Special Conditions: Lockheed Martin Aerospace Corp. Model L382J Airplane

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.

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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]

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