[Federal Register Volume 63, Number 9 (Wednesday, January 14, 1998)]
[Proposed Rules]
[Pages 2186-2188]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-864]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM145; Notice No. 25-98-01-SC]


Special Conditions: Lockheed-Martin Model 382J, Automatic Thrust 
Control System

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed special conditions.

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SUMMARY: This notice proposes special conditions for the Lockheed-
Martin Model 382J airplane. This airplane will have a novel or unusual 
design feature associated with an automatic thrust control system. The 
applicable airworthiness regulations do not contain adequate or 
appropriate safety standards for this design feature. These proposed 
special conditions contain the additional safety standards that the 
Administrator considers necessary to establish a level of safety 
equivalent to that established by the existing airworthiness standards.

DATES: Comments must be received on or before March 2, 1998.

ADDRESSES: Comments on this proposal may be mailed in duplicate to: 
Federal Aviation Administration, Office of the Assistant Chief Counsel, 
Attention: Rules Docket (ANN-7), Docket No. NM145, 1601 Lind Avenue SW, 
Renton, Washington 98055-4056; or delivered in duplicate to the Office 
of the Assistant

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Chief Counsel at the above address. Comments must be marked: Docket No. 
NM145. 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: Connie Beane, FAA, Standardization 
Branch, ANM-113, Transport Airplane Directorate, Aircraft Certification 
Service, 1601 Lind Avenue SW, Renton, Washington 98055-4056; telephone 
(425) 227-2796.

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 arguments 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. 
The proposals described in this notice may be changed in light of the 
comments received. All comments received will be available in the Rules 
Docket for examination by interested persons, both before and after the 
closing date for comments. 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 submitted in response to this notice must include with those 
comments a self-addressed, stamped postcard on which the following 
statement is made: ``Comments to Docket No. NM145.'' The postcard will 
be date stamped and returned to the commenter.

Background

    On August 28, 1992, Lockheed-Martin applied for an amendment to 
Type Certificate No. A1SO to include the new Model 382J. The Model 
382J, which is a derivative of the Model 382G currently approved under 
Type Certificate No. A1S0, is a high wing/low tail configured four-
engine turboprop airplane derived from the Lockheed C-130 Hercules 
military transport. The Model 382J incorporates a new Full Authority 
Digital Engine Controlled (FADEC), Allison engines with six blade 
composite propellers, a modernized cockpit including Electronic Flight 
Instrument Systems (EFIS), Engine Indication and Crew Alerting Systems 
(EICAS), and a Head Up Display (HUD) of primary flight information.
    The increased thrust provided by the new engine/propeller 
installation would result in the Model 382J being limited by ground 
minimum control speed (VMCG) over a large part of the 
proposed takeoff operating envelope, which in turn would result in 
unbalanced takeoff field lengths that Lockheed-Martin finds 
unacceptable. In order to remedy this situation, Lockheed-Martin has 
developed an electronically controlled system that will monitor engine 
and propeller performance, and in the event of a failure of an outboard 
propulsion unit, will reduce the power setting on the functioning 
outboard engine to a level that permits compliance with the 
requirements of Sec. 25.149(e); the operation of this system will thus 
optimize takeoff field lengths for the Model 382J.

Type Certification Basis

    Under the provisions of Sec. 21.101, Lockheed-Martin must show that 
the Model 382J 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 
change to the Model 382J. The regulations incorporated by reference in 
the type certificate are commonly referred to as the ``original type 
certification basis.'' The regulations incorporated by reference in 
Type Certificate No. A1SO are as follows:
    The certification basis for the present Model 382 series airplanes 
is Civil Aviation Regulations (CAR) 9a, which references CAR 4b, 
effective December 31, 1953, including Amendments 4b-1 through 4b-11, 
SR422B, SR450A, and Amendment 4b-12 as related to CAR 4b.307(a).
    The applicable certification basis for the Model 382J is part 25 of 
the Federal Aviation Regulations (FAR) through Amendment 25-80 for all 
new or significantly modified portions of the Model 382J (as compared 
to the present Model 382) and for unmodified portions of the airplane, 
the applicable certification standard will be the rules that were 
effective on February 1, 1965 (part 25, Amendment 25-0). In addition, 
the certification basis includes certain special conditions 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 382J because of a novel or 
unusual design feature, special conditions are prescribed under the 
provisions of Sec. 21.16.
    In addition to the applicable airworthiness regulations and special 
conditions, the Model 382J must comply with the fuel vent and exhaust 
emission requirements of 14 CFR part 34 and the noise certification 
requirements of 14 CFR part 36.
    Special conditions, as appropriate, are issued in accordance with 
Sec. 11.49 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, or should any other model already included on 
the same type certificate be modified to incorporate 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 382J will incorporate the following novel or unusual 
design features:
    The Lockheed Model 382J has an Automatic Control System which will, 
in the event of engine failure on the outboard engine, automatically 
feather the propeller on the engine and will automatically modulate the 
output torque on the opposite engine to reduce asymmetric thrust. This 
system is intended to allow the Model 382J to operate to takeoff 
decision speeds that result in balanced field lengths, when the 
decision speed would otherwise be constrained by ground minimum control 
speed (VMCG).
    The system is resident in each of the two outboard mission 
computers, which will limit the differential torque between the two 
outboard engines by sending torque limit commands to each of the two 
Full Authority Digital Engine Controls on each engine. The differential 
torque limit is a function of ambient condition and airspeed, so that 
in the event of engine failure during takeoff the functional outboard 
engine will have its output torque momentarily reduced, and then 
gradually increased as the airplane continues to accelerate. At a 
certain point in the takeoff, the thrust is restored to its takeoff 
rated value. This torque differential limiting acts in a similar 
fashion if the power is manually reduced by retarding the power lever 
while the airplane is operating in the envelope of atmospheric 
conditions and airspeeds where the ATCS is designed to function.

[[Page 2188]]

Applicability

    As discussed above, these special conditions are applicable to the 
Model 382J. Should Lockheed-Martin 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 provision of Sec. 25.101(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 applicant who applied to the FAA for approval 
of these features on the airplane.

List of Subjects in 14 CFR Part 25

    Air transportation, Aircraft 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 Model 382J airplane.
    1. The ATCS shall be designed so that the combined probability of 
engine failure and ATCS failure is extremely improbable (on the order 
of 1  x  10-9 per flight hour). Inadvertent operation of the ATCS shall 
be improbable (on the order of 1  x  10-5 per flight hour). These 
requirements may drive the necessity for automatic fault detection and 
annunciation and/or periodic functional checks. For the purposes of 
this requirement, the ATCS is intended to include but is not limited 
to, all engine failure detection means, all sensor inputs used to 
compute thrust modulation requirements, all communication provisions 
between system components (Mil-Std-1553 bus, for example), and 
actuation mechanisms for the propeller feathering and outboard engine 
thrust control.
    2. Flight deck annunciation of the armed state of the ATCS shall be 
provided. ATCS failed or not armed must be incorporated into the 
takeoff configuration warning system, or alternatively, a visual 
annunciation can be incorporated if the annunciation lies within the 
primary field of view of both pilots.
    3. Provisions for flightcrew override of the ATCS must be provided. 
The provisions must be through power level actuation, or alternatively, 
through other means provided the means (1) is located on or forward of 
the power levers, (2) is easily identified and operated under all 
operating conditions by either pilot with the hand that is normally 
used to actuate the power levers, and (3) meets the location, sense of 
motion, and accessibility requirements of Sec. 25.777(a), (b), and (c).
    4. The critical engine must be identified for the performance 
requirements of paragraphs 5 and 6 below, i.e., the performance must 
account for failure of a critical outboard engine with the ATCS 
(including autofeather) operating, or failure of the critical inboard 
engine to a feathered propeller condition, whichever is more adverse.
    5. The performance must conservatively account for the failure of 
the critical engine at the critical point in the takeoff path. The 
effect of the ATCS thrust modulation on the gross and net takeoff paths 
must be modeled into the published performance data. The approved 
takeoff distance established in accordance with Sec. 25.113 must 
account for the adverse effect of ATCS on thrust-to-weight ratio.
    6. The one-engine-inoperative climb gradient requirements of 
Sec. 25.121 must be met at the critical power operating condition for 
each climb segment. The most critical adverse effect of the ATCS on the 
thrust-to-weight ratio must be accounted for in establishing the climb 
limited weights for all ambient conditions within the approved 
envelope.
    7. The determination of minimum control speeds must account for the 
critical failure mode (ATCS controlled outboard engine failure versus 
feathered propeller inboard engine failure) for directional 
controllability.
    8. Any reduced takeoff power procedures must be shown compatible 
with operation of the ATCS and must not result in any reduction in the 
level of safety established for operation of the airplane with normal 
takeoff power settings and ATCS operating.
    9. The ATCS must clearly indicate to the crew when it has been 
activated, and indicate that the output torque from the modulated 
engine is being adequately controlled by the ATCS.

    Issued in Renton, Washington, on January 2, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service, ANM-100.
[FR Doc. 98-864 Filed 1-13-98; 8:45 am]
BILLING CODE 4910-13-P