundaries, as well as those that may be blocked by intervening objects 
(such as a control that is installed in front of the throttles), should 
be evaluated for reach. Potential knee contact with the lower edge of 
the main instrument panel may need to be evaluated for clearance, 
especially for tall pilots with long legs.
     Example 2: Windows, displays, and light sources (all in 
the correct geometry) may be affected.
    3.c. Look for aspects of those systems, components, and features 
that need to be evaluated in order to show compliance with the rule 
(for example, forces required, readability of labels, and number of 
discrete actions required). These aspects are likely to vary by system, 
component, and feature, and by rule.
     Example 1: Seat and rudder pedal adjustment ranges should 
be factored into evaluations of reach and clearance.
     Example 2: Light source luminance levels, reflectance of 
display surfaces, and readability of the display in the presence of the 
reflections should all be considered.
    3.d. For modifications to existing flight decks or new type designs 
that are based on or derived from an existing flight deck design, look 
for ways in which new aspects of the design may compromise compliance 
with previously certified designs.
     Example 1: Reaching for a new control may result in the 
inadvertent activation of a previously installed and certificated 
control. Another example might be the possibility of striking one's 
head on a newly installed head-up display when reaching for an existing 
control on the main instrument panel.
     Example 2: Placing a new display device in the flight deck 
may produce new reflections in the windows. In another situation, a new 
electronic display [for example, a liquid crystal display (LCD)] may be 
more susceptible to reflections than the electro-mechanical display it 
replaces.
    3.e. Review past precedents. In this context, precedents should be 
reviewed to assess novelty of the design, because novelty of the design 
will often affect the selection of an appropriate MOC. Similarity to a 
previously certificated design does not necessarily mean that the new 
product will be certificated. Rather, that similarity may result in 
fewer unknowns and a commensurate reduction in the rigor of the 
evaluations. It is important to assess whether or not there are new 
issues or interactions that were not present in previously certificated 
installations. Because it is the installation (in the flight deck) that 
is certificated, not the equipment itself, it is important to look for 
installation-unique issues when evaluating the relevance of past 
precedents.
     Example 1: Two questions to ask are: If a new control is 
being added, have other similar controls been installed in the same 
location on other versions of this flight deck? Are there any other 
differences that might cause new reach or clearance issues to emerge?
     Example 2: Determine whether the actual LCD ``glass'' in 
the new device is already certificated in similar installations. If so, 
there may be less concern about unacceptable reflectance 
characteristics. However, any unique characteristics of the lighting 
environment in the new installation may increase uncertainty.
    3.f. Assess design novelty. In addition to the need to fully 
determine their compliance with existing rules, novel designs may 
require more rigorous evaluations to ensure that their novel features 
(not covered by current regulations) do not result in any new safety 
problems. Note: Any evaluations intended to identify such new safety 
problems, which might require the development of Special Conditions, 
should be accomplished as early in the project as possible. This will 
allow the FAA and the applicant to reach a common understanding of the 
issues, and to allow the applicant sufficient time to show compliance 
with any resultant Special Conditions.
    3.g. Review the proposed MOCs for each human factors rule and 
determine if, taken together, they adequately address the compliance 
issues that have been identified for the relevant systems. There is no 
formula for this determination; it is based on the judgment of the FAA 
Certification Team. It is important to note that this step is not 
intended to determine if all potential human factors issues have been 
fully addressed. Instead, it is concerned only with determining if the 
proposed MOCs address the regulatory compliance issues, including those 
associated with Special Conditions.
    3.h. If the proposed MOCs do not fully address the human factors 
issues associated with compliance, determine if the level of effort 
needed for the MOC preferred by the FAA Certification Team is 
commensurate with the level of safety risk and the compliance 
uncertainty. This step is also based on the judgment of the FAA 
Certification Team. The Team should carefully consider the regulation-
specific issues and the design-specific issues to ensure that onerous 
MOCs are not demanded for simple, low-risk designs. The MOCs should 
focus on the compliance and safety issues, rather than on design 
optimization. However, applicants should be allowed to select (and 
justify) efficient and low cost MOCs, when appropriate. The applicant 
and the FAA Certification Team should strive for consensus on the MOCs. 
An open dialog is an important part of reaching that consensus.

Certification Documentation

    This policy statement describes a number of issues that the FAA 
should consider when evaluating the applicant's proposed Human Factors 
MOCs. In most cases, it will be beneficial for the applicant to review 
this policy and use it to structure the explanation or justification 
for the selection of Human Factors MOCs for the certification project. 
The applicant may provide to the FAA the information supporting the 
proposed Human Factors MOCs in any format or media that is mutually 
agreeable to the applicant and the FAA Certification Team. In general, 
a formal document is not required, although the applicant may choose to 
record the information in the relevant Certification Plan(s) or in a 
separate document. Often, the most effective and efficient means to 
convey the rationale for the selected MOCs is to hold discussions 
between the applicant and the FAA. If this latter option is used, it is 
recommended that the discussion be documented and that the conclusions 
be jointly approved.
    Additional guidance on this policy statement is provided in the 
following appendices:
     Appendix A: Partial List of 14 CFR part 25 Regulations 
Related to Human Factors Issues. (This same list was published in 
Policy Statement No. ANM-99-2. It contains detailed description of the 
regulation-specific issues, and cites relevant Advisory Circulars.)
     Appendix B: Related Documentation.
     Appendix C: Sample Human Factors Methods of Compliance 
Briefing.
     Appendix D: The Use of Design Evaluations to Support the 
Certification Process.

Appendix A--Partial List of 14 CFR Part 25 Regulations Related to Human 
Factors Issues

    This appendix provides a list of current regulations that are 
related to human factors issues. The list is divided into the 
following three categories:

[[Page 27202]]

    1. General Human Factors Requirements: Rules that deal with the 
acceptability of the flight deck and flightcrew interfaces across a 
variety of systems/features.
    2. Specific Human Factors Requirements: Rules that deal with the 
acceptability of a specific feature or function in the flight deck.
    3. Specific Crew Interface Requirements: Rules that mandate a 
specific system feature that must be implemented in an acceptable 
manner.
    This list does not include all regulations associated with 
flightcrew interfaces. However, those listed represent some of the 
requirements for which demonstrating compliance can be problematic. 
In some cases, where only subparagraphs are noted, they have been 
paraphrased for clarity. However, the FAA Certification Team should 
ensure that the applicant refers to the exact wording of the 
regulation in all plans and compliance documents.
    Where there is associated advisory material, it is cited. In 
many other cases, there may be no explicit guidance on methods of 
compliance (MOC). Therefore, it is important for the FAA 
Certification Team to carefully consider the applicant's proposed 
MOCs and attempt to come to agreement with the applicant. Rather 
than specifying an acceptable MOC for any given project, which is 
the function of advisory material, the information that is provided 
below for each rule is intended to identify issues that should be 
considered when reviewing the applicant's proposed MOC. Following 
each regulatory requirement are the following subsections, where 
appropriate:
    1. General discussion of the regulation and issue.
    2. Key questions to be asked or considered by the FAA 
Certification Team in order to help identify the MOC issues 
associated with the requirement. These regulation-specific questions 
assist the Certification Team to ensure that the applicant has 
tailored the MOCs to the potential human factors issues for the 
design being considered. The questions help provide focus on some of 
the features of designs and the way the flightcrew will use them 
that typically result in concerns about how to show compliance with 
the requirement. These lists are not all-encompassing. Rather, they 
are intended to stimulate the review process and lead to additional 
questions that are unique to the features of the specific designs. 
As new technologies emerge, the issues may change and new questions 
will need to be asked in order to identify the human factors issues 
related to the requirement.
    3. Design-related factors, such as those listed below, are 
included when appropriate to point out other more generic issues 
relevant to the MOC for the requirement:
     Novelty and past experience;
     Degree of integration and independence;
     Complexity or Level of automation;
     Criticality;
     Dynamics;
     Level of training required; and
     Subjectivity of acceptance criteria.
    It is important to remember that, for the purposes of this 
policy statement, the information is directed at reviews of the 
proposed MOCs, not the acceptability of the design itself. More 
specifically, the focus is on the general types of MOCs that the 
applicant has proposed. Details of how the compliance assessments 
are to be conducted (for example, the test designs, and the types of 
subjects) or the criteria for compliance (i.e., acceptance criteria) 
are not included. These topics will be the subjects of future policy 
statements. For example, this appendix discusses whether or not 
simulation would be appropriate for showing compliance with a given 
requirement; it does not discuss how the simulator should be used, 
what data should be collected, or how to determine whether or not 
the design is acceptable based on the data.
    Note that none of the regulations listed below are associated 
with airplane handling qualities. While such rules obviously have 
human factors implications, they have traditionally been the 
responsibility of aeronautical engineers, control system designers, 
and test pilots. The applicant may, if it so chooses, include such 
regulations in the Human Factors Certification Plan. However, the 
methods of compliance are discussed in flight test advisory material 
and FAA orders, and are outside the purview of this policy 
statement.

1. General Human Factors Requirements

    Section 25.771(a) [at amdt. 25-4]: ``Each pilot compartment and 
its equipment must allow the minimum flightcrew to perform their 
duties without unreasonable concentration or fatigue.''
    Discussion: The FAA Certification Team should carefully consider 
the aspects of the flightcrew interface that might require 
significant or sustained mental or physical effort, or might 
otherwise result in fatigue. Other factors affecting fatigue, such 
as noise and seat comfort, may also need to be evaluated. When 
reviewing the applicant's proposed MOC, the FAA Certification Team 
should consider the expected sources of fatigue, as well as how and 
when that fatigue is likely to manifest itself. Applicants have 
often successfully used comparisons to previously certificated 
designs, although testing may be warranted for new flightcrew 
interface designs or functions.
    Questions that the FAA Certification Team should ask the 
applicant when identifying the human factors-related MOC issues are 
discussed in Table A-1.

                     Table A-1.--Sec.  25.771(a): Questions To Identify Human Factors Issues
----------------------------------------------------------------------------------------------------------------
                              Question                                                Discussion
----------------------------------------------------------------------------------------------------------------
Are there any controls that will require significant peak or          If the applicant chooses to perform
 sustained muscular exertion.                                          analyses as a way to provide data in
                                                                       support of compliance, the FAA
                                                                       Certification Team should review any
                                                                       strength data and analysis methods to
                                                                       ensure that they can be generalized to
                                                                       the flight deck controls in question.
Are there any displays that will require sustained attention........  The FAA Certification Team may determine
                                                                       that the ability to time-share attention
                                                                       to the displays may require testing in a
                                                                       full simulation or in flight, in order to
                                                                       replicate the other tasks. In some cases,
                                                                       it may be possible to measure task
                                                                       performance, but subjective assessments
                                                                       are more frequently used and are likely
                                                                       to be more practical.
Are there any pilot actions that will require sustained mental        Simulation and/or flight testing, using
 concentration, especially during high workload flight phases, other   subjective measures, are typically
 than that required as part of normal flying skills.                   proposed for such issues, due to the
                                                                       complex interactions between the various
                                                                       flightcrew tasks.
Is this aircraft intended primarily for low cycle rate, long haul     The effects of multiple cycles per crew
 operations, or for high cycle rate, short haul operations.            per day or long duration flights may need
                                                                       to be factored into MOCs.
Is this a new or modified seat design...............................  It may be appropriate to determine that a
                                                                       new seat design should be tested for long-
                                                                       term comfort, to the extent that
                                                                       discomfort is expected to add to fatigue.
Are there functions of time-shared displays or controls that          In some cases, the FAA Certification Team
 increase pilot workload.                                              may accept analysis intended to show that
                                                                       there is sufficient time available to use
                                                                       the display for multiple purposes (for
                                                                       example, maintenance display functions
                                                                       time-shared with navigation). However, in
                                                                       many other cases, that information is
                                                                       likely to be usable only as supporting
                                                                       data that must be verified in simulation
                                                                       or flight test, depending on the
                                                                       functions being time-shared and the
                                                                       critical scenarios.
----------------------------------------------------------------------------------------------------------------

    Other factors to consider when reviewing the MOC are discussed 
in Table A-2.

[[Page 27203]]



                                Table A-2.--Sec.  25.771(a): Factors To Consider
----------------------------------------------------------------------------------------------------------------
                                Issue                                                 Discussion
----------------------------------------------------------------------------------------------------------------
Complexity/Level of automation......................................  Navigating though complex menu trees and
                                                                       deciphering or predicting operating modes
                                                                       for complex automation can lead to high
                                                                       concentration and memory demands. These
                                                                       demands can be especially significant if
                                                                       they occur during high stress or workload
                                                                       portions of the flight (for example,
                                                                       during non-normal conditions, severe
                                                                       weather, etc.). System description
                                                                       information, and an analysis of menu
                                                                       complexity and function accessibility, if
                                                                       provided by the applicant, can yield
                                                                       useful supporting data. However, as
                                                                       complexity and level of automation
                                                                       increases, the need for demonstrations
                                                                       and tests increases.
Criticality.........................................................  A high demand for concentration,
                                                                       especially on a single issue during a
                                                                       critical flight situation, has been shown
                                                                       to result in ``attention tunneling'' or
                                                                       ``channelized attention'' (focusing of
                                                                       attention on one task to the extent that
                                                                       other important tasks receive little or
                                                                       no attention). This phenomenon has been
                                                                       implicated in numerous accidents. The FAA
                                                                       Certification Team should ensure that the
                                                                       proposed MOCs cover such critical
                                                                       situations, if they exist.
Subjectivity of acceptance criteria.................................  Currently available and accepted methods
                                                                       for assessing concentration and mental
                                                                       fatigue usually involve subjective
                                                                       assessment, although certain applicants
                                                                       have employed physiological methods as
                                                                       methods to collect supporting data. It is
                                                                       often useful to compare the proposed
                                                                       design with previously certificated
                                                                       designs that have been shown in service
                                                                       to result in acceptable levels of
                                                                       concentration and fatigue.
----------------------------------------------------------------------------------------------------------------

    Section 25.771(e) [at amdt. 25-4]: ``Vibration and noise 
characteristics cockpit equipment may not interfere with safe 
operation of the airplane.''
    Discussion: When reviewing the proposed MOC, the FAA 
Certification Team should ensure that the applicant has carefully 
considered the types and magnitudes of vibration and noise that may 
be present under both normal and abnormal conditions. Then, the 
tasks that may be affected by vibration (for example, display 
legibility and the operation of controls) and noise (for example, 
communication and identification of aural alerts) should be 
identified. Additionally, the methods that could be used to 
determine whether the vibration or noise will unacceptably interfere 
with safe operation of the airplane should be identified.
    Unfortunately, there are no widely used and accepted vibration 
standards or testing methods which directly address whether or not 
pilots will be able to safely operate the airplane under the 
expected vibration conditions. Existing standards for workplace 
vibration primarily focus on injury to the worker after long periods 
of exposure (days, weeks, months), rather than on the ability to 
perform the required tasks (i.e., continued safe flight and 
landing).
    Actual testing of pilots in representative vibration environment 
with actual flight deck equipment (seats, controls, displays) can be 
extremely involved and expensive, especially if an applicant were to 
be required to develop a test facility with which the pilots could 
interact as with the actual airplane. The duration of the tests may 
also present a problem--it may be difficult to find a group of 
pilots willing to sit on a shaker table for the maximum duration of 
an extended twin-engine operation (ETOPS) diversion. As a result, 
showing compliance with this rule can be especially problematic.
    Questions to ask when identifying the human factors-related 
compliance issues are discussed in Table A-3.

                     Table A-2.--Sec.  25.771(e): Questions To Identify Human Factors Issues
----------------------------------------------------------------------------------------------------------------
                              Question                                                Discussion
----------------------------------------------------------------------------------------------------------------
Are there any controls requiring precise dexterity to operate (for    In some cases, the devices may already be
 example, cursor control devices, touch screens, etc.).                in service for non-essential functions.
                                                                       More thorough testing may be warranted if
                                                                       the devices are to be used for essential
                                                                       or critical functions.
Are there fine details of displays that must be interpreted during    (Self-explanatory.)
 turbulence or vibration conditions.
What are the characteristics (frequency, acceleration, amplitude) of  Are the vibration frequencies the same as
 the expected engine fan blade-loss vibrations or other expected       any relevant body resonant frequencies
 vibratory modes.                                                      (hand, arm, eye, head, abdomen, etc.)? If
                                                                       the pilots are not likely to be exposed
                                                                       to frequencies at body resonances, then
                                                                       testing may not be needed.
To what extent will the seat design dampen or amplify the vibrations  Relatively minor changes to seat cushion
 that are transmitted from the seat structure, through the seat        design can significantly affect the
 cushion, to the pilot.                                                transmission of vibrations to the pilot.
                                                                       Such changes may warrant testing,
                                                                       especially if frequencies at known body
                                                                       resonances are expected to be present at
                                                                       the seat pan.
----------------------------------------------------------------------------------------------------------------

    Other factors to consider when reviewing the MOC are discussed 
in Table A-4.

                                Table A-4.--Sec.  25.771(e): Factors To Consider
----------------------------------------------------------------------------------------------------------------
                                Issue                                                 Discussion
----------------------------------------------------------------------------------------------------------------
Novelty/past experience.............................................  Conventional controls, such as pushbuttons
                                                                       and rotary knobs can generally be shown
                                                                       to be compliant via similarity, providing
                                                                       that they have conventional
                                                                       characteristics (size, force/friction,
                                                                       tactile feedback) and the vibration
                                                                       environment is not expected to be severe
                                                                       (see discussion above).
Criticality.........................................................  Are the tasks that require a high degree
                                                                       of visual resolution or manual dexterity
                                                                       likely to be critical to continued safe
                                                                       flight and landing in situations that
                                                                       result in flight deck vibration? Such a
                                                                       condition may warrant testing, if the
                                                                       controls/displays are non-conventional or
                                                                       if the vibration is expected to be
                                                                       unusual.
Subjectivity of acceptance criteria.................................  Analysis and testing of components could
                                                                       be used to show that no significant
                                                                       vibration problems are present. However,
                                                                       in cases that cannot be clearly disposed
                                                                       of through similarity or analysis, the
                                                                       FAA Certification Team may wish to
                                                                       request testing with human subjects.
                                                                       There is no standardized and accepted
                                                                       subjective measurement method for this
                                                                       requirement. As of the time of publishing
                                                                       this policy statement, the only
                                                                       certification evaluations in an actual
                                                                       vibratory environment have involved a
                                                                       subjective assessment of the
                                                                       acceptability of the vibration, after a
                                                                       short duration exposure.
----------------------------------------------------------------------------------------------------------------

    Other factors relative to finding compliance with Sec. 25.771(e) 
are:
    1. Improved MOCs and standards for this requirement are being 
considered for development. As the FAA and applicants become more 
experienced in dealing with

[[Page 27204]]

this issue, the FAA will provide more information on MOCs.
    2. The FAA Aircraft Certification Offices (ACO) should use care 
when assessing the proposed MOCs, due to the difficulty and cost of 
doing full-scale testing. The ACOs should work closely with the 
applicant to develop sufficient evidence to make a supportable 
determination regarding the need for such testing.
    Section 25.773(a)(1) [at amdt. 25-72]: ``Each pilot compartment 
must be arranged to give the pilots sufficiently extensive, clear, 
and undistorted view, to enable them to safely perform any maneuvers 
within the operating limitations of the airplane, including takeoff, 
approach, and landing.''
    Discussion: The applicant should carefully consider the methods 
of compliance described in Advisory Circular (AC) 25.773-1, ``Pilot 
compartment View for Transport Category Airplanes,'' dated January 
8, 1993.
    Section 25.773(a)(2) [at amdt. 25-72]: ``Each pilot compartment 
must be free of glare and reflections that could interfere with the 
normal duties of the minimum flightcrew.''
    Discussion: The applicant may be able to develop analytical 
techniques that identify potential sources of glare and reflections, 
as a means for reducing the risk of problems identified after the 
major structural features have been committed. Mock-ups also may be 
a useful means for early assessments. However, analysis results 
typically should be verified in an environment with a high degree of 
geometric and optical fidelity. Both internal sources of reflections 
(for example, area and instrument lighting) and external sources of 
reflection (for example, shafting sunlight) so should be considered. 
Compliance can be greatly affected by the relative geometry of the 
reflective surfaces (windows, glass instrument faces, etc) and the 
direct/indirect light sources (instrumentation, area lighting, white 
shirts, etc). In addition, the reflective characteristics of the 
surfaces (windows, instruments) can vary greatly with material and 
manufacturing processes. Therefore, it is important that those 
surfaces are representative of those that will be present in the 
airplane.
    Factors to consider when reviewing the MOC are listed in Table 
A-5.

                              Table A-5.--Sec.  25.773 (a)(2): Factors To Consider
----------------------------------------------------------------------------------------------------------------
                                Issue                                                 Discussion
----------------------------------------------------------------------------------------------------------------
Degree of integration/independence..................................  This means that testing or evaluations
                                                                       usually must be conducted using an
                                                                       environment with accurate geometry.
Criticality.........................................................  If reflections are likely to be present in
                                                                       the forward windshield, they must be
                                                                       carefully evaluated for the possibility
                                                                       of interference with external visual
                                                                       scanning during critical phases of flight
                                                                       (especially takeoff and landing).
                                                                       Similarly, potential reflections on
                                                                       primary flight displays or other
                                                                       important display surfaces should get
                                                                       special attention.
Subjectivity of acceptance criteria.................................  Even though objective standards for
                                                                       reflectivity do not exist, the FAA
                                                                       Certification Team should encourage
                                                                       applicants to measure the intensity of
                                                                       reflections as an objective means for
                                                                       comparison with existing designs.
----------------------------------------------------------------------------------------------------------------

    Section 25.777(a) [at amdt. 25-46]: ``Each cockpit control must 
be located to provide convenient operation and to prevent confusion 
and inadvertent operation.''
    Discussion: While applicants sometimes use physical mock-ups for 
preliminary evaluations, such devices often have insufficient 
fidelity to allow findings of compliance. Simulators, if available, 
provide a more powerful evaluation environment, because they allow 
the evaluation to take place in a flight scenario that may influence 
convenience and inadvertent operation. Simulator evaluations also 
may reduce the need for flight testing.
    Questions to ask when identifying the human factors-related 
compliance issues are discussed in Table A-6.

                    Table A-6.--Sec.  25.777(a): Questions To Identify Human Factors Issues
----------------------------------------------------------------------------------------------------------------
                              Question                                                Discussion
----------------------------------------------------------------------------------------------------------------
Are there situations in which a pilot will be required to reach       Are there other circumstances where the
 across the centerline of the flight deck to operate controls on the   pilot will need to reach past prominent
 other side (for example, the landing gear handle).                    controls in order to accomplish flight
                                                                       deck tasks, whether or not those tasks
                                                                       are ``required'' for operation of the
                                                                       airplane (for example, reaching for
                                                                       something stowed behind a seat, or
                                                                       reaching for food from the flight
                                                                       attendant)? Such cases may provide
                                                                       justification for the FAA Certification
                                                                       Team to request specific evaluations
                                                                       using computer modeling, mock-ups, the
                                                                       flight simulators, and/or the airplane.
Are there safety consequences if the pilot inadvertently activates a  If safety is not a significant issue, and
 similar control that is in proximity to the control in question.      if the error will be obvious and easy to
                                                                       correct, then the MOCs necessary to fully
                                                                       evaluate the possibility of confusion may
                                                                       be reduced.
----------------------------------------------------------------------------------------------------------------

    Factors to consider when reviewing the MOC are discussed in 
Table A-7.

                                Table A-7.--Sec.  25.777(a): Factors To Consider
----------------------------------------------------------------------------------------------------------------
                                Issue                                                 Discussion
----------------------------------------------------------------------------------------------------------------
Complexity/Level of automation......................................  The proposed MOC should address the ease
                                                                       of use and inadvertent operation of
                                                                       control functions that are accessed
                                                                       through menu logic.
Criticality.........................................................  Determine if the controls for which
                                                                       inadvertent operation has significant
                                                                       safety implications have appropriate
                                                                       guards or other means of protection. Such
                                                                       safeguards typically reduce both
                                                                       inadvertent operation and convenience, so
                                                                       the proposed evaluations should include
                                                                       both aspects.
----------------------------------------------------------------------------------------------------------------

    Section 25.777(c) [at amdt. 25-46]: ``The controls must be 
located and arranged, with respect to the pilot's seats, so that 
there is full and unrestricted movement of each control without 
interference from the cockpit structure or the clothing of the 
minimum flightcrew when any member of this flightcrew, from 5'2" to 
6'3" in height, is seated with the seat belt and shoulder harness 
fastened.''
    Discussion: While this rule directly addresses body height, 
other body dimensions, such as sitting height, sitting shoulder 
height, arm length, hand size, etc, can have significant effects on 
the geometric acceptability of the flight deck for pilots within the 
specified height range. These other dimensions do not necessarily 
correlate well with height or with each other. The MOC should 
reasonably account for these variables. The applicant may choose to 
use analytical methods, such as computer modeling of the flight deck 
and the pilots, for early risk reduction and to supplement 
certification evaluations using human subjects. Computer modeling 
allows for more

[[Page 27205]]

control over the dimensions of the pilot model, and thus, may allow 
the assessment of otherwise unavailable combinations of body 
dimensions.
    The FAA Certification Team should carefully consider the 
advantages and limitations of each of these methods when assessing 
the applicant's proposal to use such data in support of findings of 
compliance. In addition, the FAA Certification Team should usually 
require final verification in the airplane, because even simulators 
rarely reproduce all of the aspects of the flight geometry that may 
be relevant to this requirement.
    Section 25.1301(a) [original amdt.]: ``Each item of installed 
equipment must be of a kind and design appropriate to its intended 
function.''
    Discussion: The applicant might propose a number of methods for 
showing compliance with this requirement, with respect to human 
factors. For example, service experience may be an effective means 
for assessing systems with well-understood, successful crew 
interfaces, assuming that other factors, such as changes in the 
operational environment, do not affect the relevance of that 
experience. System descriptions can be used to define the intended 
functions of the systems, along with those of the components or 
other elements of the system (for example, the intended function of 
each piece of data on a display). Various requirements analysis 
techniques can be used to show that the information that the pilot 
needs to perform key tasks is available, usable, and timely. 
Simulation may be used to verify that properly trained pilots can 
adequately perform all required tasks, using the controls and 
displays provided by the design, in realistic scenarios and 
timelines. Finally, flight tests can be used to investigate specific 
normal and abnormal operational scenarios to show that the system 
adequately supports the pilots' tasks, in accordance with the stated 
intended functions. For additional guidance on electronic display 
systems, see FAA AC 25-11, Transport Category Airplane Electronic 
Display Systems,'' dated July 16, 1987,'' sections 6 and 7, as 
appropriate.
    Section 25.1309(b)(3) [at amdt. 25-41]: ``*  * * Systems, 
controls, and associated monitoring and warning means must be 
designed to minimize crew errors that could create additional 
hazards.''
    Discussion: The applicant may propose analyses of crew 
procedures in response to system faults. This can be especially 
useful in cases where the applicant wishes to take certification 
credit (for example, in a fault tree analysis) for correct pilot 
response to a system failure. A crew procedure analysis could be 
supported by qualitative evaluations that compare actual procedures 
to procedure design philosophies by developing measures of procedure 
complexity, or by other techniques that focus on procedure 
characteristics that impact the likelihood of crew errors. 
Simulation testing can be helpful in demonstrating that the design 
is not prone to crew errors.
    Section 25.1321(a) [at amdt. 25-41]: ``Each flight, navigation, 
and powerplant instrument for use by any pilot must be plainly 
visible to him from his station with the minimum practicable 
deviation from his normal position and line of vision when he is 
looking forward along the flight path.''
    Discussion: The applicant may wish to perform analyses of the 
visual angles to each of the identified instruments. Final 
assessments of the acceptability of the visibility of the 
instruments may require a simulator with a high degree of geometric 
fidelity and/or the airplane. For more information on electronic 
display systems, see FAA AC 25-11, section 7, as appropriate.
    Section 25.1321(e) [at amdt. 25-41]: ``If a visual indicator is 
provided to indicate malfunction of an instrument, it must be 
effective under all probable cockpit lighting conditions.''
    Discussion: Demonstrations and tests intended to show that these 
indications of instrument malfunctions, along with other indications 
and alerts, are visible under the expected lighting conditions will 
typically use production quality hardware and careful control of 
lighting conditions (for example, dark, bright forward field, 
shafting sunlight). Simulators and aircraft are often used, although 
supporting data from laboratory testing also may be useful.
    Section 25.1523 [at amdt. 25-3]: ``The minimum flightcrew must 
be established so that it is sufficient for safe operation, 
considering:
    (a) The workload on individual crewmembers;
    (b) The accessibility and ease of operation of necessary 
controls by the appropriate crewmember; and
    (c) The kind of operation authorized under Sec. 25.1525.''
    Discussion: The criteria used in making the determinations 
required by this section are set forth in Appendix D of 14 CFR part 
25. For additional information, see:
     AC 25.1523-1, ``Minimum Flightcrew,'' dated February 2, 
1993; and
     AC 25-11, section 5.b.
    Section 25.1543(b) [at amdt. 25-72]: ``Each instrument marking 
must be clearly visible to the appropriate crewmember.''
    Discussion: The applicant may choose to use computer modeling to 
provide preliminary analysis showing that there are no visual 
obstructions between the pilot and the instrument markings. Where 
head movement is necessary, such analyses also can be used to 
measure its magnitude. Other analysis techniques can be used to 
establish appropriate font sizes, based on research-based 
requirements. Mock-ups also can be helpful in some cases. The data 
collected in these analysis and assessments are typically used to 
support final verification in the flight deck, using subjects with 
vision that is representative of the pilot population, in 
representative lighting conditions. For more information on 
electronic display systems, see AC 25-11, sections 6 and 7, as 
appropriate. For more information on marking of power plant 
instruments, see AC 20-88A, ``Guidelines on the Marking of Aircraft 
Powerplant Instruments (Displays),'' dated 9/30/85.

2. Specific Human Factors Requirements

    Section 25.785(g) [at amdt. 25-88]: ``Each seat at a flight deck 
station must have a restraint system * * * that permits the flight 
deck occupant, when seated with the restraint system fastened, to 
perform all of the occupant's necessary flight deck functions.''
    Discussion: The applicant may choose to develop a list of what 
it considers to be necessary flight deck functions, under normal and 
abnormal conditions. Methods similar to those used to show 
compliance with Sec. 25.777 also may be appropriate for this 
paragraph, with the additional consideration of movement constraints 
imposed by the full restraint system.
    Factors to consider when reviewing the MOC are discussed in 
Table A-8:

            Table A-8.--Sec.  25.785(g): Factors To Consider
------------------------------------------------------------------------
              Issue                              Discussion
------------------------------------------------------------------------
Dynamics.........................  If the restraint system could lock-up
                                    during turbulence or vibration, and
                                    thus restrict reach, the MOC may
                                    need to include evaluations under
                                    these conditions.
------------------------------------------------------------------------

    Section 25.785(l) [at amdt. 25-88]: ``The forward observer's 
seat must be shown to be suitable for use in conducting the 
necessary enroute inspections.''
    Discussion: The applicant may choose to develop a set of 
requirements (for example, what must be seen and reached) based on 
the expected tasks to be performed by an inspector. The FAA 
Certification Team personnel may wish to consult with FAA Flight 
Standards personnel to validate these requirements. Computer-based 
analysis and/or mock-ups can be used to develop supporting data (for 
example, visibility of displays); evaluation of enroute inspection 
scenarios can be used to verify that all required tasks can be 
performed. Since the geometric relationship between the observer's 
seat and the rest of the flight deck (including the pilots) is 
important, the evaluations often must occur in the actual airplane.
    Section 25.1141(a) [at amdt. 25-72]: ``Each powerplant control 
must be located so that it cannot be inadvertently operated by 
persons entering, leaving, or moving normally in the cockpit.''
    Discussion: This type of assessment typically requires at least 
a physical mock-up, due to limitations in the ability to adequately 
model ``normal'' movement in the cockpit. Evaluations should be 
designed:
     To include cases in which the pilots must reach across 
the area surrounding the powerplant controls; and
     To look for places where pilots will naturally place 
their hands and feet during ingress and egress, and during cruise.
    Subjective assessments by the FAA Designated Engineering 
Representative (DER) or FAA pilots would be the most typical method 
for assessing the likelihood and seriousness of any inadvertent 
operation of the powerplant controls.
    Section 25.1357(d) [original amdt.]: ``If the ability to reset a 
circuit breaker or replace a fuse is essential to safety during 
flight, that circuit breaker or fuse must be located and

[[Page 27206]]

identified so that it can be readily reset or replaced in flight.''
    Discussion: The applicant may choose to use methods similar to 
those employed for Sec. 25.777 to demonstrate the ability of the 
pilot to reach the specific circuit protective device(s). The 
applicant also should consider how to evaluate the ability of the 
pilot to readily identify the device(s), whether they are installed 
on a circuit breaker panel or controlled using an electronic device 
(i.e., display screen on which the circuit breaker status can be 
displayed and controlled).
    A necessary question to ask when identifying the human factors-
related compliance issues is discussed in Table
A-9.

                    Table A-9.--Sec.  25.1357(d): Questions To Identify Human Factors Issues
----------------------------------------------------------------------------------------------------------------
                              Question                                                Discussion
----------------------------------------------------------------------------------------------------------------
Are there any crew procedures which require the flightcrew to reset   If not, it may be reasonable for an
 a circuit breaker or replace a fuse.                                  applicant to state this and to provide
                                                                       verification via published flightcrew
                                                                       specific procedures.
----------------------------------------------------------------------------------------------------------------

    Section 25.1381(a)(2) [at amdt. 25-72]: ``The instrument lights 
must be installed so that * * * (ii) no objectionable reflections 
are visible to the pilot.''
    Discussion: See the discussion of Sec. 25.773(a), above.

3. Specific Crew Interface Requirements

    Section 25.773(b)(2)(i) [at amdt. 25-72]: ``The first pilot must 
have a window that is openable * * * and gives sufficient protection 
from the elements against impairment of the pilot's vision.''
    Discussion: While the applicant may perform analyses to show the 
visual field through the openable window, due to the nature of the 
task (landing the airplane by looking out the opened window), it is 
likely that a flight test would be the most appropriate method of 
compliance. Assessment of the forces required to open the window 
under flight conditions also may be needed.
    Section 25.1322 [at amdt. 25-38]: ``If warning, caution, or 
advisory lights are installed in the cockpit, they must, unless 
otherwise approved by the Administrator, be--
    (a) Red, for warning lights (lights indicating a hazard which 
may require immediate corrective action);
    (b) Amber, for caution lights (lights indicating the possible 
need for future corrective action);
    (c) Green for safe operation lights; and
    (d) Any other color, including white, for lights not described 
in paragraphs (a) through (c) of this section, provided the color 
differs sufficiently from the colors prescribed in paragraphs (a) 
through (c) of this section to avoid possible confusion.''
    Discussion: Compliance with this requirement is typically shown 
by a description of each of the warning, caution, and advisory 
lights (or their electronic equivalents). Evaluations may also be 
useful to verify the chromaticity (for example, red looks red, amber 
looks amber) and discriminability (i.e., colors can be distinguished 
reliably from each other) of the colors being used, under the 
expected lighting levels. These evaluations can be affected by the 
specific display technology being used, so final evaluation with 
flight quality hardware is sometimes needed. A description of a 
well-defined color coding philosophy which is consistently applied 
across flight deck systems can be used to show how the design avoids 
``possible confusion''. For additional information, see AC 25-11, 
section 5.a.

Appendix B--Related Documents

    1. Advisory Circulars (AC): The specified sections of the ACs 
listed below concern selecting a method of compliance (test, 
inspection, simulation, etc.), rather than identifying specific 
design features that will generally be accepted as compliant.
    a. AC 25.1309-1B, ``System Design and Analysis'' [draft]: This 
AC identifies certain human factors assessments that should be done 
as part of the overall safety assessments intended to show 
compliance with Sec. 25.1309. Section 9 (subparagraphs on ``Crew and 
Maintenance Actions'') provides some information on determining if 
failure indications are considered to be recognizable, and if the 
required actions cause an excessive workload.
    b. AC 25-11, ``Transport Category Airplane Electronic Display 
Systems,'' dated July 16, 1987: This AC applies to systems using 
cathode ray tube (CRT)-based technology, but the FAA plans to update 
it to cover other display technologies [for example, liquid crystal 
displays (LCD)]. The AC is used to support compliance with a number 
of regulations, including the following, also cited in this policy 
statement, that are related to human factors aspects of the 
flightcrew interfaces:
     Sec. 25.771, Pilot compartment.
     Sec. 25.777, Cockpit controls.
     Sec. 25.1141, Powerplant controls: general.
     Sec. 25.1301, Equipment: Function and installation.
     Sec. 25.1309, Equipment, systems, and installations.
     Sec. 25.1322, Warning, caution, and advisory lights.
     Sec. 25.1381, Instrument lights.
     Sec. 25.1523, Minimum flightcrew.
     Sec. 25.1543, Instrument markings: general.
    Several sections of AC 25-11 identify display system 
characteristics that can be verified by inspection. The information 
provided in the following sections of the AC may be useful in 
assessing the applicant's other proposed evaluation methods:
     Section 4.b.(1): General Certification Considerations, 
Compliance Considerations, Human Factors. This section includes a 
discussion of the use of simulation and in-flight evaluations.
     Section 6.: Display Visual Characteristics. Various 
subsections of this section contain guidance on evaluation and test 
conditions and methods.
    c. AC 20-88A, ``Guidelines on the Markings of Aircraft 
Powerplant Instruments (Displays),'' dated September 30, 1985: This 
AC provides information related to marking of aircraft powerplant 
instruments and electronic displays (cathode ray tubes, etc.). The 
AC is used to support compliance with a number of regulations, 
including the following, that are related to human factors aspects 
of the flightcrew interfaces:
     Sec. 25.1541, Placards and markings: General.
     Sec. 25.1543, Instrument markings: General.
     Sec. 25.1549, Powerplant and auxiliary power unit 
instruments.
    d. AC 25.1523-1, ``Minimum Flightcrew,'' dated February 2, 1993: 
This AC provides information related to compliance with Sec. 25.1523 
and Appendix D of 14 CFR part 25, which contain the certification 
requirements for the minimum number of flightcrew personnel on 
transport category airplanes.
    e. AC 25.773-1, ``Pilot Compartment View Design 
Considerations,'' dated January 8, 1993: This AC defines a method 
for determining the clear view area of the flight deck windows. In 
practice, this approach can be carried out using direct measurements 
of an actual flight deck (or high fidelity physical flight deck), or 
using computer analysis of a 3-D computer aided design (CAD) model 
of the flight deck. Referenced in this AC is Society of Automotive 
Engineers (SAE) Aerospace Recommended Practice (ARP) 4101/2 (which 
replaced AS 580B), ``Pilot Visibility from the Flight Deck,'' dated 
February 1989.

2. Other References

    a. Technical Report DPT/FAA/RD-93/5, ``Human Factors for Flight 
Deck Certification Personnel,'' dated July 1993, which can be 
ordered through the National Technical Information Service (http://www.ntis.gov/): Key chapters of this document include:
     Chapter 8: Timesharing, Workload, and Human Error.
     Chapter 11: Workload Assessment.
     Chapter 12: Human Factors Testing and Evaluation.

Appendix C--Sample Human Factors Methods of Compliance Briefing

    This sample briefing is intended to provide examples of the 
types of information that could be included in such a briefing. Keep 
the following in mind while reviewing it:
     It is based on a totally hypothetical certification 
program, and no connection to any real system or certification 
program is intended or implied. For more information on this 
hypothetical program, see the FAA policy on human factors 
certification plans, contained Appendix C of Policy Statement No. 
ANM-99-2. The extracts from the human

[[Page 27207]]

factors certification compliance matrix contained in this policy 
statement are drawn from that appendix.
     This sample briefing should not be considered 
comprehensive. The examples are intended to be illustrative, but do 
not necessarily include all of the issues, even for the hypothetical 
program.
     The methods of compliance are intended to show the 
methods that a hypothetical applicant might have proposed for the 
project. It should not be construed as describing an acceptable list 
of methods for any real program. Such methods would have to be 
discussed and agreed upon within the context of a specific program.
     The ``Deliverable Products'' column in the compliance 
matrix identifies what the hypothetical applicant will produce to 
substantiate compliance. The titles of reports represent examples of 
how an applicant might choose to package the information.
     Finally, the sample briefing is not intended to specify 
the format of how this information is provided to the FAA; rather, 
it is meant to provide guidance only on an acceptable structure and 
recommended content. Alternative methods for providing this 
information are acceptable, such as adding it to the Certification 
Plan or providing it in a separate document. For large, complex 
projects, it could be a part of the overall project, without being a 
separate piece. The primary intent is to illustrate how an applicant 
could provide information to the FAA, explaining why and how the 
proposed methods of compliance are sufficient.

[Hypothetical]

Human Factors Certification Methods of Compliance for the Electronic 
Approach Chart System (EACS)

1. Introduction

    a. Project: This project seeks a Supplemental Type Certificate 
(STC) for the installation of an Electronic Approach Chart System 
(EACS) in Guerin Model 522 airplanes. The intent of the EACS is to 
provide an alternative to the use of paper approach charts.
    b. Installation: The ECAS will be installed so that it is 
physically and functionally integrated into the flight deck.
    c. Data loading: System data will use existing on-board data 
loading capabilities.
    d. System type: The EACS will be certified as a non-essential 
system.

2. System Description

    a. Intended Function: The EACS uses a panel-mounted Active 
Matrix Liquid Crystal Display (AMLCD) to display approach charts for 
the pilots to use on the ground and in flight. The key functions 
include the following:
    (1) During the preflight preparation: 
    (a) The pilot will use the system to call up and review the 
approach charts for the destination airport and selected alternates.
    (b) The pilot will be able to ``mark'' the appropriate charts 
for quick retrieval later in the flight.
    (c) If initiated by the pilot, the system will be able to query 
the Flight Management System (FMS) to pre-identify the appropriate 
charts, based on the flight plan.
    (2) During flight (normal operations): 
    (a) The pilot will quickly access the pre-selected approach 
charts. Charts that were not pre-selected also will be accessible.
    (b) The pilot will be able to manipulate the display of the 
chart to show only the information relative to the planned route of 
flight.
    (c) The pilot will be able to select the appropriate approach 
parameters (transition, approach navigation aids, minimums, etc.) 
using the EACS. Upon pilot initiation, the EACS will load these 
selections into the other systems on the airplane [for example, the 
approach navaids will be sent to the FMS for autotuning, and 
decision height (DH) will be sent to the altitude alerting system 
and display system]. For a complete list of EACS functions, see the 
EACS System Description Document.
    (3) During flight (non-normal operations, i.e., requiring an 
emergency diversion): In addition to those functions available for 
normal operations, the EACS provides the following functionality to 
support emergency diversions:
    (a) When the pilot selects the ALTERNATE AIRPORT function on the 
FMS, the FMS automatically identifies the five nearest airports that 
meet the landing requirements for the airplane. These airports will 
be automatically transmitted to the EACS, which will preselect them 
(mark them for quick retrieval).
    (b) At the pilot's request, the EACS will display a listing of 
the diversion airports and allow the pilot to quickly review the 
approach charts and select the desired approach. As in normal 
operations, this selection will be automatically transmitted to the 
FMS and other using systems.

    Note: For more detail on the EACS, see the Human Factors 
Certification Plan and System Description Document.

3. Proposed Methods of Compliance

    a. The following slides provide a discussion of the proposed 
Method of Compliance for each of the human factors rules identified 
in the EACS Human Factors Certification Plan.
    b. The rules are organized into the following categories for 
discussion:
    (1) Flightcrew workload.
    (2) Noise and vibration.
    (3) Internal/external vision.
    (4) Flight deck lighting.
    (5) Flight deck arrangement.
    (6) System failures and alerting.
    (7) Miscellaneous.

4. Simulator

    a. A rudimentary PC-based simulator will be used for some 
evaluations.
    b. The simulator has representative (generic) flight controls, 
autopilot, and performance models. (The EACS has no interaction with 
aircraft performance, so high fidelity is not needed.)
    c. The simulator includes the same flight management computer 
(FMC) and main displays as the STC configuration. The EACS will be 
installed only on the captain's side in the simulator. Any 
evaluations requiring participation by both crew members will be 
conducted on the test airplane.
    d. Installation geometry of the simulator is approximately 
equivalent to the actual installation. Any evaluations requiring 
accurate installation geometry will be conducted on the test 
airplane.
    e. Because EACS does not interact with other airplane systems 
(pressurization, hydraulics, etc), those systems are not replicated 
in the simulator. It will be possible to fail the EACS, simulating 
an electrical bus failure.
    f. The simulator will be used primarily to assess EACS/FMS 
interaction and to perform comparisons between use of paper charts 
and EACS.

5. Flightcrew Workload

--------------------------------------------------------------------------------------------------------------------------------------------------------
         Section [amdt.level]                            Human factors requirements                   Method(s) of  compliance     Deliverable product
--------------------------------------------------------------------------------------------------------------------------------------------------------
25.771(a) [at amdt. 25-4].............  Each pilot compartment and its equipment must allow the       Analysis          Workload Certification
                                         minimum flightcrew to perform their duties without           Simulator          Report.
                                         unreasonable concentration or fatigue.                       evaluations
                                                                                                      Flight test
25.1523 [at amdt. 25-3]...............  The minimum flightcrew must be established so that it is      Simulator          Demonstration
                                         sufficient for safe operation, considering:                  demonstration              Report.
                                                                                                       Flight test       Flight Test
                                                                                                                                 Report.
                                        (a) The workload on individual crewmembers;
                                        (b) The accessibility and ease of operation of necessary
                                         controls by the appropriate crewmember; and

[[Page 27208]]

 
                                        (c) the kind of operation authorized under Sec.  25.1525.
                                        The criteria used in making the determinations required by
                                         this section are set forth in Appendix D of 14 CFR part
                                         25.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    a. The EACS functions are centered around the selection and 
review of approach charts. Although we do not anticipate any 
certification issues with respect to showing compliance with the 
above rules (workload reduction is a central goal for this system), 
we will perform a workload evaluation in order to show the benefits 
of the system.
    b. Analysis will be used to identify all of the pilot activities 
associated with identification, retrieval, review, and use of the 
charts, along with any other tasks necessary for operation of the 
EACS.
    c. Simulator evaluations or demonstrations will be used to 
measure task times and error rates for conventional charts and the 
EACS. Subjective measures of task difficulty and workload will be 
taken. Normal and non-normal scenarios will be included. Subjects 
will include DER and customer pilots.
    d. Limited flight tests with FAA pilots will be used to confirm 
the analyses and simulator tests.

6. Vibration and Noise

--------------------------------------------------------------------------------------------------------------------------------------------------------
         Section [amdt.level]                            Human factors requirements                   Method(s) of  compliance     Deliverable product
--------------------------------------------------------------------------------------------------------------------------------------------------------
25.771(e) [at amdt. 25-4].............  Vibration and noise characteristics of cockpit equipment     Flight test                Flight Test Report.
                                         may not interfere with safe operation of the airplane.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    a. Controls are conventional in design and similar to other 
certificated systems:
    (1) Function keys [similar to keys on current Master Control 
Display Unit (MCDU)].
    (2) Touch screen [similar to certain Aircraft Communications 
Addressing and Reporting System (ACARS) units].
    (3) Brightness control (conventional rotary knob).
    b. The EACS is a supplemental system, so we suggest that full 
testing of usability in high vibration and turbulence is not 
required (pilot can revert to paper charts).
    c. During flight test program, turbulence will be sought out for 
pilot subjective evaluations of EACS usability. However, 
certification will not be contingent upon testing in turbulence.

7. Internal/External Vision and Flight Deck Lighting

--------------------------------------------------------------------------------------------------------------------------------------------------------
         Section [amdt.level]                            Human factors requirements                   Method(s) of  compliance     Deliverable product
--------------------------------------------------------------------------------------------------------------------------------------------------------
25.773(a)(1) [at amdt. 25-72].........  Each pilot compartment must be arranged to give the pilots   Similarity                 Vision Certification
                                         sufficiently extensive, clear, and undistorted view, to                                 Report.
                                         enable them to safely perform any maneuvers within the
                                         operating limitations of the airplane, including takeoff,
                                         approach, and landing.
25.1321(a) [at amdt. 25-41]...........  * * * Each flight, navigation, and powerplant instrument      System             Installation
                                         for use by any pilot must be plainly visible to him from     description                Drawings
                                         his station with the minimum practicable deviation from      Analysis           Vision
                                         his normal position and line of vision when he is looking    Flight test        Certification Report
                                         forward along the flight path.                                                          Flight Test
                                                                                                                                 Report.
25.1543(b) [at amdt. 25-72]...........  Each instrument marking must be clearly visible to the       Ground test                 Vision
                                         appropriate crewmember.                                                                 Certification Report
                                                                                                                                 Ground Test
                                                                                                                                 Report.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    a. Because this system will be fully integrated into the 
existing instrument panels, external vision will be unaffected by 
the installation.
    b. Because all pilots are intended to position themselves at the 
Design Eye Reference Point (DERP), there will be little pilot-to-
pilot variability with respect to the visibility of the display. 
Thus, visibility will be easily confirmed during flight test. Risk 
for this installation is expected to be very low.
    c. The visual angles from the DERP to the EACS will be 
determined and compared to other display systems, as well as the 
clipboard where pilots currently place their paper charts.
    d. Readability will be assessed (using a questionnaire) in the 
airplane during ground testing, concurrently with the lighting 
tests. This will allow evaluation of readability under all expected 
lighting conditions.

[[Page 27209]]

8. Flight Deck Lighting

--------------------------------------------------------------------------------------------------------------------------------------------------------
         Section [amdt.level]                            Human factors requirements                   Method(s) of  compliance     Deliverable product
--------------------------------------------------------------------------------------------------------------------------------------------------------
25.773(a)(2) [at amdt. 25. 72]........  Each pilot compartment must be free of glare and             Ground test                Lighting Certification
                                         reflections that could interfere with the normal duties of                              Report.
                                         the minimum flightcrew.
25.1321(e) [at amdt. 25-41]...........  If a visual indicator is provided to indicate malfunction     Similarity         System
                                         of an instrument, it must be effective under all probable    Flight test        Description and
                                         cockpit lighting conditions.                                 Ground test        Statement of
                                                                                                                                 Similarity.
                                                                                                                                 Flight Test
                                                                                                                                 Report.
25.1381(a)(2) [at amdt. 25-72]........  The instrument lights must be installed so that (ii) no      Ground test                Flight Test Report.
                                         objectionable reflections are visible to the pilot.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    a. This system uses a conventional normally white Active Matrix 
Liquid Crystal Display (AMLCD) display.
    b. The AMLCD is provided by a vendor who has produced similar 
display glass for other previously certificated flight deck systems.
    c. In general, visibility/lighting risk should be low for this 
display.
    d. Ground tests will cover the following lighting cases:
    (1) Night (windows will be covered), and
    (2) Shafting sunlight (using a hand held spotlight).
    e. Flight tests will cover the following lighting cases:
    (1) Bright forward field (flying into brightly lit clouds), and
    (2) Bright forward point light source (flying toward the sun).
    f. Reflections that might be caused by the EACS, or that might 
be present on the EACS display, will be assessed subjectively during 
the ground test.

9. Flight Deck Arrangement

--------------------------------------------------------------------------------------------------------------------------------------------------------
         Section [amdt.level]                            Human factors requirements                   Method(s) of  compliance     Deliverable product
--------------------------------------------------------------------------------------------------------------------------------------------------------
25.777(a) [at amdt. 25-46]............  Each cockpit control must be located to provide convenient    Ground test       Flight Deck
                                         operation and to prevent confusion and inadvertent           Flight test        Anthropometry
                                         operation.                                                                              Certification Report.
25.777(c) [at amdt. 25-46]............  The controls must be located and arranged, with respect to   Ground test                Flight Deck
                                         the pilot's seats, so that there is full and unrestricted                               Anthropometry
                                         movement of each control without interference from the                                  Certification Report.
                                         cockpit structure or the clothing of the minimum
                                         flightcrew when any member of this flightcrew, from 5'2"
                                         to 6'3" in height, is seated with the seat belt and
                                         shoulder harness fastened.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    a. Reach to the EACS will be shown by using a representative 
sample of people within the required height range.
    b. Ground tests will show that the EACS does not interfere with 
use of the nose wheel steering tiller and oxygen masks (the only 
controls in the vicinity of the EACS).

10. Miscellaneous:

--------------------------------------------------------------------------------------------------------------------------------------------------------
         Section [amdt.level]                            Human factors requirements                   Method(s) of  compliance     Deliverable product
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sec.  25.1309(b)(3) [at amdt. 25-41]..  . . . Systems, controls, and associated monitoring and        Hazard             Fault Tree
                                         warning means must be designed to minimize crew errors       assessment                 Analyses.
                                         that could create additional hazards.                        Simulator          Demonstration
                                                                                                      demonstration              Report.
Sec.  25.1322 [at amdt. 25-38]........  If warning, caution, or advisory lights are installed in     Configuration description  System Description
                                         the cockpit, they must, unless ortherwise approved by the                               Document.
                                         Administrator, be--
                                        (a) Red, for warning lights (lights indicating a hazard
                                         which may require immediate corrective action);
                                        (b) Amber, for caution lights (lights indicating the
                                         possible need for future corrective action);
                                        (c) Green for safe operation lights; and
                                        (d) Any other color, including white, for lights not
                                         described in paragraphs (a) through (c) of this section,
                                         provided the color differs sufficiently from the colors
                                         prescribed in paragraphs (a) through (c) of this section
                                         to avoid possible confusion.

[[Page 27210]]

 
Sec.  25.773(b)(2)(i)[at amdt. 25-72].  The first pilot must have a window that is openable * * *    Ground test (to verify no  Flight Test Report.
                                         and gives sufficient protection from the elements against    interference with window
                                         impairment of the pilot's vision.                            opening)
Sec.  25.1301(a) [original amdt.].....  Each item of installed equipment must be of a kind and        System             Flight test
                                         design appropriate to its Document intended function.        description                System
                                                                                                      Simulator          Description Document.
                                                                                                      demonstration              Demonstration
                                                                                                                                 Report.
                                                                                                                                 Flight Test
                                                                                                                                 Report.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    a. Regarding Sec. 25.1309(b)(3):
    (1) The EACS failure annunciations, along with their associated 
crew procedures, will be demonstrated in the simulator.
    (2) The annunciation, data transfer inhibits, and crew 
procedures are very simple and straight-forward. We believe this to 
be a very low risk issue.
    b. Regarding Sec. 25.1301(a):
    (1) A checklist of all functions (listed in the System 
Description Document) involving flightcrew interfaces will be 
developed.
    (2) The DER and FAA pilots will use this checklist throughout 
the demonstration and test program to verify that all intended 
functions are satisfactorily implemented.

Appendix D--Information on the Use of Applicant-Conducted Human Factors 
Evaluations, Assessments, and Analyses in Support of Certification

1. What Are the Benefits of Evaluations?

    The FAA recognizes the benefits of early and continuing human 
factors evaluations, assessments, and analyses (from here on 
referred to as ``evaluations'') during the applicant's design 
process. Such evaluations have several potential benefits:
    a. Human factors or flight crew interface problems can be 
identified in a timely manner, so changes can be made with 
acceptable technical, schedule, and economic impacts. This can help 
foster better designs with fewer certification risks and fewer last 
minute design changes. Design changes that are incorporated early 
also are more likely to be well-integrated into the design, rather 
than quick ``patches'' needed to ``plug holes.''
    b. Good aspects of the design can be confirmed early, which can 
increase applicant and FAA confidence. Such confidence, especially 
with respect to human factors issues, can reduce the amount of more 
costly testing (especially flight testing).
    c. Cooperation between the FAA and the applicant on these 
evaluations can give the FAA more overall confidence in the 
applicant's methods and processes with respect to human factors 
issues.
    d. The applicant may choose to conduct evaluations using a 
variety of pilots, with different backgrounds and levels of 
experience. Such tests and evaluations can provide valuable insights 
into how the well the airplane or system will function with line 
pilots.

2. Are Evaluations Required?

    While such human factors evaluations are not required by current 
FAA regulations or advisory material, many applicants routinely 
perform them as part of their normal design development processes. 
The FAA should encourage all applicants to conduct such evaluations, 
when warranted by the nature of the design being developed. This 
policy does not establish any new requirements for such evaluations. 
Instead, the FAA wishes to provide incentives by establishing an 
explicit process by which applicants can use these evaluations to 
reduce certification risk if they choose to do so.

3. Are Evaluations Necessary To Show Compliance?

    These evaluations, in and of themselves, should never be 
considered to be necessary or sufficient to show compliance with the 
regulations. However, in situations where compliance or non-
compliance is not obvious and clear-cut, applicants may wish to use 
such data to support compliance decisions. The FAA personnel should 
take note of the results of evaluations presented for consideration 
by applicants, providing that the FAA agrees the results are 
relevant to the compliance findings.

4. How Should the Evaluations Be Conducted?

    Because these evaluations can take a variety of forms, the FAA 
and the applicant should discuss them fully to understand the 
capabilities and limitations of the evaluations and the conclusions 
that can be drawn from them.
    This policy will not establish a specific set of recommendations 
for these evaluations. The requirements for any specific evaluation 
that an applicant might propose would be influenced by several 
factors, including those listed as follows. The FAA and applicant 
should discuss these factors.
     The level of similarity between the tested flightcrew 
interface (including displays, controls, procedures, system 
performance) and the expected characteristics of the system 
(hardware and software) that will be certified.
     The areas of certification risk related to human 
factors. The design characteristics and the related regulations 
should both be considered.
     The pilots (or others) that will be used in the 
evaluations.
     The types of data that will be collected (objective vs. 
subjective, performance vs. opinion).
     The types of conclusions that the applicant hopes to 
derive, based on the evaluations.

5. When Should the Evaluation Be Planned and Coordinated With the 
FAA?

    It would be desirable for the applicant to identify the types of 
evaluations that will be conducted when certification planning is in 
progress, if the applicant wishes to use such evaluations as part of 
their overall data collection effort in support of certification. 
Applicants should be encouraged to discuss in some detail with the 
FAA the evaluations they are developing. In most cases, it is 
appropriate for FAA personnel to ask for an opportunity to review 
the tested configuration and the test scenarios. This will allow the 
FAA personnel to determine whether the evaluations are appropriate 
and relevant for the compliance issues under consideration.
    However, the FAA recognizes that such evaluations may be 
conceived and planned later during the development cycle. In such 
cases, it is acceptable for the applicant to communicate such plans 
to the FAA as they develop, so that agreement can be reached on the 
appropriateness of the evaluations with respect to certification. If 
the applicant has already developed a certification plan, it may be 
useful to update the certification plan as a way to document the 
intent to use such evaluations.
    Finally, the FAA recognizes that the applicant may collect data 
during evaluations without intending to use the evaluations to 
support certification, but may achieve results that are subsequently 
believed to be relevant to certification. Under these circumstances, 
it is acceptable for the applicant to describe the evaluations to 
the FAA and request consideration of the results, even though the 
evaluations were not part of the certification plans.

6. How Should Evaluation Results Be Interpreted?

    In order for applicants to consider such evaluations to be a way 
to reduce rather than increase certification risk, some latitude in 
interpreting evaluation results must be permitted, especially in 
view of the issues described above.
    For example, the applicant should feel confident collecting and 
then presenting evaluations that include data from subjects who 
experienced difficulties or who provided negative comments on the 
design. Such data should be considered a normal part of such 
development testing, and in some cases, point out the strength and 
value of such testing. In such situations, applicants should be 
given the opportunity to explain causes of the reported problems and 
how the features of the design have been modified to

[[Page 27211]]

account for the problems. Unlike conventional certification testing 
for systems, the applicant should not be expected to repeat the 
evaluations in order to ``prove'' that the problems have been 
mitigated. Rather, the nature of the problems, the explanations, and 
the design modifications can all be used to form the basis for the 
FAA's overall assessment of the results and the relevance of those 
results to certification.

7. Summary

    In summary, this policy is intended to provide an incentive to 
applicants, so that they will conduct effective human factors 
evaluations during the design phase of a program. Involvement of the 
FAA during the design phase is also a desired, but not a required, 
outcome.
    This policy should not be used by FAA personnel to force such 
evaluations as part of the certification process. In other words, 
there should be no penalties, either formal or informal, for an 
applicant who chooses not to use such evaluations as part of their 
certification effort.
    However, if the applicant chooses to submit the results of such 
evaluations, and the FAA agrees that the evaluations were 
appropriate, then the FAA should consider the results of the 
evaluations as part of their overall determination of the amount of 
additional testing (or other methods of compliance) required to show 
compliance with the regulations.
    Applicants should be encouraged to keep the FAA involved. This 
will improve the quality and value of the evaluations (with respect 
to certification), foster FAA confidence in the applicant's 
evaluation methods and processes, and maximize the benefit of the 
evaluations.


    Issued in Renton, Washington, on May 8, 2001.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.

[FR Doc. 01-12275 Filed 5-17-01; 8:45 am]
BILLING CODE 4910-13-U