[Federal Register Volume 59, Number 78 (Friday, April 22, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-9758]


[[Page Unknown]]

[Federal Register: April 22, 1994]


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Part III





Department of Transportation





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Federal Aviation Administration



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14 CFR Parts 1 and 25




Revision of Certain Flight Airworthiness Standards To Harmonize With 
European Airworthiness Standards for Transport Category Airplanes; 
Proposed Rule and Notice
DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Parts 1 and 25

[Docket No. 27705; Notice No. 94-15]
RIN AF 25

 
Revision of Certain Flight Airworthiness Standards To Harmonize 
With European Airworthiness Standards for Transport Category Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking.

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SUMMARY: The Federal Aviation Administration (FAA) proposes to amend 
part 25 of the Federal Aviation Regulations (FAR) to harmonize certain 
flight requirements with standards proposed for the European Joint 
Aviation Requirements 25 (JAR-25). This action responds to a petition 
from the Aerospace Industries Association of America, Inc. and the 
Association Europeenne des Constructeurs de Materiel Aerospatial. These 
changes are intended to benefit the public interest by standardizing 
certain requirements, concepts, and procedures contained in the 
airworthiness standards of the FAR and the JAR.

DATES: Comments must be received on or before July 21, 1994.

ADDRESSES: Comments on this notice may be mailed in triplicate to: 
Federal Aviation Administration, Office of the Chief Counsel, 
Attention: Rules Docket (AGC-10), Docket No. 27705, 800 Independence 
Avenue SW., Washington, DC 20591; or delivered in triplicate to: Room 
915G, 800 Independence Avenue SW., Washington, DC 20591. Comments 
delivered must be marked Docket No. 27705. Comments may be examined in 
room 915G weekdays, except Federal holidays, between 8:30 a.m. and 5 
p.m. In addition, the FAA is maintaining an information docket of 
comments in the Transport Airplane Directorate (ANM-100), Federal 
Aviation Administration, Northwest Mountain Region, 1601 Lind Avenue 
SW., Renton, WA 98055-4056. Comments in the information docket may be 
examined weekdays, except Federal holidays, between 7:30 a.m. and 4 
p.m.

FOR FURTHER INFORMATION CONTACT:
Donald K. Stimson, Flight Test and Systems Branch, ANM-111, Transport 
Airplane Directorate, Aircraft Certification Service, FAA, 1601 Lind 
Avenue SW., Renton, WA 98055-4056; telephone (206) 227-1129; facsimile 
(206) 227-1320.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in this proposed 
rulemaking by submitting such written data, views, or arguments as they 
may desire. Comments relating to any environmental, energy, or economic 
impact that might result from adopting the proposals contained in this 
notice are invited. Substantive comments should be accompanied by cost 
estimates. Commenters should identify the regulatory docket or notice 
number and submit comments in triplicate to the Rules Docket address 
above. All comments received on or before the closing date for comments 
will be considered by the Administrator before taking action on this 
proposed rulemaking. The proposals contained in this notice may be 
changed in light of comments received. All comments received will be 
available in the Rules Docket, both before and after the comment period 
closing date, for examination by interested persons. A report 
summarizing each substantive public contact with FAA personnel 
concerning this rulemaking will be filed in the docket. Persons wishing 
the FAA to acknowledge receipt of their comments must submit with those 
comments a self-addressed, stamped postcard on which is stated: 
``Comments to Docket No. 27705.'' The postcard will be date stamped and 
returned to the commenter.

Availability of the NPRM

    Any person may obtain a copy of this notice by submitting a request 
to the Federal Aviation Administration (FAA), Office of Public Affairs, 
Attention: Public Inquiry Center, APA-230, 800 Independence Avenue SW., 
Washington, DC 20591; or by calling (202) 267-3484. The notice number 
of this NPRM must be identified in all communications. Persons 
interested in being placed on a mailing list for future rulemaking 
documents should also request a copy of Advisory Circular No. 11-2A, 
Notice of Proposed Rulemaking Distribution System, which describes the 
application procedure.

Background

    Part 25 of the Federal Aviation Regulations (FAR) contains the 
airworthiness standards for transport category airplanes. Manufacturers 
of transport category airplanes must show that each airplane they 
produce of a different type design complies with the relevant standards 
of part 25. These standards apply to airplanes manufactured within the 
U.S. for use by U.S.-registered operators and to airplanes manufactured 
in other countries and imported under a bilateral airworthiness 
agreement.
    In Europe, the Joint Aviation Requirements (JAR) were developed by 
the Joint Aviation Authorities (JAA) to provide a common set of 
airworthiness standards for use within the European aviation community. 
The airworthiness standards for European type certification of 
transport category airplanes, JAR-25, are based on part 25 of the FAR. 
Airplanes certificated to the JAR-25 standards, including airplanes 
manufactured in the U.S. for export to Europe, receive type 
certificates that are accepted by the aircraft certification 
authorities of 23 European countries.
    Although part 25 and JAR-25 are very similar, they are not 
identical. Differences between the FAR and the JAR can result in 
substantial additional costs when airplanes are type certificated to 
both standards. These additional costs, however, do not always bring 
about an increase in safety. For example, part 25 and JAR-25 may use 
different means to accomplish the same safety intent. In this case, the 
manufacturer is usually burdened with meeting both requirements, 
although the level of safety is not increased correspondingly. 
Recognizing that a common set of standards would not only economically 
benefit the aviation industry, but would also maintain the necessary 
high level of safety, the FAA and JAA consider harmonization to be a 
high priority.
    On May 22, 1990, the Aerospace Industries Association of America, 
Inc. (AIA) and the Association Europeenne des Constructeurs de Materiel 
Aerospatial (AECMA) jointly petitioned the FAA and JAA to harmonize 
certain requirements contained in part 25 of the FAR and in JAR-25. In 
their petition, a summary of which was published in the July 17, 1990, 
edition of the Federal Register (55 FR 137), AIA and AECMA requested 
changes to Secs. 25.143(c), 25.143(f), 25.149, and 25.201 to 
standardize the requirements, concepts, and procedures for 
certification flight testing and to enhance reciprocity between the FAA 
and JAA. In addition, AIA and AECMA recommended changes to FAA Advisory 
Circular (AC) 25-7, ``Flight Test Guide for Certification of Transport 
Category Airplanes,'' to ensure that the harmonized standards would be 
interpreted and applied consistently. A copy of that petition is 
included in the docket for this rulemaking.
    On September 26, 1991, the Aviation Rulemaking Advisory Committee 
(ARAC) established the Flight Test Working Group, assigning it the task 
of developing either a draft notice of proposed rulemaking (NPRM) or a 
denial of the AIA/AECMA petition. If accepted by the ARAC, the draft 
NPRM or petition denial would be delivered to the FAA as an advisory 
committee recommendation.
    The public notice establishing the Flight Test Working Group 
appeared in the Federal Register on January 13, 1992 (57 FR 1297). The 
Flight Test Working Group was later renamed the Flight Test 
Harmonization Working Group and its scope was clarified to include 
developing a similar proposal to amend JAR-25, as necessary, to achieve 
harmonization.
    The rulemaking proposal contained in this notice was developed by 
the Flight Test Harmonization Working Group. It was presented to the 
FAA by the ARAC as a recommended response to the AIA/AECMA petition. 
Rather than proposing a simple acceptance or denial of the petition, 
the working group used the petition as a starting point for developing 
a rulemaking proposal that would accomplish the goal of harmonizing not 
only the sections of part 25 and JAR-25 addressed in the petition, but 
also related sections.

The Aviation Rulemaking Advisory Committee

    The ARAC was formally established by the FAA on January 22, 1991 
(56 FR 2190), to provide advice and recommendations concerning the full 
range of the FAA's safety-related rulemaking activity. This advice was 
sought to develop better rules in less overall time using fewer FAA 
resources than are currently needed. The committee provides the 
opportunity for the FAA to obtain firsthand information and insight 
from interested parties regarding proposed new rules or revisions of 
existing rules.
    There are over 60 member organizations on the committee, 
representing a wide range of interests within the aviation community. 
Meetings of the committee are open to the public, except as authorized 
by section 10(d) of the Federal Advisory Committee Act.
    The ARAC establishes working groups to develop proposals to 
recommend to the FAA for resolving specific issues. Tasks assigned to 
working groups are published in the Federal Register. Although working 
group meetings are not generally open to the public, all interested 
parties are invited to participate as working group members. Working 
groups report directly to the ARAC, and the ARAC must concur with a 
working group proposal before that proposal can be presented to the FAA 
as an advisory committee recommendation.
    The activities of the ARAC will not, however, circumvent the public 
rulemaking procedures. After an ARAC recommendation is received and 
found acceptable by the FAA, the agency proceeds with the normal public 
rulemaking procedures. Any ARAC participation in a rulemaking package 
will be fully disclosed in the public docket.

Discussion of the Proposals

    The FAA proposes amending certain sections of the FAR, as 
recommended by the ARAC, to harmonize these sections with JAR-25. The 
JAA intend to publish a Notice of Proposed Amendment (NPA), also 
developed by the Flight Test Harmonization Working Group, to revise 
JAR-25, as necessary, to ensure harmonization in those areas for which 
the proposed amendments differ from the current JAR-25. When it is 
published, the NPA will be placed in the docket for this rulemaking.
    The FAA proposes to: (1) Introduce the term ``go-around power or 
thrust setting'' to clarify certain part 25 flight requirements; (2) 
revise the maximum control forces permitted for demonstrating 
compliance with the controllability and maneuverability requirements; 
(3) provide requirements for stick force and stick force gradient in 
maneuvering flight; (4) revise and clarify the requirements defining 
minimum control speed during approach and landing; (5) clarify the 
procedural and airplane configuration requirements for demonstrating 
stalls and revise the list of acceptable flight characteristics used to 
define the occurrence of stall; and (6) require that stall 
characteristics be demonstrated for turning flight stalls at 
deceleration rates up to 3 knots per second.
    Revisions are also proposed for AC 25-7 to ensure consistent 
application of these proposed revised standards. Public comments 
concerning the revisions to AC 25-7 are invited by separate notice 
published elsewhere in this issue of the Federal Register.

Proposal 1

    Certain part 25 flight requirements involving flight conditions 
other than takeoff (i.e., Secs. 25.119, 25.121(d), 25.145(b)(3), 
25.145(b)(4), 25.145(b)(5), 25.145(c)(1), 25.149(f)(6), and 
25.149(g)(7)(ii)) specify using the maximum available takeoff power or 
thrust as being representative of the appropriate maximum in-flight 
power or thrust. In practice, however, the power or thrust setting used 
to obtain the maximum in-flight power or thrust (commonly referred to 
as the go-around power or thrust setting) usually differs from the 
setting used for takeoff. In the past, the FAA interpreted the words 
``maximum available takeoff power or thrust'' to mean the maximum in-
flight power or thrust, with the takeoff power or thrust setting not 
always being ``available'' in flight. The FAA proposes changing the 
nomenclature to ``go-around power or thrust setting'' for clarity and 
to reflect terminology commonly used in the operational environment. 
(In the context of this discussion, the term ``go-around'' refers to a 
deliberate maneuver to abort a landing attempt prior to touchdown by 
applying the maximum available power or thrust, retracting flaps, and 
climbing to a safe level-off altitude).
    (The go-around power or thrust setting may differ from the takeoff 
power or thrust setting, for example, due to the airspeed difference 
between the takeoff and go-around flight conditions. In addition, 
complying with the powerplant limitations of Sec. 25.1521 may result in 
a lower power setting at the higher airspeeds associated with a go-
around. As another example, the controllability requirements of 
Secs. 25.145(b)(3), 25.145(b)(4), 25.145(b)(5), 25.149(f), and 
25.149(g) may also limit the go-around power or thrust setting to less 
than that used for takeoff. Another reason to separate the takeoff and 
go-around power (or thrust) nomenclature is that certification practice 
has not required, and applicants have not always proposed, changing the 
go-around power or thrust setting when a previously approved takeoff 
power or thrust is increased.
    The FAA proposes to substitute the term ``go-around power or thrust 
setting'' for ``maximum available takeoff power or thrust'' in 
Secs. 25.119, 25.121(d), 25.145(b)(3), 25.145(b)(4), 25.145(c)(1), 
25.149(f)(6), and 25.49(g)(7)(ii). (Note that the requirement of 
Sec. 25.145(b)(5) also uses the power specified in Sec. 25.145(b)(4)). 
In addition, the FAA proposes to define ``go-around power or thrust 
setting'' in part 1 as ``the maximum allowable in-flight power or 
thrust setting identified in the performance data.'' With this 
revision, the FAA would clarify that the applicable controllability 
requirements should be based on the same power or thrust setting used 
to determine the approach and landing climb performance contained in 
the approved Airplane Flight Manual (AFM).
    The proposed terminology refers to a power or thrust ``setting'' 
rather than a power or thrust to make it clear that existing engine 
ratings would be unaffected. The powerplant limitations of Sec. 25.1521 
would continue to apply at the go-around power (or thrust) setting. 
Existing certification practices would also remain the same, including 
the relationship between the power or thrust values used to comply with 
the landing and approach climb requirements of Secs. 25.119 and 
25.121(d). For example, the thrust value used to comply with 
Sec. 25.121(d) may be greater than that used for Sec. 25.119, if the 
operating engine(s) do not reach the maximum allowable in-flight thrust 
by the end of the eight second time period specified in Sec. 25.119.

Proposal 2

    The FAA proposes to revise the table in Sec. 25.143(c) to match the 
control force limits currently provided in JAR 25.143(c). This table 
prescribes the maximum control forces for the controllability and 
maneuverability flight testing required by Secs. 25.143(a) and 
25.143(b). For transient application of the pitch and roll control, the 
revised table would contain more restrictive maximum control force 
limits for those maneuvers in which the pilot might be using one hand 
to operate other controls, relative to those maneuvers in which both 
hands are normally available for applying pitch and roll control. The 
revised table would retain the current control force limits for 
transient application of the yaw control, and for sustained application 
of the pitch, roll, and yaw controls.
    For maneuvers in which only one hand is assumed to be available, 
the FAA proposes to reduce the maximum permissible control forces from 
75 pounds to 50 pounds for pitch control, and from 60 pounds to 25 
pounds for roll control. These lower control forces would be more 
consistent with Sec. 25.145(b), which states that a force of 50 pounds 
for longitudinal (pitch) control is ``representative of the maximum 
temporary force that readily can be applied by one hand.'' In addition 
to adding more restrictive control force limits for maneuvers in which 
only one hand may be available to apply pitch and roll control, the FAA 
proposes to reduce the maximum permissible force for roll control from 
60 pounds to 50 pounds for maneuvers in which the pilot normally has 
both hands available to operate the control.
    The FAA proposes to further revise Sec. 25.143(c) by specifying 
that the table of maximum permissible control forces applies only to 
conventional wheel type controls. This restriction, also specified in 
the current JAR 25.143(c), recognizes that different control force 
limits may be necessary when considering sidestick controllers or other 
types of control systems.
    For clarification, the FAA proposes to replace the terms 
``temporary'' and ``prolonged,'' used in Secs. 25.143(c), 25.143(d), 
25.143(e), and 25.145(b), with ``transient'' and ``sustained,'' 
respectively. ``Transient'' forces refer to those control forces 
resulting from maintaining the intended flight path during changes to 
the airplane configuration, normal transitions from one flight 
condition to another, or regaining control after a failure. The pilot 
is assumed to take immediate action to reduce or eliminate these forces 
by retrimming or by changing the airplane configuration or flight 
condition. ``Sustained forces,'' on the other hand, refer to those 
control forces resulting from normal or failure conditions that cannot 
readily be trimmed out or eliminated. The FAA is proposing to add these 
definitions of ``transient'' and ``sustained'' forces to AC 25-7.
    In addition, the FAA proposes several minor editorial changes for 
Secs. 25.143(c) through 25.143(e) to improve readability and correct 
grammatical errors. For example, the words ``immediately preceding'' 
are proposed to replace ``next preceding'' in Sec. 25.143(d). These 
editorial changes are intended to clarify the existing interpretation 
of the affected sections.

Proposal 3

    The FAA proposes to add the JAR 25.143(f) requirements regarding 
control force characteristics during maneuvering flight to part 25 as a 
new Sec. 25.143(f). By adding these requirements, the FAA would ensure 
that the force to move the control column, or ``stick,'' must not be so 
great as to make excessive demands on the pilot's strength when 
maneuvering the airplane, and must not be so low that the airplane can 
easily be overstressed inadvertently.
    These harmonized requirements would apply up to the speed VFC/
MFC (the maximum speed for stability characteristics) rather than 
the speed VMO/MMO (the maximum operating limit speed) 
specified by the current JAR 25.143(f). Requiring these maneuvering 
requirements to be met up to VFC/MFC is consistent with other 
part 25 stability requirements. Section 25.253, which defines VFC/
MFC, would be revised to reference the use of this speed in the 
proposed Sec. 25.143(f). An acceptable means of compliance with 
Sec. 25.143(f), including detailed interpretations of the stick force 
characteristics that meet these requirements, would be added to AC 25-
7.

Proposal 4

    Section 25.149(f) requires that the minimum control speed be 
determined assuming the critical engine suddenly fails during (or just 
prior to) go-around from an all-engines-operating approach. For 
airplanes with three or more engines, Sec. 25.149(g) requires the 
minimum control speed to be determined for a one-engine-inoperative 
landing approach in which a second critical engine suddenly fails. The 
FAA proposes to revise Secs. 25.149(f) through 25.149(h) to clarify and 
revise the criteria for establishing these minimum control speeds, 
VMCL and VMCL-2, respectively, for use during approach and 
landing.
    The FAA proposes to clarify that VMCL and VMCL-2 apply 
not only to the airplane's approach configuration(s), as prescribed in 
the current standards, but also to the landing configuration(s). The 
FAA recognizes that configuration changes occur during approach and 
landing (e.g., flap setting and landing gear position) and considers 
that the minimum control speeds provided in the AFM should ensure 
airplane controllability, following a sudden engine failure, throughout 
the approach and landing.
    Applicants would have the option of determining VMCL and 
VMCL-2 either for the most critical of the approach and landing 
configurations (i.e., the configuration resulting in the highest 
minimum control speed), or for each configuration used for approach or 
for landing. By determining the minimum control speeds in the most 
critical configuration, applicants would not be required to conduct any 
additional testing to that already required by the current standards. 
Only if these resulting speeds proved too constraining for other 
configurations would the FAA expect applicants to exercise the option 
of testing multiple configurations.
    The FAA also proposes to add provisions to state the position of 
the propeller, for propeller airplanes, when establishing these minimum 
control speeds. For the critical engine that is suddenly made 
inoperative, the propeller position must reflect the most critical mode 
of powerplant failure with respect to controllability, as required by 
Sec. 25.149(a). Also, since credit cannot be given for pilot action to 
feather the propeller during this high flightcrew workload phase of 
flight, the FAA proposes that VMCL and VMCL-2 be determined 
with the propeller position of the most critical engine in the position 
it automatically achieves. For VMCL-2, the engine that is already 
inoperative before beginning the approach may be feathered, since the 
pilot is expected to ensure the propeller is feathered before 
initiating the approach.
    To assure that airplanes have adequate lateral control capability 
at VMCL and VMCL-2, the FAA proposes to require the airplane 
to be capable of rolling, from an initial condition of steady straight 
flight, through an angle of 20 degrees in not more than 5 seconds, in 
the direction necessary to start a turn away from the inoperative 
engine. This proposed addition to Sec. 25.149 is contained in the 
current JAR 25.149.
    The FAA is proposing guidance material for AC 25-7 to enable 
applicants to additionally determine the appropriate minimum control 
speeds for an approach and landing in which one engine, and, for 
airplanes with three or more engines, two engines, are already 
inoperative prior to beginning the approach. These speeds, VMCL(1 
out) and VMCL-2(2 out), would be less restrictive than VMCL 
and VMCL-2 because the pilot is assumed to have trimmed the 
airplane for the approach with an inoperative engine (for VMCL(1 
out)) or two inoperative engines (for VMCL-2(2 out)). Also, the 
approach and landing procedures under these circumstances may use 
different approach and landing flaps than for the situations defining 
VMCL or VMCL-2. These additional speeds can be used as 
guidance in determining the recommended procedures and speeds for a 
one-engine-inoperative, or, in the case of an airplane with three or 
more engines, a two-engine-inoperative approach and landing.
    The FAA proposes to revise Sec. 25.125 to require the approach 
speed used for determining the landing distance to be equal to or 
greater than VMCL, the minimum control speed for approach and 
landing with all-engines-operating. This provision would ensure that 
the speeds used for normal landing approaches with all-engines-
operating would provide satisfactory controllability in the event of a 
sudden engine failure during, or just prior to, a go-around.

Proposal 5

    The FAA proposes to revise the stall demonstration requirements of 
Sec. 25.201 to clarify the airplane configurations and procedures used 
in flight tests to demonstrate stall speeds and stall handling 
characteristics. The list of acceptable flight characteristics used to 
define the occurrence of stall would also be revised. To be consistent 
with current practice, Sec. 25.201(b)(1) would require that stall 
demonstrations also be conducted with deceleration devices (e.g., speed 
brakes) deployed. Additionally, the FAA proposes clarifying the intent 
of Sec. 25.201(b) to cover normal, rather than failure, conditions by 
requiring that stalls need only be demonstrated for the approved 
configurations.
    Section 25.201(c) would be revised to more accurately describe the 
procedures used for demonstrating stall handling characteristics. The 
cross-reference to Sec. 25.103(b), currently contained in 
Sec. 25.201(c)(1), would be moved to a new Sec. 25.201(b)(4) for 
editorial clarity and harmony with the JAR-25 format. Reference to the 
pitch control reaching the aft stop, which would be interpreted as one 
of the indications that the airplane has stalled, would be moved from 
Sec. 25.201(c)(1) to Sec. 25.201(d)(3).
    The list of acceptable flight characteristics that define the 
occurrence of a stall, used during the flight tests demonstrating 
compliance with the stall requirements, is provided in Sec. 25.201(d). 
The FAA proposes to revise this list to conform with current practices. 
Section 25.201(d)(1)(ii) would be removed to clarify that a rolling 
motion, occurring by itself, is not considered an acceptable flight 
characteristic for defining the occurrence of a stall. The proposed 
Sec. 25.201(d)(2) would replace the criteria of Secs. 25.201(d)(1)(iii) 
and 25.201(d)(2) because only deterrent buffeting (i.e., a distinctive 
shaking of the airplane that is a strong and effective deterrent to 
further speed reduction) is considered to comply with those criteria. 
Finally, the proposed Sec. 25.201(d)(3) would define as a stall a 
condition in which the airplane does not continue to pitch up after the 
pitch control has been pulled back as far as it will go and held there 
for a short period of time. Guidance material would be added to AC 25-7 
to define the length of time that the control stick must be held in 
this full aft position when using Sec. 25.201(d)(3) to define a stall.

Proposal 6

    Section 25.201 currently requires stalls to be demonstrated at 
airspeed deceleration rates (i.e., entry rates) not exceeding one knot 
per second. JAR 25.201 currently requires, in addition, that turning 
flight stalls must also be demonstrated at accelerated rates of entry 
into the stall (i.e., dynamic stalls). According to the JAA, the 
intended procedure for demonstrating dynamic stalls begins with a 1 
knot per second deceleration from the trim speed (similar to normal 
stalls). Then, approximately halfway between the trim speed and the 
stall warning speed, the flight test pilot applies the elevator control 
to achieve an increase in the rate of change of angle-of-attack. The 
final angle-of-attack rate and the control input to achieve it should 
be appropriate to the type of airplane and its particular control 
characteristics.
    The AIA/AECMA petition detailed various difficulties with 
interpretation of the JAR-25 requirement, noted that the requirement is 
not contained in the FAR, and proposed that dynamic stalls be removed 
from JAR-25. Some of the concerns with the JAR-25 dynamic stall 
requirement include: (1) A significant number of flight test 
demonstrations for compliance used inappropriate piloting techniques 
considering the capabilities of transport category airplanes; (2) the 
stated test procedures depend, to a large extent, on pilot 
interpretation, resulting in test demonstrations that could vary 
significantly for different test pilots; (3) the safety objective of 
the requirement is not well understood within the aviation community; 
and (4) the flight test procedures that are provided are inconsistent 
with the flight characteristics being evaluated. As a result, 
applicants are unable to ensure that their designs will comply with the 
JAR-25 dynamic stall requirement prior to the certification flight 
test.
    In practice, FAA certification testing has typically included stall 
demonstrations at entry rates higher than 1 knot per second. For 
airplanes with certain special features, such as systems designed to 
prevent a stall or that are needed to provide an acceptable stall 
indication, higher entry rates are demonstrated to show that the system 
will continue to safely perform its intended function under such 
conditions. These higher entry rate stalls are different, however, from 
the JAR-25 dynamic stalls.
    Rather than simply deleting the dynamic stall requirement from JAR-
25, or adding this requirement to part 25 of the FAR, the ARAC 
recommended harmonizing the two standards by requiring turning flight 
stalls be demonstrated at steady airspeed deceleration rates up to 3 
knots per second. The FAA agrees with this recommendation and proposes 
to add the requirement for a higher entry rate stall demonstration to 
part 25 as Sec. 25.201(c)(2). The current Sec. 25.201(c)(2) would be 
redesignated Sec. 25.201(c)(3). The JAA is proposing to replace the 
JAR-25 dynamic stall requirement with the ARAC recommendation.
    The proposed higher entry rate stall demonstration is a controlled 
and repeatable maneuver that meets the objective of evaluating stall 
characteristics over a range of entry conditions that might reasonably 
be encountered by transport category airplanes in operational service. 
Some degradation in characteristics would be accepted at the higher 
entry rates, as long as it does not present a major threat to recovery 
from the point at which the pilot has recognized the stall. Guidance 
material is being proposed for AC 25-7 to point out that the specified 
deceleration rate, and associated rate of increase in angle of attack, 
should be established from the trim speed specified in 
Sec. 25.103(b)(1) and maintained up to the point at which the airplane 
stalls.
    The FAA proposes to revise Sec. 25.203(c) to specify a bank angle 
that must not be exceeded during the recovery from the turning flight 
stall demonstrations. Currently, Sec. 25.203(c) provides only a 
qualitative statement that a prompt recovery must be easily attainable 
using normal piloting skill. By specifying a maximum bank angle limit, 
the FAA proposes to augment this qualitative requirement with a 
quantitative one.
    For deceleration rates up to 1 knot per second, the maximum bank 
angle would be approximately 60 degrees in the original direction of 
the turn, or 30 degrees in the opposite direction. These bank angle 
limits are currently contained in JAR-25 guidance material, and have 
been used informally during FAA certification programs as well. For 
deceleration rates higher than 1 knot per second, the FAA proposes to 
allow a greater maximum bank angle--approximately 90 degrees in the 
original direction of the turn, or 60 degrees in the opposite 
direction. These are the same acceptance criteria currently used by the 
JAA to evaluate dynamic stall demonstrations.
    In addition to the amendments to part 25 proposed in this notice, 
revisions to AC 25-7 are being proposed to ensure that the harmonized 
standards would be interpreted and applied consistently. AC 25-7 
provides guidelines that the FAA has found acceptable regarding flight 
testing transport category airplanes to demonstrate compliance with the 
applicable airworthiness requirements. Public comments concerning the 
proposed revisions to AC 25-7 are invited by separate notice published 
elsewhere in this issue of the Federal Register.

Regulatory Evaluation Summary

Preliminary Regulatory Evaluation, Initial Regulatory Flexibility 
Determination, and Trade Impact Assessment

    Proposed changes to Federal regulations must undergo several 
economic analyses. First, Executive Order 12866 directs that each 
Federal agency shall propose or adopt a regulation only upon a reasoned 
determination that the benefits of the intended regulation justify its 
costs. Second, the Regulatory Flexibility Act of 1980 requires agencies 
to analyze the economic effect of the regulatory changes on small 
entities. Third, the Office of Management and Budget directs agencies 
to assess the effects of regulatory changes on international trade. In 
conducting these analyses, the FAA has determined that this rule: (1) 
Would generate benefits that justify its costs and is not a 
``significant regulatory action'' as defined in the Executive Order; 
(2) is not significant as defined in DOT's Policies and Procedures; (3) 
would not have a significant impact on a substantial number of small 
entities; and (4) would not constitute a barrier to international 
trade. These analyses, available in the docket, are summarized below.

Cost Benefit Analysis

    Three of the proposed 48 revisions to the flight test airworthiness 
standards of part 25 would require additional flight testing and 
engineering analysis, resulting in compliance costs of $18,500 per type 
certification. When amortized over a representative production run of 
500 airplanes, this total cost would result in a negligible incremental 
cost of $37 per airplane. The FAA solicits comments concerning the 
incremental flight test certification costs attributable to the 
proposed rule.
    The primary benefits of the proposed rule would be harmonization of 
flight test airworthiness standards with the European Joint Aviation 
Requirements and clarification of existing standards. The resulting 
increased uniformity of flight test standards would simplify 
airworthiness approval for import and export purposes and would avoid 
some of the costs that can result when manufacturers seek type 
certification under both sets of standards. While not readily 
quantifiable, the potential cost avoidance would exceed the relatively 
minor incremental costs of the proposed rule.
    The proposed rule would provide additional benefits by updating 
certain airworthiness standards. These updated standards would adopt 
terminology commonly used in airplane operations as well as better 
reflect current flight test practices.

Regulatory Flexibility Determination

    The Regulatory Flexibility Act of 1980 (RFA) was enacted by 
Congress to ensure that small entities are not unnecessarily or 
disproportionately burdened by Federal regulations. The RFA requires a 
Regulatory Flexibility Analysis if a proposed rule would have a 
significant economic impact, either detrimental or beneficial, on a 
substantial number of small entities. Based on FAA Order 2100.14A, 
Regulatory Flexibility Criteria and Guidance, the FAA has determined 
that the proposed amendments would not have a significant economic 
impact on a substantial number of small entities.

Trade Impact Assessment

    The proposed rule would not constitute a barrier to international 
trade, including the export of American airplanes to foreign countries, 
and the import of foreign airplanes into the United States. Instead, 
the proposed flight testing standards have been harmonized with those 
of foreign aviation authorities, thereby lessening restraints on trade.

Federalism Implications

    The amended regulations proposed in this rulemaking would not have 
substantial direct effects on the States, on the relationship between 
the national government and the States, or on the distribution of power 
and responsibilities among the various levels of government. Therefore, 
in accordance with Executive Order 12612, it is determined that this 
proposal would not have sufficient federalism implications to warrant 
preparing a Federalism Assessment.

Conclusion

    Because the proposed changes to standardize specific flight 
requirements of part 25 of the FAR are not expected to result in 
substantial economic cost, the FAA has determined that this proposed 
regulation would not be significant under Executive Order 12866. 
Because this is an issue which has not prompted a great deal of public 
concern, the FAA has determined that this action is not significant 
under DOT Regulatory Policies and Procedures (44 FR 11034, February 25, 
1979). In addition since there are no small entities affected by this 
proposed rulemaking, the FAA certifies, under the criteria of the 
Regulatory Flexibility Act, that this rule, if adopted, will not have a 
significant economic impact, positive or negative, on a substantial 
number of small entities. An initial regulatory evaluation of the 
proposal, including a Regulatory Flexibility Determination and Trade 
Impact Analysis, has been placed in the docket. A copy may be obtained 
by contacting the person identified under FOR FURTHER INFORMATION 
CONTACT.

List of Subjects

14 CFR Part 1

    Air transportation.

14 CFR Part 25

    Aircraft, Aviation safety, Reporting and recordkeeping 
requirements.

The Proposed Amendments

    Accordingly, the Federal Aviation Administration (FAA) proposed to 
amend 14 CFR parts 1 and 25 of the Federal Aviation Regulations (FAR) 
as follows:

PART 1--DEFINITIONS AND ABBREVIATIONS

    1. The authority citation for part 1 continues to read as follows:

    Authority: 49 U.S.C. app. 1347, 1348, 1354(a), 1357(d)(2), 1372, 
1421 through 1430, 1432, 1442, 1443, 1472, 1510, 1522, 1652(e), 
1655(c), 1657(f), and 49 U.S.C. 106(g).

    2. Section 1.1 is amended by adding a new definition to read as 
follows:


Sec. 1.1  General definitions.

* * * * *
    ``Go-around power or thrust setting'' means the maximum allowable 
in-flight power or thrust setting identified in the performance data.
* * * * *

PART 25--AIRWORTHINESS STANDARDS--TRANSPORT CATEGORY AIRPLANES

    3. The authority citation for part 25 continues to read as follows:

    Authority: 49 U.S.C. app. 1344, 1354(a), 1355, 1421, 1423, 1424, 
1425, 1428, 1429, 1430; 49 U.S.C. 106(g); and 49 CFR 1.47(a).

    4. Section 25.119 is amended by revising paragraph (a) to read as 
follows:


Sec. 25.119  Landing climb: All-engines-operating.

* * * * *
    (a) The engines at the power or thrust that is available eight 
seconds after initiation of movement of the power or thrust controls 
from minimum flight idle to the go-around power or thrust setting; and
* * * * *
    5. Section 25.121 is amended by revising paragraph (d)(1) to read 
as follows:


Sec. 25.121  Climb: One-engine-inoperative.

* * * * *
    (d) * * *
    (1) The critical engine inoperative, the remaining engines at the 
go-around power or thrust setting;
* * * * *
    6. Section 25.125 is amended by revising paragraph (a)(2) to read 
as follows:


Sec. 25.125  Landing.

* * * * *
    (a) * * *
    (2) A stabilized approach, with a calibrated airspeed of not less 
than 1.3 VS or VMCL, must be maintained down to the 50 foot 
height.
* * * * *
    7. Section 25.143 is amended by revising paragraphs (c), (d), and 
(e) and adding a new paragraph (f) to read as follows:


Sec. 25.143  General.

* * * * *
    (c) The following table prescribes, for conventional wheel type 
controls, the maximum control forces permitted during the testing 
required by paragraphs (a) and (b) of this section:

------------------------------------------------------------------------
 Force, in pounds, applied to the control wheel                         
                or rudder pedals                   Pitch    Roll    Yaw 
------------------------------------------------------------------------
For transient application for pitch and roll                            
 control--two hands available for control.......       75      50       
For transient application for pitch and roll                            
 control--one hand available for control........       50      25       
For transient application for yaw control.......  .......  ......    150
For sustained application.......................       10       5     20
------------------------------------------------------------------------

    (d) Approved operating procedures or conventional operating 
practices must be followed when demonstrating compliance with the 
control force limitations for transient application that are prescribed 
in paragraph (c) of this section. The airplane must be in trim, or as 
near to being in trim as practical, in the immediately preceding steady 
flight condition. For the takeoff condition, the airplane must be 
trimmed according to the approved operating procedures.
    (e) When demonstrating compliance with the control force 
limitations for sustained application that are prescribed in paragraph 
(c) of this section, the airplane must be in trim, or as near to being 
in trim as practical.
    (f) When maneuvering at a constant airspeed or Mach number (up to 
VFC/MFC), the stick forces and the gradient of the stick 
force versus maneuvering load factor must lie within satisfactory 
limits. The stick forces must not be so great as to make excessive 
demands on the pilot's strength when maneuvering the airplane, and must 
not be so low that the airplane can easily be overstressed 
inadvertently. Changes of gradient that occur with changes of load 
factor must not cause undue difficulty in maintaining control of the 
airplane, and local gradients must not be so low as to result in a 
danger of overcontrolling.
    8. Section 25.145 is amended by revising the introductory text of 
paragraph (b), and paragraphs (b)(3), (b)(4), and (c)(1) to read as 
follows:


Sec. 25.145  Longitudinal control.

* * * * *
    (b) With the landing gear extended, no change in trim control, or 
exertion of more than 50 pounds control force (representative of the 
maximum transient force that can be applied readily by one hand) may be 
required for the following maneuvers:
* * * * *
    (3) Repeat paragraph (b)(2) except at the go-around power or thrust 
setting.
    (4) With power off, flaps retracted, and the airplane trimmed at 
1.4 VS2, rapidly set go-around power or thrust while maintaining 
the same airspeed.


  (4) WITH POWER OFF, FLAPS RETRACTED, AND THE AIRPLANE TRIMMED AT 
         1.4 VS1, RAPIDLY SET GO-AROUND POWER OR THRUST WHILE 
                                     MAINTAINING THE SAME AIRSPEED.

* * * * *
    (c) * * *
    (1) Simultaneous movement of the power or thrust controls to the 
go-around power or thrust setting;
* * * * *
    9. Section 25.149 is amended by revising paragraphs (f), (g) and 
(h) to read as follows:


Sec. 25.149  Minimum Control Speed.

* * * * *
    (f) VMCL, the minimum control speed during approach and 
landing with all engines operating, is the calibrated airspeed at 
which, when the critical engine is suddenly made inoperative, it is 
possible to maintain control of the airplane with that engine still 
inoperative, and maintain straight flight with an angle of bank of not 
more than 5 degrees. VMCL must be established with--
    (1) The airplane in the most critical configuration (or, at the 
option of the applicant, each configuration) for approach and landing 
with all engines operating;
    (2) The most unfavorable center of gravity;
    (3) The airplane trimmed for approach with all engines operating;
    (4) The most unfavorable weight, or, at the option of the 
applicant, as a function of weight;
    (5) The propeller of the inoperative engine, if applicable, in the 
position it automatically achieves; and
    (6) Go-around power or thrust setting on the operating engine(s).
    (g) For airplanes with three or more engines, VMCL-2, the 
minimum control speed during approach and landing with one critical 
engine inoperative, is the calibrated airspeed at which, when a second 
critical engine is suddenly made inoperative, it is possible to 
maintain control of the airplane with both engines still inoperative, 
and maintain straight flight with an angle of bank of not more than 5 
degrees. VMCL-2 must be established with--
    (1) The airplane in the most critical configuration (or, at the 
option of the applicant, each configuration) for approach and landing 
with one critical engine inoperative;
    (2) The most unfavorable center of gravity;
    (3) The airplane trimmed for approach with one critical engine 
inoperative;
    (4) The most unfavorable weight, or, at the option of the 
applicant, as a function of weight;
    (5) If applicable, the propeller of the more critical engine in the 
position it automatically achieves and the propeller of the other 
inoperative engine feathered;
    (6) The power or thrust on the operating engine(s) necessary to 
maintain an approach path angle of 3 degrees when one critical engine 
is inoperative; and
    (7) The power or thrust on the operating engine(s) rapidly changed, 
immediately after the second critical engine is made inoperative, from 
the power or thrust prescribed in paragraph (g)(6) of this section to--
    (i) Minimum power or thrust; and
    (ii) Go-around power or thrust setting.
    (h) In demonstrations of VMCL and VMCL-2--
    (1) The rudder force may not exceed 150 pounds;
    (2) The airplane may not exhibit hazardous flight characteristics 
or require exceptional piloting skill, alertness, or strength;
    (3) Lateral control must be sufficient to roll the airplane, from 
an initial condition of steady straight flight, through an angle of 20 
degrees in the direction necessary to initiate a turn away from the 
inoperative engine(s), in not more than 5 seconds; and
    (4) For propeller airplanes, hazardous flight characteristics must 
not be exhibited due to any propeller position achieved when the engine 
fails or during any likely subsequent movements of the engine or 
propeller controls.
    10. Section 25.201 is amended by revising paragraphs (b), (c), and 
(d) to read as follows:


Sec. 25.201  Stall demonstration.

* * * * *
    (b) In each condition required by paragraph (a) of this section, it 
must be possible to meet the applicable requirements of Sec. 25.203 
with--
    (1) Flaps, landing gear, and deceleration devices in any likely 
combination of positions approved for operation;
    (2) Representative weights within the range for which certification 
is requested;
    (3) The most adverse center of gravity for recovery; and
    (4) The airplane trimmed for straight flight at the speed 
prescribed in Sec. 25.103(b)(1).
    (c) The following procedures must be used to show compliance with 
Sec. 25.203:
    (1) Starting at a speed sufficiently above the stalling speed to 
ensure that a steady rate of speed reduction can be established, apply 
the longitudinal control so that the speed reduction does not exceed 
one knot per second until the airplane is stalled.
    (2) In addition, for turning flight stalls, apply the longitudinal 
control to achieve airspeed deceleration rates up to 3 knots per 
second.
    (3) As soon as the airplane is stalled, recover by normal recovery 
techniques.
    (d) The airplane is considered stalled when the behavior of the 
airplane gives the pilot a clear and distinctive indication of an 
acceptable nature that the airplane is stalled. Acceptable indications 
of a stall, occurring either individually or in combination, are--
    (1) A nose-down pitch that cannot be readily arrested, which may be 
accompanied by a rolling motion that is not immediately controllable 
(provided that the rolling motion complies with Sec. 25.203 (b) or (c) 
as appropriate);
    (2) Buffeting, of a magnitude and severity that is a strong and 
effective deterrent to further speed reduction; or
    (3) The pitch control reaches the aft stop and no further increase 
in pitch attitude occurs when the control is held full aft for a short 
time before recovery is initiated.
    11. Section 25.203 is amended by revising paragraph (c) to read as 
follows:


Sec. 25.203  Stall characteristics.

* * * * *
    (c) For turning flight stalls, the action of the airplane after the 
stall may not be so violent or extreme as to make it difficult, with 
normal piloting skill, to effect a prompt recovery and to regain 
control of the airplane. The maximum bank angle that occurs during the 
recovery may not exceed--
    (1) Approximately 60 degrees in the original direction of the turn, 
or 30 degrees in the opposite direction, for deceleration rates up to 1 
knot per second; and
    (2) Approximately 90 degrees in the original direction of the turn, 
or 60 degrees in the opposite direction, for deceleration rates in 
excess of 1 knot per second.
    12. Section 25.253 is amended by revising paragraph (b) to read as 
follows:


Sec. 25.253  High-speed characteristics.

* * * * *
    (b) Maximum speed for stability characteristics, VFC/MCF. 
VFC/MFC is the maximum speed at which the requirements of 
Secs. 25.143(f), 25.147(e), 25.175(b)(1), 25.177, and 25.181 must be 
met with flaps and landing gear retracted. It may not be less than a 
speed midway between VMO/MMO and VDF/MDF, except 
that, for altitudes where Mach number is the limiting factor, MFC 
need not exceed the Mach number at which effective speed warning 
occurs.

    Issued in Washington, DC, on April 11, 1994.
Thomas E. McSweeny,
Director, Aircraft Certification Service.
[FR Doc. 94-9758 Filed 4-21-94; 8:45 am]
BILLING CODE 4910-13-M