[Federal Register Volume 61, Number 181 (Tuesday, September 17, 1996)]
[Proposed Rules]
[Pages 48862-48864]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-23815]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM-132, Notice No. SC-96-5-NM]


Special Conditions: Lockheed Martin Aerospace Corp. Model L382J 
Airplane

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed special conditions.

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SUMMARY: This document proposes special conditions for the Lockheed 
Martin Aerospace Corp. Model L382J airplane. This airplane will have a 
novel or unusual design feature(s) associated with the installation of 
a dual head up display (HUD) to be used as a primary flight display 
(PFD) for all regimes of normal operation. The HUD will satisfy the 
basic requirements of Sec. 25.1321 and serve as the primary source of 
flight director command information. This document contains the 
additional safety standards which the Administrator considers necessary 
to establish a level of safety equivalent to that established by the 
airworthiness standards of Part 25 of the federal Aviation Regulations 
(FAR).

DATES: Comments must be received on or before November 1, 1996.

ADDRESSES: Comments on this proposal may be mailed in duplicate to: 
Federal Aviation Administration, Office of the Assistant Chief Counsel, 
Attention: Rules Docket (ANM-7), Docket No. NM-132, 1601 Lind Avenue 
SW, Renton, Washington 98055-4056; or delivered in duplicate to the 
Office of the Assistant Chief Counsel at the above address. Comments 
must be marked: Docket No. NM-132. Comments may be inspected in the 
Rules Docket weekdays, except Federal holidays, between 7:30 a.m. and 
4:00 p.m.

FOR FURTHER INFORMATION CONTACT:
Dale Dunford, FAA, Flight Test and Systems Branch, ANM-111, Transport 
Standards Staff, Transport Airplane Directorate, Aircraft Certification 
Service, 1601 Lind Avenue SW, Renton, Washington, 98055-4056; telephone 
206-227-2239.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    Interested persons are invited to participate in the making of 
these proposed special conditions by submitting such written data, 
views, or augments as they may desire. Communications should identify 
the regulatory docket or notice number and be submitted in duplicate to 
the address specified above. All communications received on or before 
the closing date for comments will be considered by the Administrator 
before further rulemaking action on this proposal is taken. The 
proposals contained in this notice may be changed in light of the 
comments received. All comments received will be available, both before 
and after the closing date for comments, in the Rules Docket for 
examination by interested parties. A report summarizing each 
substantive public contact with FAA personnel concerning this 
rulemaking will be filed in the docket. Commenters wishing the FAA to 
acknowledge receipt of their comments submitted in response to this 
notice must include a self-addressed, stamped postcard on which the 
following statement is made: ``Comments to Docket No. NM-132.'' The 
postcard will be date/time stamped and returned to the commenter.

[[Page 48863]]

Background

    On August 2, 1992, Lockheed Martin Aerospace Co. applied for an 
amendment to their Type Certificate No. A1SO to include their new Model 
L382J. The Model L382J is a derivative of the L382B/E/G currently 
approved under Type Certificate No. A1SO, and features a new engine 
(with approximately the same rated horsepower, but heavily flat-rated) 
and propeller, both of which are controlled by a full authority digital 
engine control. Additionally, the flight deck is substantially modified 
by the installation of four liquid crystal flight displays, dual head-
up displays, and Mil-Std 1553 data buses. The flight engineer position 
is deleted, requiring automation of some functions as well as redesign 
of the front and overhead panels. Some structure has been modified but 
the aerodynamics of the airplane are essentially unchanged. The latest 
part 25 requirement will be used for all significantly modified 
portions of the Model 382J (as compared to the present L382), and, for 
the unmodified portions of the airplane, the applicable certification 
standard will be the Part 25 rules that were effective on February 1, 
1965.
    The existing rule, Sec. 25.1321, did not anticipate the design 
features, symbology, chromatic limitations, and pilot view constraints 
associated with most HUDs. This particular HUD application is the first 
attempt to qualify the HUD as a PFD. Current head down displays (HDD) 
provide all primary and other information without requiring the 
flightcrew to transition from one lighting and information display 
format to another and are very tolerant of pilot head position 
regarding acquiring primary flight data. This HUD application would 
require the flight crewmember using the HUD to limit head position in 
order to ensure the ability to acquire the necessary flight information 
and to frequently transition to a different lighting condition and 
display format to acquire flight mode and navigation information. These 
proposed special conditions provide all the necessary requirements to 
determine acceptability of the HUD as a PFD. A proof of concept effort 
is required to substantiate that for the particular application there 
are no unsafe features.

Type Certification Basis

    Under the provisions of Sec. 21.101, Lockheed Martin Aerospace 
Corp. must show that the Model L382J meets the applicable provisions of 
the regulations incorporated by reference in Type Certificate No. A1SO 
or the applicable regulations in effect on the date of application for 
the changes to the Model L382. In addition, the certification basis 
includes certain special conditions and later amended sections of Part 
25 that are not relevant to these proposed special conditions.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., Part 25 as amended) do not contain adequate or 
appropriate safety standards for the Model L382J because of a novel or 
unusual design feature, special conditions are prescribed under the 
provisions of Sec. 21.16.
    Special conditions, as appropriate, are issued in accordance with 
Sec. 11.49 of the FAR after public notice, as required by Secs. 11.28 
and 11.29(b), and become part of the type certification basis in 
accordance with Sec. 21.101(b)(2).
    Special conditions are initially applicable to the model for which 
they are issued. Should the type certificate for that model be amended 
later to include any other model that incorporates the same novel or 
unusual design feature, the special conditions would also apply to the 
other model under the provisions of Sec. 21.101(a)(1).

Novel or Unusual Design Features

    The Model L382J will incorporate a novel or unusual design feature 
which is a dual head up display of primary flight information in a 
monochromatic format using appropriate symbology that may be different 
from similar information provided in the head down display.
    As discussed above, these special conditions are applicable to the 
L382J. Should Lockheed Martin Aerospace Corp. apply at a later date for 
a change to the type certificate to include another model incorporating 
the same novel or unusual design feature, the special conditions would 
apply to that model as well under the provisions of Sec. 21.101(a)(1).

Conclusion

    This action affects only certain novel or unusual design features 
on one model of airplanes. It is not a rule of general applicability, 
and it affects only the manufacturer who applied to the FAA for 
approval of these features on the airplane.

List of Subjects in 14 CFR Part 25

    Air Transportation, Aircraft, Aviation safety, Safety.

    The authority citation for these special conditions is as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701-44702, 44704.

The Proposed Special Conditions

    Accordingly, the Federal Aviation Administration (FAA) proposes the 
following special conditions as part of the type certification basis 
for the Lockheed Martin Aerospace Corp. L382J airplanes.

1. Display Requirements

    a. The HUD must provide adequate information to permit rapid 
evaluation of the airplane's flight state and position during all 
phases of flight. This must be shown to be adequate for manually 
controlling the airplane, and for monitoring the performance of the 
automatic flight control system. The monochrome HUD must be 
compliant with the display criteria contained in Advisory Circular 
25-11, except for the color criteria. Demonstration of the HUD 
system adequacy for manually controlling the airplane shall be in 
accordance with the methodology outlined in the FAA Handling 
Qualities Rating Method (HQRM). This demonstration requirement is 
extended to all HUD display formats, unless use of specific formats 
is prohibited for specific phases of flight.
    b. Symbols must appear clean-shaped, clear, and explicit. Lines 
must be narrow, sharp-edged, and without halo or aliasing. Symbols 
must be stable with no discernible flicker or jitter.
    c. For all phases of flight, the HUD must update the positions 
and motions of primary control symbols with sufficient rates and 
latencies to support satisfactory manual control performance.
    d. The HUD display must present all information in a clear and 
unambiguous manner. Display clutter must be minimized. The HUD 
symbology must not excessively interfere with pilots' forward view, 
ability to visually maneuver the airplane, acquire opposing traffic, 
and see the runway environment. Some data elements of primary flight 
displays are essential or critical, and must not be removed by an 
declutter function. Changes in the display format and primary flight 
data arrangement should be minimized to prevent confusion and to 
enhance the pilots' ability to interpret vital data.
    e. The arrangement and format of the information must be 
sufficiently compatible with the head down displays to preclude 
pilot confusion, misinterpretation, or excessive cognitive workload. 
Immediate transition between the two displays, whether required by 
navigation duties, failure conditions, unusual airplane attitudes, 
or other reasons, must not present difficulties in data 
interpretation or delays/interruptions in the crew's ability to 
manually control the airplane or to monitor the automatic flight 
controls system.
    f. If a wind shear detection system, a ground proximity warning 
system (GPWS), or a traffic alert and collision avoidance system 
(TCAS), as installed, the guidance, warnings, and annunciations 
required to be a part of these systems, and normally required to be 
in the pilot's primary field of view, must be displayed on the HUD.
    g. The HUD display must be demonstrated to be adequate for 
airplane recovery from

[[Page 48864]]

unusual attitudes. This capability must be shown for all foreseeable 
modes of upset, including crew mishandling, autopilot failure 
(including ``slowovers''), and turbulence/gust encounters.

2. Installation Requirements

    a. The arrangement of HUD display controls must be visible to 
and within reach of the pilot from any normal seated position. The 
position and movement of the controls must not lead to inadvertent 
operation. The HUD controls must be adequately illuminated for all 
normal background lighting conditions, and must not create any 
objectionable reflections on the HUD or other flight instruments.
    b. The display brightness must be satisfactory in the presence 
of dynamically changing background (ambient) lighting conditions. If 
automatic control is not provided, it must be shown that a single 
setting is satisfactory. When the brightness level is altered, the 
relative luminance of each displayed symbol, character, or data 
shall vary smoothly. In no case shall any selectable brightness 
level allow any information to be invisible while other data remains 
discernible. There shall be no objectionable brightness transients 
when transitioning between manual and automatic control. The HUD 
data shall be visible in lighting conditions from 0 fL to 10,000 fL. 
If certain lighting conditions prevent the crew to adequately seeing 
and interpreting HUD data (for example, flying directly toward the 
sun), accommodation must be provided to permit the crew to make a 
ready transition to the head down displays.
    c. To the greatest extent practicable, the HUD controls must be 
integrated with other controls, including the flight director, to 
minimize the crew workload associated with HUD operation and to 
ensure flightcrew awareness of engaged flight guidance modes.
    d. The installation of the HUD system must not interfere or 
restrict other installed equipment such as emergency oxygen masks, 
headsets, or microphones. The installation of the HUD must not 
adversely affect the emergency egress provisions for the flightcrew, 
or significantly interfere with crew access. The system also must 
not hinder the crew's movement while conducting any flight 
procedures.
    e. The installation of the HUD system must not present the crew 
with any objectionable glare or reflection in any lighting 
conditions. This is equally applicable from glare or reflections 
visible on the HUD system itself, or that originating from the HUD 
system and visible in other ares such as the windshield. The 
installation of the HUD system must not significantly obstruct 
either pilot's external field of view when both combiners are 
deployed. The external view requirements of Sec. 25.773 must be 
retained with both combiners deployed.
    f. The HUD system must be designed and installed to prevent the 
possibility of pilot injury in the event of an accident or any other 
foreseeable circumstance such as turbulence encounter, hard landing, 
bird strike, etc. The installation of the HUD, including overhead 
unit and combiner, must comply with the head injury criteria of 
Sec. 25.562, Amendment 25-64.
    g. The design eyebox shall be centered around each pilot's 
design eye position, and must be large enough that the minimum 
monocular field of view is visible at the following minimum 
displacements from the cockpit Design Eye Position:

Lateral: 1.5 inches left and right
Vertical: 1.0 inches up and down
Longitudinal: 2.0 inches fore and aft

    These requirements must be met for pilots from 5'2'' to 6'3'' 
tall, while seated with seat belts fastened and with the pilot 
positioned at the design eye position (ref. Sec. 25.777(c)). Larger 
eyebox dimensions may be required for meeting operational 
requirements for use as a full time primary flight display.
    h. The HUD system combiner must not create any objectionable 
distortion of the pilot's external view. The optical qualities 
(accommodation, luminance, vergence) of the HUD shall be uniform 
across the entire field of view. When viewed by both eyes from any 
off-center position within the eyebox, non-uniformities shall not 
produce perceivable differences in binocular view. Notwithstanding 
compliance with these minimum eyebox dimensions, the HUD eyebox must 
be large enough to adequately serve as a primary flight display 
without inducing adverse effects on pilot vision and fatigue.

3. System Requirements

    a. The HUD system must be shown to perform its intended function 
as a primary flight display during all phases of flight. The normal 
operation of the HUD system cannot adversely affect, or be adversely 
affected by other airplane systems. Malfunctions of the HUD system 
which cause loss of all primary flight displays, including both HUDs 
and HDDs, shall be extremely improbable.
    b. The criticality of the HUD system's function to display 
flight and navigation data, including the potential to display 
hazardously misleading information, must be assessed according to 
Secs. 25.1309 and 25.1333, Advisory Circular (AC) 25-11 paragraph 
4.a., and AC 25.1309-1A. All alleviating flightcrew actions that are 
considered in the HUD safety analysis must be validated during 
testing for incorporation in the airplane flight manual procedures 
section or for inclusion in type-specific training.
    c. Since the display of hazardously misleading information on 
more than one primary flight display must be extremely improbable, 
HUD system software shall be developed to Level A requirements, as 
specified by RTCA Document DO-178B, ``Software Considerations in 
Airborne Systems and Equipment Certification.''
    d. The HUD system must monitor the position of the combiner and 
provide a warning to the crew when the combiner position is such 
that conformal symbols will be hazardously misaligned.
    e. The HUD system must be shown adequate for airplane control 
and guidance during an engine failure any phase of flight.
    f. There must be no adverse physiological effects of long term 
use of the HUD system, such as fatigue or eye strain, that cause the 
pilot to have to revert to the HDD. Use of the HUD system also 
cannot require excessive cognitive workload or unreasonable 
limitations on head position.
    g. The current mode of the flight guidance/automatic flight 
control system, shall be clearly annunciated in the HUD unless there 
are compensating features.
    i. The HUD system must be shown to comply with the high 
intensity radiated fields certification requirements specified in 
another special condition, not yet finalized.

    Issued in Renton, Washington, on September 9, 1996.
James V. Devany,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service, ANM-100.
[FR Doc. 96-23815 Filed 9-16-96; 8:45 am]
BILLING CODE 4910-13-M