[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
[[Page 2187]]
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
