[Federal Register Volume 59, Number 241 (Friday, December 16, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-30955]
[[Page Unknown]]
[Federal Register: December 16, 1994]
VOL. 59, NO. 241
Friday, December 16, 1994
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM-103; Notice No. SC-94-4-NM]
Special Conditions: Dassault Aviation Model Falcon 2000 Airplane;
Automatic Takeoff Thrust Control System
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed special conditions.
-----------------------------------------------------------------------
SUMMARY: This notice proposes special conditions for the Dassault
Aviation Model Falcon 2000 airplane. This new airplane will have an
unusual design feature associated with an Automatic Takeoff Thrust
Control System (ATTCS), for which the applicable airworthiness
regulations do not contain appropriate safety standards for approach
climb performance using an ATTCS. 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 January 17, 1995.
ADDRESSES: Comments on these proposed special conditions may be mailed
in duplicate to: Federal Aviation Administration, Office of the
Assistant Chief Counsel, Attn.: Rules Docket (ANM-7), Docket No. NM-
103, 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-103.'' Comments may be
inspected in the Rules Docket weekdays, except Federal holidays,
between 7:30 a.m. and 4 p.m.
FOR FURTHER INFORMATION CONTACT:
Stephen Slotte, FAA, Standardization Branch, ANM-113, Transport
Airplane Directorate, Aircraft Certification Service, 1601 Lind Avenue
SW., Renton, Washington, 98055-4056, telephone (206) 227-2797.
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
before further rulemaking action is taken on these proposals. The
proposals contained in this notice may be changed in light of the
comments received. All comments submitted 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
request must submit with those comments a self-addressed, stamped
postcard on which the following statement is made: ``Comments to Docket
No. NM-103.'' The postcard will be date stamped and returned to the
commenter.
Background
On September 13, 1989, Dassault Aviation, B.P. 24, 33701
Merignac, Cedex, France, applied for a new type certificate
in the transport airplane category for the Model Falcon 2000 airplane.
The Dassault Aviation Model Falcon 2000 is a medium-sized
transcontinental business jet powered by two General Electric/Garrett
CFE 738 turbofan engines mounted on pylons extending from the aft
fuselage. Each engine will be capable of delivering 5,600 lbs. thrust.
The airplane will be capable of operation with two flight crewmembers
and eight passengers.
The Model Falcon 2000 will incorporate an unusual design feature,
the Automatic Takeoff Thrust Control System (ATTCS), referred to by
Dassault as Automatic Power Reserve or APR, to show compliance with the
approach climb requirements of Sec. 25.121(d). Appendix I to part 25
limits the application of performance credit for ATTCS to takeoff only.
Since the airworthiness regulations do not contain appropriate safety
standards for approach climb performance using ATTCS, special
conditions are required to ensure a level of safety equivalent to that
established in the regulations.
Type Certification Basis
Under the provisions of Sec. 21.17 of the FAR, Dassault Aviation
must show that the Falcon 2000 meets the applicable provisions of part
25, effective February 1, 1965, as amended by Amendments 25-1 through
25-69. The certification basis may also include later amendments to
part 25 that are not relevant to these special conditions. In addition,
the certification basis for the Falcon 2000 includes part 34, effective
September 10, 1990, plus any amendments in effect at the time of
certification; and part 36, effective December 1, 1969, as amended by
Amendments 36-1 through the amendment in effect at the time of
certification. These special conditions form an additional part of the
type certification basis. In addition, the certification basis may
include other special conditions that are not relevant to these 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 Dassault Aviation Model Falcon
2000 because of a novel or unusual design feature, special conditions
are prescribed under the provisions of Sec. 21.16 to establish a level
of safety equivalent to that established in the regulations.
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, and become part of the type certification basis in
accordance with Sec. 21.17(a)(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 Falcon 2000 will incorporate an unusual design feature,
the ATTCS (referred to by Dassault as the Automatic Power Reserve or
APR), to show compliance with the approach climb requirements of
Sec. 25.121(d). The FALCON 2000 is a twin-turbofan-powered airplane
equipped with Full Authority Digital Engine Controls (FADECs) that, in
part, protect against exceeding engine limits. Further, the FALCON 2000
incorporates a non-moving throttle system that functions by placing the
throttle levers in detents for the takeoff and climb phases of flight,
allowing the FADEC to schedule power setting based on flight phase.
With the throttle levers placed in either of the two forward detents
(takeoff/go-around and climb), if an engine failure (RPM (N1))
difference of greater than 10 percent between engines is sensed, power
is automatically advanced on the remaining engine to the APR power
level associated with the detent. The system is permanently armed and
will function any time the throttle levers are in either of the two
forward detents and an engine failure is sensed. Additionally, as in
the case of an APR failure, or in an all-engines mode, the crew can
select APR by placing the throttle levers in either of the two forward
detents and manually activating the system using an instrument panel-
mounted override switch.
APR power levels manifest themselves as an increase in the engine
flat-rating temperature for the operating altitude, and, in general,
result in higher thrust levels than those associated with the throttle
detents alone. Dassault also makes reference in the APR logic
description to thrust increase being armed for a throttle lever angle
above 27 degrees (max cruise position), but does not make it clear in
the system description if the APR system functions when the throttle is
not in a detent. Further discussions with Dassault make it clear that
when the throttle is between two detents, the FADEC makes a linear
intepolation between the related tables of corrected N1; i.e., an
almost linear thrust change. As function outside of a detent is
possible, then a throttle angle of 28 degrees (arming angle + 1 degree)
would produce almost no additional thrust when APR is activated, while
1 degree before the next detent (max cruise/max continuous) would
produce almost the same thrust increase as when the throttle is in that
detent. Logic for the max climb/max continuous detents is the same.
From a practical point of view, throttle positions between the detents
are not used.
The part 25 standards for ATTCS, contained in Sec. 25.904 and
Appendix I, specifically restrict performance credit for ATTCS to
takeoff. Expanding the scope of the standards to include other phases
of flight, including go-around, was considered at the time the
standards were issued, but flightcrew workload issues precluded further
consideration. As stated in the preamble to Amendment 25-62:
In regard to ATTCS credit for approach climb and go-around
maneuvers, current regulations preclude a higher thrust for the
approach climb (Sec. 25.121(d)) than for the landing climb
(Sec. 25.119). The workload required for the flightcrew to monitor
and select from multiple in-flight thrust settings in the event of
an engine failure during a critical point in the approach, landing,
or go-around operations is excessive. Therefore, the FAA does not
agree that the scope of the amendment should be changed to include
the use of ATTCS for anything except the takeoff phase. (52 FR
43153, November 9, 1987)
The ATTCS incorporated on the FALCON 2000 allows the pilot to use
the same power setting procedure during a go-around, regardless of
whether or not an engine fails. In either case, the pilot obtains go-
around power by moving the throttles into the forward (takeoff/go-
around) throttle detent. Since the ATTCS is permanently armed, it will
function automatically following an engine failure, and advance the
remaining engine to the ATTCS thrust level. Therefore, this design
adequately addresses the pilot workload concerns identified in the
preamble to Amendment 25-62. Accordingly, these proposed special
conditions would require a showing of compliance with those provisions
of Sec. 25.904 and Appendix I that are applicable to the approach climb
and go-around maneuvers.
The definition of a critical time interval for the approach climb
case, during which time it must be extremely improbable to violate a
flight path based on the Sec. 25.121(d) gradient requirement, is of
primary importance. The Sec. 25.121(d) gradient requirement implies a
minimum one-engine-inoperative flight path capability with the airplane
in the approach configuration. The engine may have been inoperative
before initiating the go-around, or it may become inoperative during
the go-around. The definition of the critical time interval must
consider both possibilities.
As discussed above, these proposed special conditions would be
applicable to the Dassault Aviation Model Falcon 2000. Should Dassault
Aviation apply at a later date for a change to the type certificate to
include another model incorporating the same novel or unusual design
feature, these special conditions would apply to that model as well
under the provisions of Sec. 21.101(a)(1).
Conclusion
This action affects only certain design features on the Dassault
Aviation Model Falcon 2000 airplane. It is not a rule of general
applicability and 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
Aircraft, Aviation safety, Reporting and recordkeeping
requirements.
The authority citation for these proposed special conditions is as
follows:
Authority: 49 U.S.C. app. 1344, 1348(c), 1352, 1354(a), 1355,
1421 through 1431, 1502, 1651(b)(2), 42 U.S.C. 1857f-10, 4321 et
seq.; E.O. 11514; and 49 U.S.C. 106(g).
The Proposed Special Conditions
Accordingly, the Federal Aviation Administration (FAA) proposes the
following special conditions as part of the type certification basis
for the Dassault Aviation Model Falcon 2000 airplane.
(a) General: An ATTCS is defined as the entire automatic system,
including all devices, both mechanical and electrical, that sense
engine failure, transmit signals, actuate fuel controls or power
levers, or increase engine power by other means on operating engines to
achieve scheduled thrust or power increases and furnish cockpit
information on system operation.
(b) Automatic takeoff thrust control system (ATTCS). The engine
power control system that automatically resets the power or thrust on
the operating engine (following engine failure during the approach for
landing) must comply with the following requirements:
(1) Performance and System Reliability Requirements. The
probability analysis must include consideration of ATTCS failure
occurring after the time at which the fightcrew last verifies that the
ATTCS is in a condition to operate until the beginning of the critical
time interval.
(2) Thrust Setting. The initial takeoff thrust set on each engine
at the beginning of the takeoff roll or go-around may not be less than:
(i) Ninety (90) percent of the thrust level set by the ATTCS (the
maximum takeoff thrust or power approved for the airplane under
existing ambient conditions);
(ii) That required to permit normal operating of all safety-related
systems and equipment dependent upon engine thrust or power lever
position; or
(iii) That shown to be free of hazardous engine response
characteristics when thrust is advanced from the initial takeoff thrust
or power to the maximum approved takeoff thrust or power.
(3) Powerplant Controls. In addition to the requirements of
Sec. 25.1141, no single failure or malfunction, or probable combination
thereof, of the ATTCS, including associated systems, may cause the
failure of any powerplant function necessary for safety. The ATTCS must
be designed to:
(i) Apply thrust or power on the operating engine(s), following any
one engine failure during takeoff or go-around, to achieve the maximum
approved takeoff thrust or power without exceeding engine operating
limits; and
(ii) Provide a means to verify to the flightcrew before takeoff and
before beginning an approach for landing that the ATTCS is in a
condition to operate.
(c) Critical Time Interval. The definition of the Critical Time
Interval in Appendix I, Section 125.2(b) shall be expanded to include
the following:
(1) When conducting an approach for landing using ATTCS, the
critical time interval is defined as follows:
(i) The critical time interval begins at a point on a 2.5 degree
approach glide path from which, assuming a simultaneous engine and
ATTCS failure, the resulting approach climb flight path intersects a
flight path originating at a later point on the same approach path
corresponding to the Part 25 one-engine-inoperative approach climb
gradient. The period of time from the point of simultaneous engine and
ATTCS failure to the intersection of these flight paths must be no
shorter than the time interval used in evaluating the critical time
interval for takeoff beginning from the point of simultaneous engine
and ATTCS failure and ending upon reaching a height of 400 feet.
(ii) The critical time interval ends at the point on a minimum
performance, all-engines-operating go-around flight path from which,
assuming a simultaneous engine and ATTCS failure, the resulting minimum
approach climb flight path intersects a flight path corresponding to
the Part 25 minimum one-engine-inoperative approach climb gradient. The
all-engines-operating go-around flight path and the Part 25 one-engine-
inoperative approach climb gradient flight path originate from a common
point on a 2.5 degree approach path. The period of time from the point
of simultaneous engine and ATTCS failure to the intersection of these
flight paths must be no shorter than the time interval used in
evaluating the critical time interval for the takeoff beginning from
the point of simultaneous engine and ATTCS failure and ending upon
reaching a height of 400 feet.
(2) The critical time interval must be determined at the altitude
resulting in the longest critical time interval for which one-engine-
inoperative approach climb performance data are presented in the
Airplane Flight Manual.
(3) The critical time interval is illustrated in the following
figure:
BILLING CODE 4910-13-M
TP16DE94.070
BILLING CODE 4910-13-C
*The engine and ATTCS failed time interval must be no shorter
than the time interval from the point of simultaneous engine and
ATTCS failure to a height of 400 feet used to comply with I25.2(b)
for ATTCS use during takeoff.
Issued in Renton, Washington, on December 2, 1994.
Darrell M. Pederson,
Acting Manager Transport Airplane Directorate Aircraft Certification
Service, ANM-100.
[FR Doc. 94-30955 Filed 12-15-94; 8:45 am]
BILLING CODE 4910-13-M
