[Federal Register Volume 63, Number 211 (Monday, November 2, 1998)]
[Proposed Rules]
[Pages 58660-58671]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-29301]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 23
[Docket No. CE145, Notice No. 23-98-01-SC]
Special Conditions; Raytheon Model 390 Airplane
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed special conditions.
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SUMMARY: This notice proposes special conditions for the Raytheon
Aircraft Company Model 390 airplane. This new airplane will have novel
and unusual design features not typically associated with normal,
utility, acrobatic, and commuter category airplanes. These design
features include turbofan engines, engine location, swept wings and
stabilizer, and certain performance characteristics necessary for this
type of airplane, for which the applicable regulations do not contain
adequate or appropriate airworthiness standards. This notice contains
the additional airworthiness standards that the Administrator considers
necessary to establish a level of safety equivalent to that existing in
the current business jet fleet and expected by the user of this class
of aircraft.
DATES: Comments must be received on or before December 2, 1998.
ADDRESSES: Comments on this proposal may be mailed in duplicate to:
Federal Aviation Administration, Regional Counsel, ACE-7, Attention:
Rules Docket Clerk, Docket No. CE145, Room No. 1558, 601 East 12th
Street, Kansas City, Missouri 64106. All comments must be marked:
Docket No. CE145. 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: Lowell Foster, Aerospace Engineer,
Standards Office (ACE-110), Small Airplane Directorate, Aircraft
Certification Service, Federal Aviation Administration, Room 1544, 601
East 12th Street, Kansas City, Missouri 64106; telephone (816) 426-
5688.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of
these 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 specified above will be considered by the
Administrator before taking further rulemaking action on this proposal.
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. CE145.'' The postcard will be date stamped and returned
to the commenter. 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
concerned with this rulemaking will be filed in the docket.
Background
On August 1, 1995, Raytheon Aircraft Company (then Beech Aircraft
Corporation), 9707 East Central, Wichita, Kansas 67201, made
application for 14 CFR part 23 normal category type certification of
its Model 390 airplane. The Model 390 has a composite fuselage, a metal
wing with 22.8 degrees of leading-edge sweepback, and a combination
composite/metal empennage in a T-tail configuration with trimmable
horizontal tail with 27.3 degrees of leading-edge sweepback. The
airplane will accommodate six passengers and a crew of two. The Model
390 will have a VMO/MMO of 320 knots/M.83, and
has two turbofan engines mounted on the aft fuselage above and behind
the wing.
Type Certification Basis
Type certification basis of the Model 390 airplane is as follows:
14 CFR part 23, effective February 1, 1965, through Amendment 23-52,
effective July 25, 1996; 14 CFR part 36, effective December 1, 1969,
through the amendment effective on the date of type certification; 14
CFR part 34; exemptions, if any; and the special conditions adopted by
this rulemaking action.
Discussion
Special conditions may be issued and amended, as necessary, as part
of the type certification basis if the Administrator finds that the
airworthiness standards designated in accordance with 14 CFR part 21,
Sec. 21.17(a)(1), do not contain adequate or appropriate safety
standards because of novel or unusual design features of an airplane.
Special conditions, as appropriate, are issued in accordance with 14
CFR part 11, Sec. 11.49, after public notice, as required by
Secs. 11.28 and 11.29(b), effective October 14, 1980, and become part
of the type certification basis as provided by part 21,
Sec. 21.17(a)(2).
Raytheon plans to incorporate certain novel and unusual design
features into the Model 390 airplane for which the airworthiness
regulations do not contain adequate or appropriate safety standards.
These features include turbofan engines, engine location, swept wings
and stabilizer, and certain performance characteristics necessary for
this type of airplane.
Performance
The Raytheon Model 390 has a wing with 22.8 degrees of leading-edge
sweepback and a T-tail configuration with trimmable horizontal
stabilizer with 27.3 degrees of leading-edge sweepback. The Model 390
will have a VMO/MMO of 320 knots/M.83, and it
will have two turbofan engines mounted on the aft fuselage.
Previous certification and operational experience with airplanes of
like design in the transport category reveal certain unique
characteristics compared to conventional aircraft certificated under
part 23. These characteristics have caused safety problems in the past
when pilots attempted takeoffs and landings, particularly with a large
variation in temperature and altitude, using procedures and instincts
developed with conventional airplanes.
One of the major distinguishing features of a swept-wing design not
considered in current part 23 is a characteristically flatter lift
curve without a ``stall'' break near the maximum coefficient of lift,
as in a conventional wing. The ``stall'' separation point may occur at
a much higher angle of attack than the point of maximum lift, and the
angle of attack for maximum lift can be only recognized by precise test
measurements or specific detection systems. This phenomenon is not
apparent to a pilot accustomed to operating a conventional airplane
where
[[Page 58661]]
increasing angle of attack produces increased lift to the point where
the wing stalls. In a swept-wing design, if the pilot does not operate
in accordance with established standards developed through a dedicated
test program, increasing angle of attack may produce very little lift
yet increase drag markedly to the point where flight is impossible.
These adverse conditions may be further compounded by the
characteristics of turbofan engines, including specified N1/
N2 rotational speeds, temperature, and pressure limits that
make its variation in thrust output with changes in temperature and
altitude more complex and difficult to predict. In recognition of these
characteristics, Special Civil Air Regulations No. SR-422 and follow-on
regulations established weight-altitude-temperature (WAT) limitations
and procedures for scheduling takeoff and landing for turbine powered
transport category airplanes, so the pilot could achieve reliable and
repeatable results under all expected conditions of operation. This
entails specific tests such as minimum unstick speed, VMU,
to ensure that rotation and fly-out speeds are correct and that the
airplane speed schedule will not allow the airplane to lift off in
ground effect and then be unable to accelerate and continue to climb
out. In conjunction with the development of takeoff and landing
procedures, it was also necessary to establish required climb gradients
and data for flight path determination under all approved weights,
altitudes, and temperatures. This enables the pilot to determine,
before takeoff, that a safe takeoff, departure, and landing at
destination can be achieved.
Takeoff
Based upon the knowledge and experience gained with similar high
speed, high efficiency turbojet airplanes, special conditions require
performance standards for takeoff, takeoff speeds, accelerate-stop
distance, takeoff path, takeoff distance, takeoff run, and takeoff
flight path.
Additionally, procedures for takeoff, accelerate-stop distance, and
landing are proposed as those established for operation in service and
must be executable by pilots of average skill and include reasonably
expected time delays.
Climb
To maintain a level of safety that is equivalent to the current
business jet fleet for takeoff, takeoff speeds, takeoff path, takeoff
distance, and takeoff run, it is appropriate to require specific climb
gradients, airplane configurations, and consideration of atmospheric
conditions that will be encountered. These special conditions include
climb with one engine inoperative, balked landing climb, and general
climb conditions.
Landing
Landing distance determined for the same parameters is consistent
with takeoff information for the range of weights, altitudes, and
temperatures approved for operation. Further, it is necessary to
consider time delays to provide for in-service variation in the
activation of deceleration devices such as spoilers and brakes.
Trim
Special conditions are issued to maintain a level of safety that is
consistent with the use of VMO/MMO and the
requirements established for previous part 23 jet airplanes. Current
standards in part 23 did not envision this type of airplane and the
associated trim considerations.
Demonstration of Static Longitudinal Stability
To maintain a level of safety consistent with existing business jet
airplanes, it is appropriate to define applicable requirements for
static longitudinal stability. Current standards in part 23 did not
envision this type of airplane and the associated stability
considerations. Special conditions will establish static longitudinal
stability requirements that include a stick force versus speed
specification and stability requirements applicable to high speed jet
airplanes.
Consistent with the concept of VMO/MMO being
a maximum operational speed limit, rather than a limiting speed for the
demonstration of satisfactory flight characteristics, it is appropriate
to extend the speed for demonstration of longitudinal stability
characteristics from the VMO/MMO of 14 CFR part
23 to the maximum speed for stability characteristics, VFC/
MFC, for this airplane.
Static Directional and Lateral Stability
Consistent with the concept of VMO/MMO being
a maximum operational speed limit, rather than a limiting speed for the
demonstration of satisfactory flight characteristics, it is appropriate
to extend the speed for demonstration of lateral/directional stability
characteristics from the VMO/MMO of part 23 to
the maximum speed for stability characteristics, VFC/
MFC for this airplane.
Stall Characteristics
The stall characteristics requirements are relaxed from part 23 to
be equivalent to that acceptable in current business jets. These
special conditions reflect a higher expected pilot proficiency level,
the remote chance that a stall will be encountered in normal operation,
and the requirements are relaxed as compensation for meeting the higher
performance requirements in these special conditions.
Vibration and Buffeting
The Raytheon Model 390 will be operated at high altitudes where
stall-Mach buffet encounters (small speed margin between stall and
transonic flow buffet) are likely to occur, which is not presently
addressed in part 23. The special condition will require buffet onset
tests and the inclusion of information in the Airplane Flight Manual
(AFM) to provide guidance to the flightcrew. This information will
enable the flightcrew to plan flight operations that will maximize the
maneuvering capability during high altitude cruise flight and preclude
intentional operations exceeding the boundary of perceptible buffet.
Buffeting is considered to be a warning to the pilot that the airplane
is approaching an undesirable and eventually dangerous flight regime,
that is, stall buffeting, high speed buffeting or maneuvering (load
factor) buffeting. In straight flight, therefore, such buffet warning
should not occur at any normal operating speed up to the maximum
operating limit speed, VMO/MMO.
High Speed Characteristics and Maximum Operating Limit Speed
The Raytheon Model 390 will be operated at high altitude and high
speeds. The proposed operating envelope includes areas in which Mach
effects, which have not been considered in part 23, may be significant.
The anticipated low drag of the airplane and the proposed operating
envelope are representative of the conditions not envisioned by the
existing part 23 regulations. These conditions may degrade the ability
of the flightcrew to promptly recover from inadvertent excursions
beyond maximum operating speeds. The ability to pull a positive load
factor is needed to ensure, during recovery from upset, that the
airplane speed does not continue to increase to a value where recovery
may not be achievable by the average pilot or flightcrew.
Additionally, to allow the aircraft designer to conservatively
design to higher speeds than may be operationally
[[Page 58662]]
required for the airplane, the concept of VDF/
MDF, the highest demonstrated flight speed for the type
design, is appropriate for this airplane. This permits VD/
MD, the design dive speed, to be higher than the speed
actually required to be demonstrated in flight. Accordingly, the
special conditions allow one to determine a maximum demonstrated flight
speed and to relate the speeds VMO/MMO and
VDF/MDF.
Flight Flutter Tests
Flight flutter test special conditions are proposed to
VDF/MDF rather than to VD, in keeping
with the VDF/MDF concept.
Out-of-Trim Characteristics
High speed airplanes have experienced a number of upset incidents
involving out-of-trim conditions. This is particularly true for swept-
wing airplanes and airplanes with a trimmable stabilizer. Service
experience has shown that out-of-trim conditions can occur in flight
for various reasons and that the control and maneuvering
characteristics of the airplane may be critical in recovering from
upsets. The existing part 23 regulations do not address high speed out-
of-trim conditions. These special conditions test the out-of-trim
flight characteristics by requiring the longitudinal trim control be
displaced from the trimmed position by the amount resulting from the
three-second movement of the trim system at this normal rate with no
aerodynamic load, or the maximum mis-trim that the autopilot can
sustain in level flight in the high speed cruise condition, whichever
is greater. Special conditions require the maneuvering characteristics,
including stick force per g, be explored throughout a specified
maneuver load factor speed envelope. The dive recovery characteristics
of the aircraft in the out-of-trim condition specified would be
investigated to determine that safe recovery can be made from the
demonstrated flight dive speed VDF/MDF.
Takeoff Warning System
Jet airplanes incorporating leading-edge sweep in the wing and
horizontal tail and incorporating a trimmable horizontal tail have had
accidents because of the criticality of the airplane's configuration at
takeoff. Unlike simple, straight wing airplanes, an incorrect flap or
horizontal tail trim setting can significantly alter the takeoff
distance. Special conditions to require a takeoff warning system are
proposed to maintain a level of safety appropriate for this class of
aircraft.
Engine Fire Extinguishing System
The Model 390 design includes engines mounted aft on the fuselage;
therefore, early visual detection of engine fires is precluded. The
applicable existing regulations do not require fire extinguishing
systems for engines. Aft mounted engine installations were not
envisaged in the development of part 23; therefore, special conditions
for a fire extinguishing system with the applicable agents, containers,
and materials for the engines of the Model 390 are appropriate.
Airspeed Indicating System
To maintain a level of safety consistent with that existing in the
current business jet fleet, and to be consistent with the establishment
of speed schedule performance requirements, it is appropriate to
establish applicable requirements for determining and providing
airspeed indicating system calibration information. Additionally, it is
appropriate to establish special conditions requiring protection of the
pilot tube from malfunctions associated with icing conditions. Special
conditions will establish airspeed indicating system calibration and
pilot tube ice protection requirements applicable to transport category
jet airplanes.
Static Pressure System
Special conditions are appropriate to establish applicable
requirements for providing static pressure system calibration
information in the AFM. Since aircraft of this type are frequently
equipped with devices to correct the altimeter indication, it is also
appropriate to establish requirements to ensure the continued
availability of altitude information where such a device malfunctions.
Current standards in part 23 did not envision this type of airplane and
the associated static pressure requirements.
Minimum Flightcrew
The Raytheon Model 390 operates at high altitudes and speeds not
envisioned in part 23 and must be flown in a precise speed schedule to
achieve flight manual takeoff and landing distances. Therefore, it is
appropriate to specify workload considerations. Special conditions will
specify the items to be considered in workload determination.
Airplane Flight Manual (AFM) Information
To be consistent with the performance special conditions, it is
also necessary to require that the maximum takeoff and landing weights,
takeoff distances, and associated atmospheric conditions be made
available to the pilot in the AFM and that the airplane be operated
within its performance capabilities. Special conditions will add
maximum takeoff weights, maximum landing weights, and minimum takeoff
distances as limitations in the AFM. Additionally, special conditions
are included to add takeoff flight path and procedures necessary to
achieve the performance in the limitations section as information in
the AFM.
Effects of Contamination on Natural Laminar Flow Airfoils
Airfoil configurations similar to the Raytheon Model 390 had
measurable degradations of handling qualities and performance when
laminar flow was lost due to airfoil contamination. Tripping of the
boundary layer could be caused from flight in precipitation conditions
or by the presence of contamination such as insects. If measurable
effects are detected, it should be determined that the minimum flight
characteristics standards continue to be met and that any degradations
to performance information are identified. This may be accomplished by
a combination of analysis and testing. Current standards in part 23 did
not envision this type of airplane and the associated airfoil
contamination considerations. Special considerations are issued since
existing regulations do not require these adverse effects to be
evaluated.
Conclusion
In view of the design features discussed for the Raytheon Model 390
airplane, the following special conditions are proposed. This action is
not a rule of general applicability and affects only the model/series
of airplane identified.
List of Subjects in 14 CFR Part 23
Aircraft, Aviation Safety, Signs and Symbols.
Citation
The authority citation for these Special Conditions is as follows:
Authority: 49 U.S.C. 106(g); 40113, 44701, 44702, and 44704; 14
CFR 21.16 and 21.17; and 14 CFR 11.28 and 11.29(b).
The Proposed Special Conditions
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes the
following special conditions as part of the type
[[Page 58663]]
certification basis for the Raytheon Model 390 airplane:
SC23.45 Performance: General.
Instead of the requirements of Sec. 23.45(g) and (h), the following
apply:
(g) The following, as applicable, must be determined on a smooth,
dry, hard-surfaced runway--
(1) Takeoff distance of special condition SC23.53;
(2) Accelerate-stop distance of special condition SC23.55;
(3) Takeoff distance and takeoff run of special condition SC23.59;
and
(4) Landing distance of special condition SC23.75.
Note: The effect on these distances of operation on other types
of surfaces (for example, grass, gravel), when dry, may be
determined or derived and these surfaces listed in the Airplane
Flight Manual.
(h) Unless otherwise prescribed, the applicant must select the
takeoff, enroute, approach, and landing configurations for the
airplane.
In addition to the requirements of Sec. 23.45 and the paragraphs
above, the following apply:
(i) The airplane configurations may vary with weight, altitude, and
temperature to the extent that they are compatible with the operating
procedures required by paragraph (d) of this special condition.
(j) Unless otherwise prescribed, in determining the accelerate-stop
distances, takeoff flight paths, takeoff distances, and landing
distances, changes in the airplane's configuration, speed, power, and
thrust, must be made in accordance with procedures established by the
applicant for operation in service.
(k) Procedures for the execution of balked landings and
discontinued approaches associated with the conditions prescribed in
special conditions SC23.77 and SC23.67(d) must be established.
(l) The procedures established under paragraphs (d) and (e) of this
special condition must:
(1) Be able to be consistently executed in service by crews of
average skill;
(2) Use methods or devices that are safe and reliable; and
(3) Include allowance for any time delays in the execution of the
procedures that may reasonably be expected in service.
SC23.49 Stalling speed.
In Sec. 23.49(b), change the reference from ``Sec. 23.201'' to
``Sec. 23.201 and special condition SC23.201.''
SC23.51 Takeoff speeds.
Instead of compliance with Sec. 23.51, the following apply:
(a) V1 must be established in relation to
VEF, as follows:
(1) VEF is the calibrated airspeed at which the critical
engine is assumed to fail. VEF must be selected by the
applicant, but may not be less than VMCG determined under
Sec. 23.149(f) and special condition SC23.149(f).
(2) V1, in terms of calibrated airspeed, is the takeoff
decision speed selected by the applicant; however, V1 may
not be less than VEF plus the speed gained with the critical
engine inoperative during the time interval between the instant at
which the critical engine failed and the instant at which the pilot
recognizes and reacts to the engine failure, as indicated by the
pilot's application of the first retarding means during the accelerate-
stop test.
(b) V2 min, in terms of calibrated airspeed, may not be
less than the following:
(1) 1.2 VS1, or
(2) 1.10 times VMC established under Sec. 23.149.
(c) V2, in terms of calibrated airspeed, must be
selected by the applicant to provide at least the gradient of climb
required by special condition SC23.67(b), but may not be less than the
following:
(1) V2 min, and
(2) VR plus the speed increment attained (in accordance
with special condition SC23.57(c)(2)) before reaching a height of 35
feet above the takeoff surface.
(d) VMU is the calibrated airspeed at and above which
the airplane can safely lift off the ground and continue the takeoff.
VMU speeds must be selected by the applicant throughout the
range of thrust-to-weight ratios to be certified. These speeds may be
established from free-air data if these data are verified by ground
takeoff tests.
(e) VR, in terms of calibrated airspeed, must be
selected in accordance with the following conditions of paragraphs
(e)(1) through (e)(4) of this special condition:
(1) VR may not be less than the following:
(i) V1;
(ii) 105 percent of VMC;
(iii) The speed (determined in accordance with special condition
SC23.57(c)(2)) that allows reaching V2 before reaching a
height of 35 feet above the takeoff surface; or
(iv) A speed that, if the airplane is rotated at its maximum
practicable rate, will result in a VLOF of not less than 110
percent of VMU in the all-engines-operating condition and
not less than 105 percent of VMU determined at the thrust-
to-weight ratio corresponding to the one-engine-inoperative condition.
(2) For any given set of conditions (such as weight, configuration,
and temperature), a single value of VR, obtained in
accordance with this special condition, must be used to show compliance
with both the one-engine-inoperative and the all-engines-operating
takeoff provisions.
(3) It must be shown that the one-engine-inoperative takeoff
distance, using a rotation speed of 5 knots less than VR,
established in accordance with paragraphs (e)(1) and (e)(2) of this
special condition, does not exceed the corresponding one-engine-
inoperative takeoff distance using the established VR. The
takeoff distances must be determined in accordance with special
condition SC23.59(a)(1).
(4) Reasonably expecting variations in service from the established
takeoff procedures for the operation of the airplane (such as over-
rotation of the airplane and out-of-trim conditions) may not result in
unsafe flight characteristics or in marked increases in the scheduled
takeoff distances established in accordance with special condition
SC23.59.
(f) VLOF is the calibrated airspeed at which the
airplane first becomes airborne.
SC23.53 Takeoff performance.
Instead of complying with Sec. 23.53, the following apply:
(a) In special conditions SC23.51, SC23.55, SC23.57 and SC23.59,
the takeoff speeds, the accelerate-stop distance, the takeoff path, the
takeoff distance, and takeoff run described must be determined:
(1) At each weight, altitude, and ambient temperature within the
operation limits selected by the applicant; and
(2) In the selected configuration for takeoff.
(b) No takeoff made to determine the data required by this section
may require exceptional piloting skill or alertness.
(c) The takeoff data must be based on a smooth, dry, hard-surfaced
runway.
(d) The takeoff data must include, within the established
operational limits of the airplane, the following operational
correction factors:
(1) Not more than 50 percent of nominal wind components along the
takeoff path opposite to the direction of takeoff, and not less than
150 percent of nominal wind components along the takeoff path in the
direction of takeoff; and
(2) Effective runway gradients.
[[Page 58664]]
SC23.55 Accelerate-stop distance.
In the absence of specific accelerate-stop distance requirements,
the following apply:
(a) The accelerate-stop distance is the sum of the distances
necessary to--
(1) Accelerate the airplane from a standing start to VEF
with all engines operating;
(2) Accelerate the airplane from VEF to V1,
assuming that the critical engine fails at VEF; and
(3) Come to a full stop from the point at which V1 is
reached assuming that, in the case of engine failure, the pilot has
decided to stop as indicated by application of the first retarding
means at the speed V1.
(b) Means other than wheel brakes may be used to determine the
accelerate-stop distance if that means--
(1) Is safe and reliable;
(2) Is used so that consistent results can be expected under normal
operating conditions; and
(3) Is such that exceptional skill is not required to control the
airplane.
(c) The landing gear must remain extended throughout the
accelerate-stop distance.
SC23.57 Takeoff path.
In the absence of specific takeoff path requirements, the following
apply:
(a) The takeoff path extends from a standing start to a point in
the takeoff at which the airplane is 1,500 feet above the takeoff
surface or at which the transition from the takeoff to the enroute
configuration is completed and a speed is reached at which compliance
with special condition SC23.67(c) is shown, whichever point is higher.
In addition, the following apply:
(1) The takeoff path must be based on procedures prescribed in
special condition SC23.45;
(2) The airplane must be accelerated on the ground to
VEF, at which point the critical engine must be made
inoperative and remain inoperative for the rest of the takeoff; and
(3) After reaching VEF, the airplane must be accelerated
to V2.
(b) During the acceleration to speed V2, the nose gear
may be raised off the ground at a speed not less than VR.
However, landing gear retraction may not begin until the airplane is
airborne.
(c) During the takeoff path determination, in accordance with
paragraphs (a) and (b) of this special condition, the following apply:
(1) The slope of the airborne part of the takeoff path must be
positive at each point;
(2) The airplane must reach V2 before it is 35 feet
above the takeoff surface and must continue at a speed as close as
practical to, but not less than, V2 until it is 400 feet
above the takeoff surface;
(3) At each point along the takeoff path, starting at the point at
which the airplane reaches 400 feet above the takeoff surface, the
available gradient of climb may not be less than 1.2 percent; and
(4) Except for gear retraction, the airplane configuration may not
be changed, and no change in power or thrust that requires action by
the pilot may be made, until the airplane is 400 feet above the takeoff
surface.
(d) The takeoff path must be determined by a continuous
demonstrated takeoff or by synthesis from segments. If the takeoff path
is determined by the segmental method, the following apply:
(1) The segments must be clearly defined and must be related to the
distinct changes in the configuration, speed, and power or thrust;
(2) The weight of the airplane, the configuration, and the power or
thrust must be constant throughout each segment and must correspond to
the most critical condition prevailing in the segment;
(3) The flight path must be based on the airplane's performance
without ground effect; and
(4) The takeoff path data must be checked by continuous
demonstrated takeoffs, up to the point at which the airplane is out of
ground effect and its speed is stabilized, to ensure that the path is
conservative relative to the continuous path.
Note: The airplane is considered to be out of the ground effect
when it reaches a height equal to its wing span.
SC23.59 Takeoff distance and takeoff run.
In the absence of specific takeoff distance and takeoff run
requirements, the following apply:
(a) Takeoff distance is the greater of the following:
(1) The horizontal distance along the takeoff path from the start
of the takeoff to the point at which the airplane is 35 feet above the
takeoff surface, determined under special condition SC23.57; or
(2) 115 percent of the horizontal distance along the takeoff path,
with all engines operating, from the start of the takeoff to the point
at which the airplane is 35 feet above the takeoff surface, as
determined by a procedure consistent with special condition SC23.57.
(b) If the takeoff distance includes a clear way, the takeoff run
is the greater of the following:
(1) The horizontal distance along the takeoff path from the start
of the takeoff to a point equidistant between the point at which
VLOF is reached and the point at which the airplane is 35
feet above the takeoff surface, as determined under special condition
SC23.57; or
(2) 115 percent of the horizontal distance along the takeoff path,
with all engines operating, from the start of the takeoff to a point
equidistant between the point at which VLOF is reached and
the point at which the airplane is 35 feet above the takeoff surface,
determined by a procedure consistent with special condition SC23.57.
SC23.61 Takeoff flight path.
In the absence of specific takeoff flight path requirements, the
following apply:
(a) The takeoff flight path begins 35 feet above the takeoff
surface at the end of the takeoff distance determined in accordance
with special condition SC23.59.
(b) The net takeoff flight path data must be determined so that
they represent the actual takeoff flight paths (determined in
accordance with special condition SC23.57 and with paragraph (a) of
this special condition) reduced at each point by a gradient of climb
equal to 0.8 percent.
(c) The prescribed reduction in climb gradient may be applied as an
equivalent reduction in acceleration along that part of the takeoff
flight path at which the airplane is accelerated in level flight.
SC23.63 Climb: general.
Instead of compliance with Sec. 23.63, the following applies:
Compliance with the requirements of special conditions SC23.67 and
SC23.77 must be shown at each weight, altitude, and ambient temperature
within the operational limits established for the airplane and with the
most unfavorable center of gravity for each configuration.
SC23.65 Climb: all engines operating.
Delete requirement of Sec. 23.65.
SC23.66 Takeoff climb: One engine inoperative.
Delete requirement of Sec. 23.66.
SC23.67 Climb: One engine inoperative.
Instead of compliance with Sec. 23.67, the following apply:
(a) Takeoff; landing gear extended. In the critical takeoff
configuration existing along the flight path (between the points at
which the airplane reaches VLOF and at which the landing
gear is fully retracted) and in the configuration used in special
condition SC23.57 without
[[Page 58665]]
ground effect, unless there is a more critical power operating
condition existing later along the flight path before the point at
which the landing gear is fully retracted, the steady gradient of climb
must be positive at VLOF and with the following:
(1) The critical engine inoperative and the remaining engines at
the power or thrust available when retraction of the landing gear
begins in accordance with special condition SC23.57, and
(2) The weight equal to the weight existing when retraction of the
landing gear begins, determined under special condition SC23.57.
(b) Takeoff; landing gear retracted. In the takeoff configuration
existing at the point of the flight path at which the landing gear is
fully retracted and in the configuration used in special condition
SC23.57, without ground effect, the steady gradient of climb may not be
less than 2.4 percent at V2 and with the following:
(1) The critical engine inoperative, the remaining engines at the
takeoff power or thrust available at the time the landing gear is fully
retracted, determined under special condition SC23.57 unless there is a
more critical power operating condition existing later along the flight
path but before the point where the airplane reaches a height of 400
feet above the takeoff surface; and
(2) The weight equal to the weight existing when the airplane's
landing gear is fully retracted, determined under special condition
SC23.57.
(c) Final takeoff. In the enroute configuration at the end of the
takeoff path, determined in accordance with special condition SC23.57,
the steady gradient of climb may not be less than 1.2 percent at not
less than 1.25 VS and with the following:
(1) The critical engine inoperative and the remaining engines at
the available maximum continuous power or thrust; and
(2) The weight equal to the weight existing at the end of the
takeoff path, determined under special condition SC23.57.
(d) Approach. In the approach configuration corresponding to the
normal all-engines-operating procedure in which VS for this
configuration does not exceed 110 percent of the VS for the
related landing configuration, the steady gradient of climb may not be
less than 2.1 percent with the following:
(1) The critical engine inoperative, the remaining engine at the
available in-flight takeoff power or thrust;
(2) The maximum landing weight; and
(3) A climb speed established in connection with normal landing
procedures, but not exceeding 1.5 VS.
SC23.73 Reference landing approach speed.
In Sec. 23.73(b), change the reference from ``Sec. 23.149(c)'' to
``special condition SC23.149.''
SC23.75 Landing distance.
Instead of compliance with Sec. 23.75, the following apply:
(a) The horizontal distance necessary to land and to come to a
complete stop from a point 50 feet above the landing surface must be
determined (for each weight, altitude, temperature, and wind within the
operational limits established by the applicant for the airplane), as
follows:
(1) The airplane must be in the landing configuration;
(2) A steady approach at a gradient of descent not greater than 5.2
percent (3 degrees), with an airspeed of not less than VREF,
determined in accordance with special condition SC23.73, must be
maintained down to the 50-foot height;
(3) Changes in configuration, power or thrust, and speed must be
made in accordance with the established procedures for service
operation;
(4) The landing must be made without excessive vertical
acceleration, tendency to bounce, nose over, ground loop, or porpoise;
(5) The landings may not require exceptional piloting skill or
alertness; and
(6) It must be shown that a safe transition to the balked landing
conditions of special condition SC23.77 can be made from the conditions
that exist at the 50-foot height.
(b) The landing distance must be determined on a level, smooth,
dry, hard-surfaced runway. In addition, the following apply:
(1) The brakes may not be used so as to cause excessive wear of
brakes or tires; and
(2) Means other than wheel brakes may be used if that means is as
follows:
(i) Is safe and reliable;
(ii) Is used so that consistent results can be expected in service;
and
(iii) Is such that exceptional skill is not required to control the
airplane.
(c) The landing distance data must include correction factors for
not more than 50 percent of the nominal wind components along the
landing path opposite to the direction of landing and not less than 150
percent of the nominal wind components along the landing path in the
direction of landing.
(d) If any device is used that depends on the operation of any
engine, and if the landing distance would be noticeably increased when
a landing is made with that engine inoperative, the landing distance
must be determined with that engine inoperative unless the use of
compensating means will result in a landing distance not more than that
with each engine operating.
SC23.77 Balked landing.
Instead of compliance with Sec. 23.77, the following apply:
In the landing configuration, the steady gradient of climb may not
be less than 3.2 percent with the following:
(a) The engines at the power or thrust that is available eight
seconds after initiation of movement of the power or thrust controls
from the minimum flight idle to the inflight takeoff position; and
(b) A climb speed of not more than VREF, as defined in
Sec. 23.73(b).
SC23.145 Longitudinal control.
In Sec. 23.145(c), change the reference from ``Sec. 23.251'' to
``special condition SC23.251.''
SC23.149 Minimum control speed.
In Sec. 23.149(c), change the reference from ``Sec. 23.75'' to
``special condition SC23.75.''
Delete Sec. 23.149(d).
In Sec. 23.149(f), delete ``At the option of the applicant, to
comply with the requirements of Sec. 23.51(c)(1), VMCG may
be determined.''
SC23.153 Control during landings.
In Sec. 23.153(c), change the reference from ``Sec. 23.75'' to
``special condition SC23.75.''
SC23.161 Trim.
Instead of compliance with Sec. 23.161, the following apply:
(a) General. Each airplane must meet the trim requirements of this
special condition after being trimmed, and without further pressure
upon or movement of the primary controls or their corresponding trim
controls by the pilot or the automatic pilot.
(b) Lateral and directional trim. The airplane must maintain
lateral and directional trim with the most adverse lateral displacement
of the center of gravity within the relevant operating limitations
during normally expected conditions of operation (including operation
at any speed from 1.4 VS1 to VMO/MMO).
(c) Longitudinal trim. The airplane must maintain longitudinal trim
during the following:
(1) A climb with maximum continuous power at a speed not more than
1.4 VS1, with the landing gear retracted, and the flaps in
the following positions:
(i) Retracted, and
(ii) In the takeoff position.
[[Page 58666]]
(2) A power approach with a 3 degree angle of descent, the landing
gear extended, and with the following:
(i) The wing flaps retracted and at a speed of 1.4 VS1;
and
(ii) The applicable airspeed and flap position used in showing
compliance with special condition SC23.75.
(3) Level flight at any speed from 1.4 VS1 to
VMO/MMO with the landing gear and flaps
retracted, and from 1.4 VS1 to VLE with the
landing gear extended.
(d) Longitudinal, directional, and lateral trim. The airplane must
maintain longitudinal, directional, and lateral trim (for the lateral
trim, the angle of bank may not exceed five degrees) at 1.4
VS1 during climbing flight with the following:
(1) The critical engine inoperative;
(2) The remaining engine at maximum continuous power or thrust; and
(3) The landing gear and flaps retracted.
SC23.171 [Stability] General.
In Sec. 23.171, change reference from ``Secs. 23.173 through
23.181'' to ``special conditions SC23.173, SC23.175, SC23.177,
SC23.181, and Sec. 23.181.''
SC23.173 Static longitudinal stability.
Instead of compliance with Sec. 23.173, the following apply:
Under the conditions specified in special condition SC23.175, the
characteristics of the elevator control forces (including friction)
must be as follows:
(a) A pull must be required to obtain and maintain speeds below the
specified trim speed, and a push must be required to obtain and
maintain speeds above the specified trim speed. This must be shown at
any speed that can be obtained except speeds higher than the landing
gear or wing flap operating limit speeds or VFC/
MFC, whichever is appropriate, or lower than the minimum
speed for steady unstalled flight.
(b) The airspeed must return to within 10 percent of the original
trim speed for the climb, approach, and landing conditions specified in
special condition SC23.175, paragraph (a), (c), and (d), and must
return to within 7.5 percent of the original trim speed for the
cruising condition specified in special condition SC23.175, paragraph
(b), when the control force is slowly released from any speed within
the range specified in paragraph (a) of this special condition.
(c) The average gradient of the stable slope of the stick force
versus speed curve may not be less than 1 pound for each 6 knots.
(d) Within the free return speed range specified in paragraph (b)
of this special condition, it is permissible for the airplane, without
control forces, to stabilize on speeds above or below the desired trim
speeds if exceptional attention on the part of the pilot is not
required to return to and maintain the desired trim speed and altitude.
SC23.175 Demonstration of static longitudinal stability.
Instead of compliance with Sec. 23.175, static longitudinal
stability must be shown as follows:
(a) Climb. The stick force curve must have a stable slope at speeds
between 85 and 115 percent of the speed at which the airplane--
(1) Is trimmed, with--
(i) Wing flaps retracted;
(ii) Landing gear retracted;
(iii) Maximum takeoff weight; and
(iv) The maximum power or thrust selected by the applicant as an
operating limitation for use during climb; and
(2) Is trimmed at the speed for best rate of climb except that the
speed need not be less than 1.4 VS1
(b) Cruise. Static longitudinal stability must be shown in the
cruise condition as follows:
(1) With the landing gear retracted at high speed, the stick force
curve must have a stable slope at all speeds within a range which is
the greater of 15 percent of the trim speed plus the resulting free
return speed range, or 50 knots plus the resulting free return speed
range, above and below the trim speed (except that the speed range need
not include speeds less than 1.4 VS1, nor speeds greater
than VFC/MFC, nor speeds that require a stick
force of more than 50 pounds), with--
(i) The wing flaps retracted;
(ii) The center of gravity in the most adverse position;
(iii) The most critical weight between the maximum takeoff and
maximum landing weights;
(iv) The maximum cruising power selected by the applicant as an
operating limitation, except that the power need not exceed that
required at VMO/MMO; and
(v) The airplane trimmed for level flight with the power required
in paragraph (b)(1)(iv) of this special condition.
(2) With the landing gear retracted at low speed, the stick force
curve must have a stable slope at all speeds within a range which is
the greater of 15 percent of the trim speed plus the resulting free
return speed range, or 50 knots plus the resulting free return speed
range, above and below the trim speed (except that the speed range need
not include speeds less than 1.4 VS1, nor speeds greater
than the minimum speed of the applicable speed range prescribed in
paragraph (b)(1), nor speeds that require a stick force of more than 50
pounds), with--
(i) Wing flaps, center of gravity position, and weight as specified
in paragraph (b)(1) of this special condition;
(ii) Power required for level flight at a speed equal to
(VMO + 1.4 VS1)/2; and
(iii) The airplane trimmed for level flight with the power required
in paragraph (b)(2)(ii) of this special condition.
(3) With the landing gear extended, the stick force curve must have
a stable slope at all speeds within a range which is the greater of 15
percent of the trim speed plus the resulting free return speed range,
or 50 knots plus the resulting free return speed range, above and below
the trim speed (except that the speed range need not include speeds
less than 1.4 VS1, nor speeds greater than VLE,
nor speeds that require a stick force of more than 50 pounds), with--
(i) Wing flap, center of gravity position, and weight as specified
in paragraph (b)(1) of this section;
(ii) The maximum cruising power selected by the applicant as an
operating limitation, except that the power need not exceed that
required for level flight at VLE; and
(iii) The aircraft trimmed for level flight with the power required
in paragraph (b)(3)(ii) of this section.
(c) Approach. The stick force curve must have a stable slope at
speeds between 1.1 VS1 and 1.8 VS1, with--
(1) Wing flaps in the approach position;
(2) Landing gear retracted;
(3) Maximum landing weight; and
(4) The airplane trimmed at 1.4 VS1 with enough power to
maintain level flight at this speed.
(d) Landing. The stick force curve must have a stable slope, and
the stick force may not exceed 80 pounds, at speeds between 1.1
VS0 and 1.8 VS0 with--
(1) Wing flaps in the landing position;
(2) Landing gear extended;
(3) Maximum landing weight;
(4) Power or thrust off on the engines; and
(5) The airplane trimmed at 1.4 VS0 with power or thrust
off.
SC23.177 Static directional and lateral stability.
Instead of compliance with Sec. 23.177, the following apply:
(a) The static directional stability (as shown by the tendency to
recover from a skid with the rudder free) must be positive for any
landing gear and flap position, and it must be positive for any
[[Page 58667]]
symmetrical power condition to speeds from 1.2 VS1 up to
VFE, VLE, or VFC/MFC (as
appropriate).
(b) The static lateral stability (as shown by the tendency to raise
the low wing in a sideslip with the aileron controls free and for any
landing gear position and flap position, and for any symmetrical power
conditions) may not be negative at any airspeed (except speeds higher
than VFE or VLE, when appropriate) in the
following airspeed ranges:
(1) From 1.2 VS1 to VMO/MMO.
(2) From VMO/MMO to VFC/
MFC, unless the Administrator finds that the divergence is--
(i) Gradual;
(ii) Easily recognizable by the pilot; and
(iii) Easily controllable by the pilot.
(c) In straight, steady, sideslips (unaccelerated forward slips)
the aileron and rudder control movement and forces must be
substantially proportional to the angle of the sideslip. The factor of
proportionality must lie between limits found necessary for safe
operation throughout the range of sideslip angles appropriate to the
operation of the airplane. At greater angles, up to the angle at which
full rudder control is used or when a rudder pedal force of 180 pounds
is obtained, the rudder pedal forces may not reverse and increased
rudder deflection must produce increased angles of sideslip. Unless the
airplane has a yaw indicator, there must be enough bank accompanying
sideslipping to clearly indicate any departure from steady unyawed
flight.
SC23.181 Dynamic stability.
In Sec. 23.181(d), change the reference from Sec. 23.175 to
SC23.175.
SC23.201 Wings level stall.
In Sec. 23.201 (c), change the reference from ``Sec. 23.49'' to
``Sec. 23.49 and special condition SC23.49.''
Instead of compliance with Sec. 23.201 (d) and (e), the following
apply:
(d) The roll occurring between the stall and the completion of the
recovery may not exceed approximately 20 degrees.
(e) Compliance with the requirements of this section must be shown
with:
(1) Power--
(i) Off; and
(ii) The thrust necessary to maintain level flight at 1.6
VS1 (where VS1 corresponds to the stalling speed
with flaps in the approach position, the landing gear retracted, and
maximum landing weight).
(2) Flaps and landing gear in any likely combination of positions.
(3) Trim at 1.4 VS1 or at the minimum trim speed,
whichever is higher.
(4) Representative weights within the range for which certification
is requested.
(5) The most adverse center of gravity for recovery.
SC23.203 Turning flight and accelerated turning stalls.
Instead of compliance with Sec. 23.203(c), the following apply:
(c) Compliance with the requirements of this section must be shown
with:
(1) The thrust necessary to maintain level flight at 1.6
VS1 (where VS1 corresponds to the stalling speed
with flaps in the approach position, the landing gear retracted, and
maximum landing weight).
(2) Flaps and landing gear in any likely combination of positions.
(3) Trim at 1.4 VS1 or at the minimum trim speed,
whichever is higher.
(4) Representative weights within the range for which certification
is requested.
(5) The most adverse center of gravity for recovery.
SC23.207 Stall warning.
Instead of compliance with Sec. 23.207(c), the following applies:
(c) During the stall tests required by Sec. 23.201(b) and
Sec. 23.203(a)(1), the stall warning must begin at a speed exceeding
the stalling speed by seven percent or at any lesser margin if the
stall warning has enough clarity, duration, distinctiveness, or similar
properties.
SC23.251 Vibration and buffeting.
Instead of compliance with Sec. 23.251, the following apply:
(a) The airplane must be designed to withstand any vibration and
buffeting that might occur in any likely operating condition. This must
be shown by calculations, resonance tests, or other tests found
necessary by the Administrator.
(b) Each part of the airplane must be shown in flight to be free
from excessive vibration, under any appropriate speed and power
conditions up to VDF/MDF. The maximum speeds
shown must be used in establishing the operating limitations of the
airplane in accordance with special condition SC23.1581.
(c) Except as provided in paragraph (d) of this special condition,
there may be no buffeting condition in normal flight, including
configuration changes during cruise, severe enough to interfere with
the control of the airplane, to cause excessive fatigue to the
flightcrew, or to cause structural damage. Stall warning buffeting
within these limits is allowable.
(d) There may be no perceptible buffeting condition in the cruise
configuration in straight flight at any speed up to VMO/
MMO, except that stall warning buffeting is allowable.
(e) With the airplane in the cruise configuration, the positive
maneuvering load factors at which the onset of perceptible buffeting
occurs must be determined for the ranges of airspeed or Mach Number,
weight, and altitude for which the airplane is to be certified. The
envelopes of load factor, speed, altitude, and weight must provide a
sufficient range of speeds and load factors for normal operations.
Probable inadvertent excursions beyond the boundaries of the buffet
onset envelopes may not result in unsafe conditions.
SC23.253 High speed characteristics.
Instead of compliance with Sec. 23.253, the following apply:
(a) Speed increase and recovery characteristics. The following
speed increase and recovery characteristics must be met:
(1) Operating conditions and characteristics likely to cause
inadvertent speed increases (including upsets in pitch and roll) must
be simulated with the airplane trimmed at any likely cruise speed up to
VMO/MMO. These conditions and characteristics
include gust upsets, inadvertent control movements, low stick force
gradient in relation to control friction, passenger movement, leveling
off from climb, and descent from Mach to airspeed limit altitudes.
(2) Allowing for pilot reaction time after effective inherent or
artificial speed warning occurs, it must be shown that the airplane can
be recovered to a normal attitude and its speed reduced to
VMO/MMO without the following:
(i) Exceptional piloting strength or skill;
(ii) Exceeding VD/MD, or VDF/
MDF, or the structural limitations; and
(iii) Buffeting that would impair the pilot's ability to read the
instruments or control the airplane for recovery.
(3) There may be no control reversal about any axis at any speed up
to VDF/MDF with the airplane trimmed at
VMO/MMO. Any tendency of the airplane to pitch,
roll, or yaw must be mild and readily controllable, using normal
piloting techniques. When the airplane is trimmed at VMO/
MMO, the slope of the elevator control force versus speed
curve need not be stable at speeds greater than VFC/
MFC, but there must be a push force at all speeds up to
VDF/MDF and there must be no sudden or excessive
reduction of elevator control force as VDF/MDF is
reached.
[[Page 58668]]
(b) Maximum speed for stability characteristics. VFC/
MFC. VFC/MFC is the maximum speed at
which the requirements of special conditions SC23.173, SC23.175,
SC23.177, SC23.181 and Sec. 23.181 must be met with the flaps and
landing gear retracted. It may not be less than a speed midway between
VMO/MMO and VDF/MDF except
that, for altitudes where Mach number is the limiting factor,
MFC need not exceed the Mach number at which effective speed
warning occurs.
SC23.255 Out-of-trim characteristics.
In the absence of specific requirements for out-of-trim
characteristics, the Raytheon Model 390 must comply with the following:
(a) From an initial condition with the airplane trimmed at cruise
speeds up to VMO/MMO, the airplane must have
satisfactory maneuvering stability and controllability with the degree
of out-of-trim in both the airplane nose-up and nose-down directions,
which results from the greater of the following:
(1) A three-second movement of the longitudinal trim system at its
normal rate for the particular flight condition with no aerodynamic
load (or an equivalent degree of trim for airplanes that do not have a
power-operated trim system), except as limited by stops in the trim
system, including those required by Sec. 23.655(b) for adjustable
stabilizers; or
(2) The maximum mis-trim that can be sustained by the autopilot
while maintaining level flight in the high speed cruising condition.
(b) In the out-of-trim condition specified in paragraph (a) of this
special condition, when the normal acceleration is varied from +l g to
the positive and negative values specified in paragraph (c) of this
special condition, the following apply:
(1) The stick force versus g curve must have a positive slope at
any speed up to and including VFC/MFC; and
(2) At speeds between VFC/MFC and
VDF/MDF, the direction of the primary
longitudinal control force may not reverse.
(c) Except as provided in paragraph (d) and (e) of this special
condition, compliance with the provisions of paragraph (a) of this
special condition must be demonstrated in flight over the acceleration
range as follows:
(1) -1 g to +2.5 g; or
(2) 0 g to 2.0 g, and extrapolating by an acceptable method to -1 g
and +2.5 g.
(d) If the procedure set forth in paragraph (c)(2) of this special
condition is used to demonstrate compliance and marginal conditions
exist during flight test with regard to reversal of primary
longitudinal control force, flight tests must be accomplished from the
normal acceleration at which a marginal condition is found to exist to
the applicable limit specified in paragraph (b)(1) of this special
condition.
(e) During flight tests required by paragraph (a) of this special
condition, the limit maneuvering load factors, prescribed in
Secs. 23.333(b) and 23.337, need not be exceeded. Also, the maneuvering
load factors associated with probable inadvertent excursions beyond the
boundaries of the buffet onset envelopes determined under special
condition SC23.251(e), need not be exceeded. In addition, the entry
speeds for flight test demonstrations at normal acceleration values
less than 1g must be limited to the extent necessary to accomplish a
recovery without exceeding VDF/MDF.
(f) In the out-of-trim condition specified in paragraph (a) of this
special condition, it must be possible from an overspeed condition at
VDF/MDF to produce at least 1.5 g for recovery by
applying not more than 125 pounds of longitudinal control force using
either the primary longitudinal control alone or the primary
longitudinal control and the longitudinal trim system. If the
longitudinal trim is used to assist in producing the required load
factor, it must be shown at VDF/MDF that the
longitudinal trim can be actuated in the airplane nose-up direction
with the primary surface loaded to correspond to the least of the
following airplane nose-up control forces:
(1) The maximum control forces expected in service, as specified in
Secs. 23.301 and 23.397.
(2) The control force required to produce 1.5 g.
(3) The control force corresponding to buffeting or other phenomena
of such intensity that is a strong deterrent to further application of
primary longitudinal control force.
SC23.629 Flutter.
Instead of the term/speed ``VD'' in Sec. 23.629(b), use
``VDF/MDF.''
SC23.703 Takeoff warning system.
In the absence of specific requirements for a takeoff warning
system, the following apply:
Unless it can be shown that a lift or longitudinal trim device that
affects the takeoff performance of the aircraft would not give an
unsafe takeoff configuration when selected out of an approved takeoff
position, a takeoff warning system must be installed and meet the
following requirements:
(a) The system must provide to the pilots an aural warning that is
automatically activated during the initial portion of the takeoff roll
if the airplane is in a configuration that would not allow a safe
takeoff. The warning must continue until--
(1) The configuration is changed to allow safe takeoff, or
(2) Action is taken by the pilot to abandon the takeoff roll.
(b) The means used to activate the system must function properly
for all authorized takeoff power settings and procedures and throughout
the ranges of takeoff weights, altitudes, and temperatures for which
certification is requested.
SC23.1195 Engine Fire Extinguishing System.
(a) Fire extinguishing systems must be installed and compliance
must be shown with the following:
(1) Except for combustor, turbine, and tailpipe sections of
turbine-engine installations that contain lines or components carrying
flammable fluids for which a fire originating in these sections can be
controllable, a fire extinguisher system must serve each engine
compartment.
(2) The fire extinguishing system, the quantity of the
extinguishing agent, the rate of discharge, and the discharge
distribution must be adequate to extinguish fires.
(3) The fire extinguishing system for a nacelle must be able to
simultaneously protect each compartment of the nacelle for which
protection is provided.
(b) Fire extinguishing agents must meet the following requirements:
(1) Be capable of extinguishing flames emanating from any burning
of fluids or other combustible materials in the area protected by the
fire extinguishing system;
(2) Have thermal stability over the temperature range likely to be
experienced in the compartment in which they are stored; and
(3) If any toxic extinguishing agent is used, provisions must be
made to prevent harmful concentrations of fluid or fluid vapors from
entering any personnel compartment even though a defect may exist in
the extinguishing system. This must be shown by test except for built-
in carbon dioxide fuselage compartment fire extinguishing systems for
which:
(i) Five pounds or less of carbon dioxide will be discharged, under
established fire control procedures, into any fuselage compartment; or
(ii) Protective breathing equipment is available for each flight
crew member on flight deck duty.
[[Page 58669]]
(c) Fire extinguishing agent containers must meet the following
requirements:
(1) Each extinguishing agent container must have a pressure relief
to prevent bursting of the container by excessive internal pressures.
(2) The discharge end of each discharge line from a pressure relief
connection must be located so the discharge of the fire extinguishing
agent would not damage the airplane. The line must also be located or
protected to prevent clogging caused by ice or other foreign matter.
(3) A means must be provided for each fire extinguishing agent
container to indicate that the container has discharged or that the
charging pressure is below the established minimum necessary for proper
functioning.
(4) The temperature of each container must be maintained, under
intended operating conditions, to prevent the pressure in the container
from falling below that necessary to provide an adequate rate of
discharge, or rising high enough to cause premature discharge.
(5) If a pyrotechnic capsule is used to discharge the fire
extinguishing agent, each container must be installed so that
temperature conditions will not cause hazardous deterioration of the
pyrotechnic capsule.
(d) Fire extinguisher system materials must meet the following
requirements:
(1) No material in any fire extinguishing system may react
chemically with any extinguishing agent so as to create a hazard; and
(2) Each system component in an engine compartment must be
fireproof.
SC23.1323 Airspeed indicating system.
In addition to the requirements of Sec. 23.1323, the following
apply:
(a) The airspeed indicating system must be calibrated to determine
the system error in flight and during the accelerate-takeoff ground
run. The ground run calibration must be determined as follows:
(1) From 0.8 of the minimum value of V1 to the maximum
value of V2, considering the approved ranges of altitude and
weight; and
(2) With the flaps and power settings corresponding to the values
determined in the establishment of the takeoff path under special
condition SC23.57, assuming that the critical engine fails at the
minimum value of V1.
(b) The information showing the relationship between IAS and CAS,
determined in accordance with paragraph (a) of this special condition,
must be shown in the Airplane Flight Manual.
SC23.1325 Static pressure system.
In addition to the requirements of Sec. 23.1325, the following
apply:
(a) The altimeter system calibration required by Sec. 23.1325(e)
must be shown in the Airplane Flight Manual.
(b) If an altimeter system is fitted with a device that provides
corrections to the altimeter indication, the device must be designed
and installed in such manner that it can be by-passed when it
malfunctions, unless an alternate altimeter system is provided. Each
correction device must be fitted with a means for indicating the
occurrence of reasonably probable malfunctions, including power
failure, to the flightcrew. The indicating means must be effective for
any cockpit lighting condition likely to occur.
SC23.1501 [Operating Limitations and Information] General.
Instead of the requirements of Sec. 23.1501(a), the following
apply:
(a) Each operating limitation specified in Secs. 23.1505 through
23.1522, 23.1524 through 23.1527 and special conditions SC23.1505,
SC23.1513, and SC23.1523.
SC23.1505 Airspeed limitations.
In Sec. 23.1505(a)(2)(ii), change the reference from
``Sec. 23.251'' to ``special condition SC23.251.''
Instead of compliance with Sec. 23.1505(c), the following applies:
The maximum operating limit speed (VMO/MMO
airspeed or Mach number, whichever is critical at a particular
altitude) is a speed that may not be deliberately exceeded in any
regime of flight (climb, cruise, or descent), unless a higher speed is
authorized for flight test or pilot training operations.
VMO/MMO must be established so that it is not
greater than the design cruising speed, VC, and so that it
is sufficiently below VD/MD, or VDF/
MDF, to make it highly improbable that the latter speeds
will be inadvertently exceeded in operations. The speed margin between
VMO/MMO and VD/MD, or
VDF/MDF, may not be less than that determined
under Sec. 23.335(b) or found necessary during the flight tests
conducted under special condition SC23.253.
SC23.1513 Minimum control speed.
In Sec. 23.1513, change the reference from ``Sec. 23.149'' to
``Sec. 23.149 and special condition SC23.149.''
SC23.1523 Minimum flightcrew.
Instead of compliance with Sec. 23.1523, the following apply:
The minimum flightcrew must be established so that it is sufficient
for safe operation considering:
(a) The workload on individual flightcrew members and each
flightcrew member workload determination must consider the following:
(1) Flight path control,
(2) Collision avoidance,
(3) Navigation,
(4) Communications,
(5) Operation and monitoring of all essential airplane systems,
(6) Command decisions, and
(7) The accessibility and ease of operation of necessary controls
by the appropriate flightcrew member during all normal and emergency
operations when at the flightcrew member station.
(b) The accessibility and ease of operation of necessary controls
by the appropriate flightcrew member; and
(c) The kinds of operation authorized under Sec. 23.1525.
SC23.1541 [Markings and Placards] General.
Instead of Sec. 23.1541(a)(1), the following applies:
(a)(1) The markings and placards specified in Secs. 23.1545 to
23.1567 and special condition SC23.1545; and
SC23.1545 Airspeed indicator.
In Sec. 23.1545(d), change the reference from ``Sec. 23.1505(c)''
to ``special condition SC23.1505.''
SC23.1581 [Airplane Flight Manual and Approved Manual Material.]
General.
In Sec. 23.1581 replace references to Sec. 23.1583, Sec. 23.1585,
and Sec. 23.1587 with special conditions SC23.1583, SC23.1585, and
SC23.1587, respectively.
SC23.1583 Operating limitations.
Instead of the requirements of Sec. 23.1583, the following apply:
(a) Airspeed limitations. The following airspeed limitations and
any other airspeed limitations necessary for safe operation must be
furnished:
(1) The maximum operating limit speed, VMO/
MMO, and a statement that this speed limit may not be
deliberately exceeded in any regime of flight (climb, cruise, or
descent) unless a higher speed is authorized for flight test or pilot
training.
(2) If an airspeed limitation is based upon compressibility
effects, a statement to this effect and information as to any symptoms,
the probable behavior of the airplane, and the recommended recovery
procedures.
(3) The maneuvering speed, VO, and a statement that full
application of rudder and aileron controls, as well as maneuvers that
involve angles of attack near the stall, should be confined to speeds
below this value.
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(4) The maximum speed for flap extension, VFE, for the
takeoff, approach, and landing positions.
(5) The landing gear operating speed or speeds, VLO.
(6) The landing gear extended speed, VLE if greater than
VLO, and a statement that this is the maximum speed at which
the airplane can be safely flown with the landing gear extended.
(b) Powerplant limitations. The following information must be
furnished:
(1) Limitations required by Sec. 23.1521.
(2) Explanation of the limitations, when appropriate.
(3) Information necessary for marking the instruments, required by
Sec. 23.1549 through Sec. 23.1553.
(c) Weight and loading distribution. The weight and extreme forward
and aft center of gravity limits required by Secs. 23.23 and 23.25 must
be furnished in the Airplane Flight Manual. In addition, all of the
following information and the information required by Sec. 23.1589 must
be presented either in the Airplane Flight Manual or in a separate
weight and balance control and loading document, which is incorporated
by reference in the Airplane Flight Manual:
(1) The condition of the airplane and the items included in the
empty weight, as defined in accordance with Sec. 23.29.
(2) Loading instructions necessary to ensure loading of the
airplane within the weight and center of gravity limits, and to
maintain the loading within these limits in flight.
(d) Maneuvers. A statement that acrobatic maneuvers, including
spins, are not authorized.
(e) Maneuvering flight load factors. The positive maneuvering limit
load factors for which the structure is proven, described in terms of
accelerations, and a statement that these accelerations limit the angle
of bank in turns and limit the severity of pull-up maneuvers must be
furnished.
(f) Flightcrew. The number and functions of the minimum flightcrew
must be furnished.
(g) Kinds of operation. The kinds of operation (such as VFR, IFR,
day, or night) and the meteorological conditions in which the airplane
may or may not be used must be furnished. Any installed equipment that
affects any operating limitation must be listed and identified as to
operational function.
(h) Additional operating limitations must be established as
follows:
(1) The maximum takeoff weights must be established as the weights
at which compliance is shown with the applicable provisions of part 23
(including the takeoff climb provisions of special condition SC23.67(a)
through (c) for altitudes and ambient temperatures).
(2) The maximum landing weights must be established as the weights
at which compliance is shown with the applicable provisions of part 23
(including the approach climb and balked landing climb provisions of
special conditions SC23.67(d) and SC23.77 for altitudes and ambient
temperatures).
(3) The minimum takeoff distances must be established as the
distances at which compliance is shown with the applicable provisions
of part 23 (including the provisions of special conditions SC23.55 and
SC23.59 for weights, altitudes, temperatures, wind components, and
runway gradients).
(4) The extremes for variable factors (such as altitude,
temperature, wind, and runway gradients) are those at which compliance
with the applicable provision of part 23 and these special conditions
is shown.
(i) Maximum operating altitude. The maximum altitude established
under Sec. 23.1527 must be furnished.
(j) Maximum passenger seating configuration. The maximum passenger
seating configuration must be furnished.
(k) Maximum operating temperature. The maximum operating
temperature established under Sec. 23.1521 must be furnished.
SC23.1585 Operating procedures.
Instead of the requirements of Sec. 23.1585, the following applies:
(a) Information and instruction regarding the peculiarities of
normal operations (including starting and warming the engines, taxiing,
operation of wing flaps, slats, landing gear, speed brake, and the
automatic pilot) must be furnished, together with recommended
procedures for the following:
(1) Engine failure (including minimum speeds, trim, operation of
the remaining engine, and operation of flaps);
(2) Restarting turbine engines in flight (including the effects of
altitude);
(3) Fire, decompression, and similar emergencies;
(4) Use of ice protection equipment;
(5) Operation in turbulence (including recommended turbulence
penetration airspeeds, flight peculiarities, and special control
instructions);
(6) Procedures for transition from landing approach to balk landing
climb; and
(7) The demonstrated crosswind velocity and procedures and
information pertinent to operation of the airplane in crosswinds.
(b) Information identifying each operating condition in which the
fuel system independence prescribed in Sec. 23.953 is necessary for
safety must be furnished, together with instructions for placing the
fuel system in a configuration used to show compliance with that
section.
(c) For each airplane showing compliance with Sec. 23.1353(g)(2) or
(g)(3), the operating procedures for disconnecting the battery from its
charging source must be furnished.
(d) If the unusable fuel supply in any tank exceeds 5 percent of
the tank capacity, or 1 gallon, whichever is greater, information must
be furnished indicating that, when the fuel quantity indicator reads
``zero'' in level flight, any fuel remaining in the fuel tank cannot be
used safely in flight.
(e) Information on the total quantity of usable fuel for each fuel
tank must be furnished.
(f) The buffet onset envelopes determined under special condition
SC23.251 must be furnished. The buffet onset envelopes presented may
reflect the center of gravity at which the airplane is normally loaded
during cruise if corrections for the effect of different center of
gravity locations are furnished.
SC23.1587 Performance information.
Instead of the requirements of Sec. 23.1587, the following applies:
(a) Each Airplane Flight Manual must contain information to permit
conversion of the indicated temperature to free air temperature if
other than a free air temperature indicator is used to comply with the
requirements of Sec. 23.1303(d).
(b) Each Airplane Flight Manual must contain the performance
information computed under the applicable provisions of this part for
the weights, altitudes, temperatures, wind components, and runway
gradients, as applicable, within the operational limits of the
airplane, and must contain the following:
(1) The conditions under which the performance information was
obtained, including the speeds associated with the performance
information.
(2) VS determined in accordance with special condition
SC23.49.
(3) The following performance information (determined by
extrapolation and computed for the range of weights between the maximum
landing and maximum takeoff weights):
(i) Climb in the landing configuration.
(ii) Climb in the approach configuration.
(iii) Landing distance.
(4) Procedures established under special condition SC23.45(d), (e),
and (f) that are related to the limitations and
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information required by special condition SC23.1583(h) and by this
paragraph. These procedures must be in the form of guidance material,
including any relevant limitations or information.
(5) An explanation of significant or unusual flight or ground
handling characteristics of the airplane.
SC23.A Effects of contamination on natural laminar flow airfoils.
In the absence of specific requirements for airfoil contamination,
airplane airfoil designs that have airfoil pressure gradient
characteristics and smooth aerodynamic surfaces that may be capable of
supporting natural laminar flow must comply with the following:
(a) It must be shown by tests, or analysis supported by tests, that
the airplane complies with the requirements of Secs. 23.141 through
23.207, 23.233, 23.251, 23.253 (and any changes made to these
paragraphs by these special conditions) with any airfoil contamination
that would normally be encountered in service and that would cause
significant adverse effects on the handling qualities of the airplanes
resulting from the loss of laminar flow.
(b) Significant performance degradations identified as resulting
from the loss of laminar flow must be provided as part of the
information required by special conditions SC23.1585 and SC23.1587.
Issued in Kansas City, Missouri on October 11, 1998.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 98-29301 Filed 10-30-98; 8:45 am]
BILLING CODE 4910-13-U