[Federal Register Volume 61, Number 12 (Thursday, January 18, 1996)]
[Proposed Rules]
[Pages 1260-1268]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-415]
[[Page 1259]]
_______________________________________________________________________
Part II
Department of Transportation
_______________________________________________________________________
Federal Aviation Administration
_______________________________________________________________________
14 CFR Part 1, et al.
1-g Stall Speed as the Basis for Compliance With Part 25 of the Federal
Aviation Regulations; Proposed Rule
Federal Register / Vol. 61, No. 12 / Thursday, January 18, 1996 /
Proposed Rules
[[Page 1260]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Parts 1, 25, 36, and 97
[Docket No. 28404; Notice No. 95-17]
RIN 2120-AD40
1-g Stall Speed as the Basis for Compliance With Part 25 of the
Federal Aviation Regulations
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking.
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SUMMARY: The Federal Aviation Administration (FAA) proposes to redefine
the reference stall speed for transport category airplanes as the 1-g
stall speed instead of the minimum speed obtained in a stalling
maneuver. The proposed changes would: provide for a consistent,
repeatable reference stall speed; ensure consistent and dependable
maneuvering margins; provide for adjusted multiplying factors to
maintain approximately the current requirements in areas where use of
the minimum speed in the stalling maneuver has proven adequate; and
harmonize the applicable regulations with those proposed for the
European Joint Aviation Requirements-25 (JAR-25). These changes would
result in a higher level of safety for those cases in which current
methods would result in artificially low operating speeds.
DATES: Comments must be received on or before May 17, 1996.
ADDRESSES: Comments on this notice may be mailed in triplicate to:
Federal Aviation Administration, Office of the Chief Counsel,
Attention: Rules Docket (AGC-10), Docket No. 28404, 800 Independence
Avenue SW., Washington, DC 20591; or delivered in triplicate to: Room
915G, 800 Independence Avenue SW., Washington, DC 20591. Comments
delivered must be marked Docket No. 28404. Comments may be examined in
Room 915G weekdays, except Federal holidays, between 8:30 a.m. and 5:00
p.m. In addition, the FAA is maintaining an information docket of
comments in the Transport Airplane Directorate (ANM-100), Federal
Aviation Administration, Northwest Mountain Region, 1601 Lind Avenue
SW., Renton, WA 98055-4056. Comments in the information docket may be
examined weekdays, except Federal holidays, between 7:30 a.m. and 4:00
p.m.
FOR FURTHER INFORMATION CONTACT: Don Stimson, Flight Test and Systems
Branch, ANM-111, Transport Airplane Directorate, Aircraft Certification
Service, FAA, 1601 Lind Avenue SW., Renton, WA 98055-4056; telephone
(206) 227-1129; facsimile (206) 227-1320.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in this proposed
rulemaking by submitting such written data, views, or arguments as they
may desire. Comments relating to any environmental, energy, or economic
impact that might result from adopting the proposals contained in this
notice are invited. Substantive comments should be accompanied by cost
estimates. Commenters should identify the regulatory docket or notice
number and submit comments in triplicate to the Rules Docket address
above. All comments received on or before the closing date for comments
will be considered by the Administrator before taking action on this
proposed rulemaking. The proposals contained in this notice may be
changed in light of comments received. All comments received will be
available in the Rules Docket, both before and after the comment period
closing date, for examination by interested persons. 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 must submit with those
comments a self-addressed, stamped postcard on which the following
statement is made: ``Comments to Docket No. 28404.'' The postcard will
be date stamped and returned to the commenter.
Availability of the NPRM
Any person may obtain a copy of this notice by submitting a request
to the Federal Aviation Administration, Office of Public Affairs,
Attention: Public Inquiry Center, APA-230, 800 Independence Avenue SW.,
Washington, DC 20591; or by calling (202) 267-3484. The notice number
of this NPRM must be identified in all communications. Persons
interested in being placed on a mailing list for future rulemaking
documents should also request a copy of Advisory Circular No. 11-2A,
Notice of Proposed Rulemaking Distribution System, which describes the
application procedure.
Background
The stalling speed (V2) is defined as the minimum speed
demonstrated in the performance stall maneuver described in Sec. 25.103
of 14 CFR part 25 (part 25) of the Federal Aviation Regulations (FAR).
VS has historically served as a reference speed for determining
the minimum operating speeds for transport category airplanes. Examples
of minimum operating speeds that are based on VS include the
takeoff safety speed (V2), the final takeoff climb speed, and the
landing approach speed. The airworthiness standards of part 25 define
these speeds as multiples of VS. For example, V2 must be at
least 1.2 times VS, the final takeoff climb speed must be at least
1.25 times VS, and the landing approach speed must be at least 1.3
times VS.
The speed margin, or difference in speed, between VS and each
minimum operating speed provides a safety ``cushion'' to ensure that
normal operating speeds are sufficiently higher than the speed at which
the airplane stalls. Using multiplying factors applied to VS to
provide this speed margin, however, assumes that VS provides a
proper reference stall speed. Since VS is the minimum speed
obtained in the stalling maneuver, it can be less than the lowest speed
at which the airplane's weight is still supported entirely by
aerodynamic lift. If VS is significantly less than this speed,
applying multiplying factors to VS to determine the minimum
operating speeds may not provide as large a speed margin as intended.
A proper reference stall speed should provide a reasonably
consistent approximation of the wing's maximum usable lift. Maximum
usable lift occurs at the minimum speed for which the lift provided by
the wing is capable of supporting the weight of the airplane. This
speed is known as the 1-g stall speed because the load factor (the
ratio of airplane lift to weight) at this speed is equal to 1.0 ``g''
(where ``g'' is the acceleration caused by the force of gravity) in the
direction perpendicular to the flight path of the airplane. A speed
lower than the 1-g stall speed represents a transient flight condition
that, if used as a reference for the deriving minimum operating speeds,
may not provide the desired speed margin to protect against
inadvertently stalling the airplane.
For jet transport airplanes, the minimum speed obtained in the
stall maneuver of Sec. 25.103 usually occurs near the point in the
maneuver where the airplane spontaneously pitches nose-down or where
the pilot initiates recovery after reaching a deterrent level of
buffet, i.e., a vibration of a magnitude and severity that is a strong
and effective deterrent to further speed reduction. Early generation
transport airplanes, which had fairly straight
[[Page 1261]]
wings, typically pitched nose-down near the 1-g stall speed. The
minimum speed in the maneuver was easy to note and record, and served
as an adequate approximation of the speed for maximum lift.
For the recent generation of high speed transport airplanes with
swept wings, however, the minimum speed obtained in the stalling
maneuver can be substantially lower than the speed for maximum lift.
Furthermore, the point at which the airplane pitches nose down or
exhibits a deterrent level of buffet is more difficult to distinguish
and can vary with piloting technique. As a result, the minimum speed in
the stalling maneuver has become an inappropriate reference for most
modern high speed transport airplanes for establishing minimum
operating speeds since it may: (1) Be inconsistently determined, and
(2) represent a flight condition in which the load factor perpendicular
to the flight path is substantially less than 1.0 g.
In recent years, advanced technology transport category airplanes
have been developed that employ novel flight control systems. These
flight control systems incorporate unique protection features that are
intended to prevent the airplane from stalling. They also prevent the
airplane from maintaining speeds that are slower than a small
percentage above the 1-g stall speed. Because of their unique design
features, the traditional method of establishing VS as the minimum
speed obtained in the stalling maneuver was inappropriate for these
airplanes. The FAA issued special conditions for these airplanes to
define the reference stall speed as the 1-g stall speed for the flight
requirements contained in subpart B of part 25 and the noise
requirements contained in part 36 of the FAR.
In these special conditions, the multiplying factors used to
determine the minimum operating speeds were reduced in order to
maintain equivalency with acceptable operating speeds used by previous
jet transports. Since the 1-g stall speed is generally higher than the
minimum speed obtained in the stalling maneuver, retaining the current
multiplying factors would have resulted in higher minimum operating
speeds for airplanes using the 1-g stall speed as the reference stall
speed. However, increasing the minimum operating speeds would impose
costs on operators because payloads would have to be reduced to comply
with the regulations at the higher operating speeds. Based on the
service experience of the current fleet of jet transports, the costs
imposed would not be offset by a commensurate increase in safety.
Several airplane types with conventional flight control systems
have also been certificated using the 1-g stall speed as the reference
stall speed. Because of the potential deficiencies in using the minimum
speed demonstrated in the stalling maneuver, the FAA has been
encouraging applicants to use the 1-g stall speed in lieu of the
minimum speed obtained in the stalling maneuver. Applicants generally
desire to use 1-g stall speeds because the 1-g stall speeds are less
dependent on pilot technique and other subjective evaluations. Hence,
1-g stall speeds are easier to predict and provide a higher level of
confidence for developing predictions of overall airplane performance.
Again, reduced multiplying factors are applied to the 1-g stall speeds
to obtain minimum operational service. Using 1-g stall speeds ensures
that the airplane's minimum operating speeds will not be unreasonably
low.
Discussion of the Proposals
The FAA proposes to define the reference stall speed in Sec. 25.103
as a 1-g stall speed, rather than the minimum speed obtained in the
stalling maneuver. This action would provide a consistent basis for use
in all type design certification requirements for transport category
airplanes. The FAA proposes to introduce the symbol VSR to
represent this speed and to indicate that it is different than the
minimum speed obtained in the stalling maneuver, VS.
In addition, the FAA proposes to reduce the multiplying factors
that are used in combination with the reference stall speed to
determine the minimum operating speeds by approximately 6 percent. This
change would result in minimum operating speeds equivalent to those for
most current jet transports since the 1-g stall speed for these
airplanes is approximately 6 percent higher than the minimum speed
obtained in the stalling maneuver. Demonstrating a minimum stalling
speed more than 6 percent slower than the 1-g stall speed, which is
possible under the current standards, would provide an unacceptable
basis for determining the minimum operating speeds. The proposed
standards would prevent this situation from occurring. In this respect,
the proposed standards would provide a higher level of safety than the
existing standards.
However, the reduced factors would allow lower minimum operating
speeds to be established for those airplanes that have a minimum speed
in the stalling maneuver approximately equal to the 1-g stall speed.
One particular class of airplanes for which this applies are airplanes
equipped with devices that abruptly push the nose down (e.g., stick
pushers) near the angle of attack for maximum lift. These devices are
typically installed on airplanes with unacceptable natural stalling
characteristics. The abrupt nose down push provides an artificial stall
indication and acceptable stall characteristics, and prevents the
airplane from reaching a potentially hazardous natural aerodynamic
stall. The minimum speed obtained in this maneuver is approximately
equal to the 1-g stall speed.
Traditionally, the existing multiplying factors have been applied
to these airplanes. The proposal to define the reference stall speed as
the 1-g stall speed would not affect these airplanes, but reducing the
multiplying factors would allow lower minimum operating speeds to be
established. Therefore, this proposal would allow these airplanes to be
operated at speeds and angles-of-attack closer to the pusher activation
point than has been experienced in operational service.
The FAA considers this reduction in operating speeds for pusher-
equipped airplanes to be acceptable, provided the pusher reliably
performs its intended function and that unwanted operation is
minimized. The FAA intends to propose an acceptable method of
addressing these concerns in an upcoming revision to Advisory Circular
(AC) 25-7. In this material, the FAA will provide criteria for pusher
reliability, the effects of design and manufacturing tolerances on the
pusher activation point, design features such as phase advance and
filtering, and the affects of atmospheric turbulence and windshear.
In addition to proposing to define the reference stall speed as the
1-g stall speed and to reduce the multiplying factors for establishing
the minimum operating speeds, the FAA also proposes to require
applicants to demonstrate adequate maneuvering capability during the
takeoff climb, en route climb, and landing approach phases of flight.
During a banked turn, a portion of the lift generated by the wing
provides a force to help turn the airplane. To remain at the same
altitude, the airplane must produce additional lift. Therefore, banking
the airplane (at a constant speed and altitude) reduces the stall
margin, which is the difference between the lift required for the
maneuver and the maximum lift capability of the wing. As the bank angle
increases, the stall margin is reduced proportionately. This bank angle
effect on the stall margin can be determined analytically, and the
multiplying factors applied to VSR to
[[Page 1262]]
determine the minimum operating speeds are intended to ensure that an
adequate stall margin is maintained.
In addition to the basic effect of bank angle, however, modern wing
designs also typically exhibit a significant reduction in maximum lift
capability with increasing Mach number. The magnitude of this Mach
number effect depends on the design characteristics of the particular
wing. For wing designs with a large Mach number effect, the maximum
bank angle that can be achieved while retaining an acceptable stall
margin can be significantly reduced. Because the effect of Mach number
can be significant, and because it can also vary greatly for different
wing designs, the multiplying factors applied to VSR are
insufficient to ensure that adequate maneuvering capability exists at
the minimum operating speeds.
To address this issue, the FAA proposes to require a minimum bank
angle capability in a coordinated turn without encountering stall
warning or any other characteristic that might interfere with normal
maneuvering. This requirement would be added to Sec. 25.143 as a new
paragraph (g). The proposed minimum bank angles were derived by adding
a 15 degree allowance for wind gusts and inadvertent overshoot to a
maneuvering capability the FAA considers necessary for the specific
cases identified in the proposed new paragraph. These proposed maneuver
margin requirements are intended to ensure that the level of safety in
maneuvering flight is not reduced by the proposed change to the
reference stall speed and the reduction in the multiplying factors used
to determine the minimum operating speeds.
Consistent with the proposed maneuver margin requirements, the FAA
proposes adding Secs. 25.107(c)(3), 25.107(g)(2), and 25.125(a)(2)(iii)
to reference Sec. 25.143(g) in the list of constraints applicants must
consider when selecting the minimum takeoff safety speed, final takeoff
speed, and reference landing speeds, respectively. The normal all-
engines-operating takeoff climb speed selected by the applicant must
also provide the minimum bank angle capability specified in the
proposed Sec. 25.143(g).
Section 25.145(a) requires that there be adequate longitudinal
control available to promptly pitch the airplane's nose down from at or
near the stall in order to return to original trim speed. The intent of
this requirement is to ensure sufficient pitch control for a prompt
recovery if the airplane is inadvertently slowed to the point of stall.
The FAA proposes to change the wording of this requirement to replace
``VS'' with ``the stall,'' ``Sec. 25.103(b)(1)'' with
``Sec. 25.103(a)(6),'' and ``at any speed'' with ``at any point.''
These changes would be consistent with the proposed change to the
definition of the reference stall speed and the proposed re-formatting
of Sec. 25.103.
Although Sec. 25.145(a) must be met both with power off and with
maximum continuous power, there is no intention to require flight test
demonstrations of full stalls at engine powers above that specified in
Sec. 25.201(a)(2). Instead of performing a full stall at maximum
continuous power, compliance may be assessed by demonstrating
sufficient static longitudinal stability and nose down control margin
when the deceleration is ended at least one second past stall warning
during a one knot per second deceleration. The static longitudinal
stability during the maneuver and the nose down control power remaining
at the end of the maneuver must be sufficient to assure compliance with
the requirement.
Section 25.207 requires that a warning of an impending stall must
be provided in order to prevent the pilot from inadvertently stalling
the airplane. The warning must occur at a speed sufficiently higher
than the stall speed to allow the pilot time to take action to avoid a
stall. The speed difference between the stall speed and the speed at
which the stall warning occurs is known as the stall warning margin.
The FAA proposes amending the size of the stall warning margin required
by Sec. 25.207(c) because of the change in definition of the reference
stall speed.
Currently, the stall warning must begin at a speed exceeding
VS by seven knots, or a lesser margin if the stall warning has
enough clarity, duration, distinctiveness, or other similar properties.
Requiring the same seven knot warning margin to be provided relative to
VSR would result in an increase to the minimum operating speeds.
This increase in the minimum operating speeds would be necessary to
meet the maneuvering margin requirements proposed in Sec. 25.143(g),
which are defined relative to the stall warning speed. However, as
discussed previously, requiring an increase to the minimum operating
speeds would impose costs to airplane operators that cannot be
justified by service experience.
On the other hand, if the stall warning margin were reduced to
retain approximately the same stall warning speed, the warning would
occur only one or two knots prior to reaching the 1-g stall speed.
Although reaching the 1-g stall speed is not likely to be a
catastrophic occurrence, the FAA considers such a small stall warning
margin to be unacceptable. The FAA proposes requiring a stall warning
margin of at least 3 knots or 3 percent, whichever is greater, relative
to VSR. The FAA considers this margin to represent a reasonable
balance between providing the pilot with enough warning to avert an
impending stall, and providing adequate maneuvering capability at the
minimum operating speeds. This proposal would retain the existing level
of safety.
The FAA proposes to require a larger stall warning margin for
airplanes equipped with devices that abruptly push the nose down at a
selected angle of attack (e.g., stick pushers). Inadvertent operation
of such a device, especially close to the ground, can have more serious
consequences than a comparable situation in which the pilot of an
airplane without the device inadvertently slows to VSR. Therefore,
the FAA proposes adding Sec. 25.207(d) to require the stall warning,
for airplanes equipped with one of these devices, to occur at least 5
knots or 5 percent, whichever is greater, above the speed at which the
device activates. This proposal is intended to retain the existing
level of safety for airplanes equipped with such devices.
The FAA proposes to add a new paragraph, Sec. 25.207(e), to require
that, in a slow-down turn with load factors up to 1.5 g and
deceleration rates up to 3 knots per second, sufficient stall warning
must exist to prevent stalling when recovery is initiated not less than
one second after stall warning occurs. The FAA considers the proposed
requirement necessary to provide adequate stall warning during a
dynamic maneuver, such as a collision avoidance maneuver. In addition,
this new paragraph would provide a quantitative requirement with which
to assess whether ``sufficient margin to prevent inadvertent stalling *
* * in turning flight'' has been provided as required by
Sec. 25.207(a). This proposal would increase the level of safety during
maneuvering flight.
The FAA proposes to add a new paragraph, Sec. 25.207(f), to require
that stall warning be provided for abnormal airplane configurations
likely to be used following system failures. This proposal adds a
requirement currently contained in JAR-25 and is consistent with
current transport airplane designs. There would be no impact on the
existing level of safety.
On modern jet transports, the natural buffet or vibration caused by
the airflow separating and reattaching itself to the wing as the
airplane approaches the
[[Page 1263]]
stall speed is usually not strong enough by itself to provide an
effective stall warning. Therefore, stall warning on modern transport
category airplanes is usually provided through an artificial means,
such as a stick shaker that shakes the pilot's control column.
Production tolerances associated with these systems can result in
variations in the size of the stall warning margin for different
airplanes manufactured under the same approved type design.
The FAA considers the stall warning margins proposed in
Secs. 25.207(c) and (d) to be the minimum acceptable warning margins,
and that these margins should not be reduced by production tolerances
associated with a system added to the airplane to provide an artificial
stall warning. The FAA intends for the proposed stall warning margins
to be available at the most critical tolerance expected in production.
Applicants would be expected to demonstrate compliance with the
proposed stall warning margin either by flight testing with the stall
warning system set to its critical tolerance setting, or by adjusting
flight test data obtained at some other setting.
The tolerances associated with the stall warning system must also
be considered in relation to the proposed minimum maneuvering
requirements of Sec. 25.143(g). As proposed, Sec. 25.143(g) would
require that the airplane be capable of reaching a minimum bank angle
during a coordinated turn without encountering stall warning. Because
the proposed requirements already provide the capability to overshoot
the intended bank angle by 15 degrees, the small differences in the
speed at which the stall warning system operates due to system
tolerances are not as critical. Therefore, the FAA intends for the
minimum bank angles in the proposed Sec. 25.143(g) to apply at the
designed nominal setting of the stall warning system. To ensure that
large production tolerances do not adversely impact the airplane's
maneuvering capability free of stall warning, the bank angle capability
specified in the proposed Sec. 25.143(g) should not be reduced by more
than two degrees with the stall warning system operating at its most
critical tolerance. Applicants would be expected to demonstrate this
capability either by flight test with the system set to its critical
tolerance, or by analytically adjusting flight test data obtained at
some other setting.
To be consistent with the proposed revision of the definition of
the reference stall speed, the FAA proposes to incorporate reduced
multiplying factors throughout part 25, where appropriate, in
requirements that use speeds based on a multiple of the reference stall
speed. The FAA also proposes numerous minor wording and structural
changes to various sections to improve editorial clarity and to
harmonize with the wording and structure proposed for JAR-25.
The FAA proposes to add the nomenclature ``final takeoff speed''
and ``reference landing speed'' and the abbreviations ``VFTO'' and
``VREF'' to denote these speeds, respectively, to part 1 of the
FAR. These terms and abbreviations, which are commonly used in the
aviation industry, would be referenced throughout the proposed
amendments to part 25. The reference landing speed would be defined as
the speed of the airplane, in a specified landing configuration, at the
point where it descends through the landing screen height in the
determination of the landing distance for manual landings. The term
``landing screen height'' refers to the height of the airplane at the
beginning of the defined landing distance. This height is normally 50
feet above the landing surface (see Sec. 25.125(a)), but approvals have
been granted for steep approaches that use a landing screen height of
35 feet. The final takeoff speed would be defined as the speed of the
airplane that exists at the end of the takeoff path in the en route
configuration with one engine inoperative.
The FAA also proposes to add the abbreviations VSR, VSR0,
and VSR1 to part 1, and use them in part 25 to denote the
reference stall speed corresponding to different airplane
configurations. In addition, the FAA proposes adding the abbreviation
VSW to part 1 to refer to the stall warning speed.
The FAA proposes to amend Sec. C36.9(e)(1) by replacing ``1.3
VS + 10 knots'' with ``VREF + 10 knots'' and by removing the
words ``or the speed used in establishing the approved landing distance
under the airworthiness regulations constituting the type certification
basis of the airplane, whichever speed is greatest.'' The words
proposed to be deleted would no longer be necessary because VREF
would denote the speed used in establishing the approved landing
distance under the airworthiness regulations constituting the type
certification basis of the airplane. Also, VREF would refer to the
speed at the landing screen height, regardless of whether that speed
for a particular airplane is 1.3 VS, 1.23 VSR, or some higher
speed.
In the same manner, the FAA proposes to amend Sec. 97.3(b) by
replacing ``1.3 VS0'' with ``VREF.'' As noted above,
VREF would refer to the speed at the landing screen height used in
establishing the approved landing distance under the airworthiness
regulations constituting the type certification basis of the airplane,
regardless of whether that speed for a particular airplane is 1.3
VS, 1.23 VSR, or some higher speed.
These proposals have been discussed extensively with the European
Joint Aviation Authorities (JAA) with the intent of harmonizing the
certification requirements related to stall speed for transport
category airplanes. The JAA intend to introduce an equivalent proposal
to amend the Joint Aviation Requirements-25 (JAR-25). JAR-25 prescribes
the airworthiness standards for transport category airplanes that are
accepted by the aviation regulatory authorities of 23 European nations.
When it is published, the JAA proposal will be placed in the docket for
this rulemaking.
Regulatory Evaluation Summary
Preliminary Regulatory Evaluation, Initial Regulatory Flexibility
Determination, and Trade Impact Assessment
Proposed changes to Federal regulations must undergo several
economic analyses. First, Executive Order 12866 directs that each
Federal agency shall propose or adopt a regulation only upon a reasoned
determination that the benefits of the intended regulation justify its
costs. Second, the Regulatory Flexibility Act of 1980 requires agencies
to analyze the economic effect of regulatory changes on small entities.
Third, the Office of Management and Budget directs agencies to assess
the effects of regulatory changes on international trade. In conducting
these analyses, the FAA has determined that this proposed rule: (1)
Would generate benefits that justify its costs and is not a
``significant regulatory action'' as defined in the Executive Order;
(2) is not significant as defined in DOT's Regulatory Policies and
Procedures; (3) would not have a significant impact on a substantial
number of small entities; and (4) would not constitute a barrier to
international trade. These analyses, available in the docket, are
summarized below.
Regulatory Evaluation Summary
Costs
The proposed requirements would apply to future type certificated
transport category airplanes and generally would not impose significant
additional costs on manufacturers. One major manufacturer demonstrated
adherence to the 1-g stall speed basis in recent FAA special conditions
[[Page 1264]]
applicable to several models of advanced technology airplanes. Other
manufacturers have requested certification to the 1-g stall speed basis
through equivalent safety findings for airplanes with conventional
flight control systems.
Cost estimates provided by manufacturers generally did not vary
significantly. Data provided by a manufacturer of part 25 small
airplanes, however, showed costs several hundred thousand dollars
higher than the norm. That manufacturer estimated that short-term costs
(mostly non-recurring) to convert to the new stall speed basis would be
over $1 million and that increased costs on a program-by-program basis
would ``be substantial.'' Because of the gross nature of these
estimates and because of the inability to segment them on a per-
certification basis, they have not been incorporated into this
analysis. The FAA invites manufacturers to provide detailed cost
estimates during the public comment period.
Although several sections of part 25 would be revised by the
proposal, only five merit analysis: Sections 25.103 (Stall speed),
25.107 (Takeoff speeds), 25.125 (Landing), 25.143 (General) (under
Controllability and Maneuverability), and 25.207 (Stall warning).
Section 25.103 (Stall Speed)
The proposal to redefine the reference stall speed as a 1-g stall
speed could result in a net reduction in certification costs for part
25 large airplanes. In some recent airplane designs, manufacturers have
used the 1-g stall speed as the reference stall speed. Calculation of
the reference stall speed (VSR) is within the range of
instrumentation currently available and additional instrumentation
would not be required. Existing techniques to determine minimum speed
in the stalling maneuver require six to eight independent stalls at
various flap settings; determination of 1-g stall speed could require
approximately half as many. Cost-savings could be in the range of
$50,000 to $100,000 per type certification.
Recent part 25 small transport category airplane certifications, on
the other hand, have not been based on the 1-g stall speed.
Consequently, additional instrumentation and analysis would be
required. Incremental one-time costs for a part 25 small airplane
design would be approximately $70,000. However, cost savings
attributable to reduced testing could be realized in future
certifications (see previous paragraph re part 25 large airplanes).
Section 25.107 (Takeoff Speeds)
The proposed changes to this section, by virtue of the new
maneuvering requirements of Sec. 25.143(g), could affect airplane
operators if the proposed maneuvering requirements necessitate higher
takeoff/climb speeds and lower passenger/cargo capacity on length-
limited runways. Because of the myriad combinations of airplanes,
runways, passenger/cargo loads, etc., the FAA is unable to estimate
potential capacity limitations. The FAA invites interested parties to
provide estimates of such effects during the public comment period.
Section 25.125 (Landing)
As in the case of Sec. 25.107 above, the proposed changes to this
section could potentially affect operators by virtue of the new
maneuvering requirements in Sec. 25.143(g). Again, the FAA invites
interested parties to submit cost estimates during the public comment
period.
Section 25.143 (General)
Incremental costs that would be incurred by manufacturers to
determine minimum maneuvering margins are estimated to total
approximately $150,000 per part 25 large airplane type certification
and approximately $50,000 per part 25 small airplane type
certification.
Section 25.207 (Stall Warning)
Incremental costs that would be incurred by manufacturers to
provide sufficient stall warning at the various proposed slow-down
speeds and configurations are estimated to total approximately $120,000
per part 25 large airplane type certification and approximately
$200,000 per part 25 small airplane type certification.
Total Costs
Manufacturers of part 25 large airplanes have already incurred the
major portion of the start-up costs to convert to a 1-g stall speed
system and would therefore experience lower incremental costs than
manufacturers of part 25 small airplanes. The estimated costs to meet
the revised standards would total approximately $195,000 per part 25
large airplane type certification (costs associated with Secs. 25.143
and 25.207 reduced by the midpoint of the cost-savings range of
Sec. 25.103). Assuming 500 airplanes produced under one type
certification, this would equate to $390 per airplane.
Manufacturers of part 25 small airplanes would experience one-time
costs of $70,000 in conjunction with Sec. 25.103. In addition, costs
for each future type certification would total approximately $250,000
(attributable to Secs. 25.143 and 25.207), or about $500 per airplane
over a 500 airplane production run. A portion of these costs may be
offset by reduced testing requirements per revised Sec. 25.103. The
potential operating costs of proposed Secs. 25.107 and 25.125 have not
been estimated in this evaluation; the FAA invites interested parties
to provide cost estimates during the public comment period.
Benefits
Redefining the airplane reference stall speed as the 1-g stall
speed would result in a higher level of safety in those cases where
current methods could result in artificially low operating speeds. New
requirements for minimum maneuvering margins would assure that safe
margins are obtained at the minimum operating speeds, thus diminishing
the possibility of inadvertent stalls at critical flight stages.
A review of National Transportation Safety Board accident reports
for the years 1983-1992 does not indicate that any accidents have been
caused by inconsistent/inappropriate reference stall speeds. There were
several accidents in which inadvertent stalls were cited as a
contributing factor, but pilot error (e.g., airspeed not properly
maintained) was the probable cause rather than inherent problems with
the reference stall speed. In spite of the absence of directly aligned
accidents, the FAA postulates that, without the revisions in stall
speed as proposed or effected through special conditions, safety could
reach unacceptably low levels. The benefits associated with avoiding a
single accident would far exceed the costs of the proposed rule.
Regulatory Flexibility Determination
The Regulatory Flexibility Act of 1980 (RFA) was enacted by
Congress to insure that small entities are not unnecessarily or
disproportionately burdened by Government regulations. The RFA requires
agencies to determine whether proposed rules would have ``a significant
economic impact on a substantial number of small entities'' and, in
cases where they would, to conduct a Regulatory Flexibility Analysis.
As prescribed in implementing FAA Order 2100.14A, the size threshold
for a small aircraft manufacturer is one having 75 or fewer employees.
Since there are no manufacturers of part 25 airplanes with 75 or fewer
employees, the proposed rule would not have a significant economic
impact on a substantial number of small entities.
[[Page 1265]]
International Trade Impact Assessment
The proposed rule would not constitute a barrier to international
trade, including the export of U.S. airplanes to foreign markets and
the import of foreign airplanes into the U.S. Instead, the proposed
changes would harmonize with corresponding proposals of the European
Joint Aviation Authorities, thereby lessening restraints on trade.
Federalism Implications
The amended regulations proposed in this rulemaking would not have
substantial direct effects on the States, on the relationship between
the national government and the States, or on the distribution of power
and responsibilities among the various levels of government. Therefore,
in accordance with Executive Order 12612, it is determined that this
proposal would not have sufficient federalism implications to warrant
preparing a Federalism Assessment.
Conclusion
Because the proposed changes to redefine the reference stall speed
for transport category airplanes as the 1-g stall speed are not
expected to result in substantial economic cost, the FAA has determined
that this proposed regulation would not be significant under Executive
Order 12866. Because this is an issue which has not prompted a great
deal of public concern, the FAA has determined that this action is not
significant under DOT Regulatory Policies and Procedures (44 FR 11034,
February 25, 1979). In addition since there are no small entities
affected by this proposed rulemaking, the FAA certifies, under the
criteria of the Regulatory Flexibility Act, that this rule, if adopted,
will not have a significant economic impact, positive or negative, on a
substantial number of small entities. An initial regulatory evaluation
of the proposal, including a Regulatory Flexibility Determination and
Trade Impact Analysis, has been placed in the docket. A copy may be
obtained by contacting the person identified under FOR FURTHER
INFORMATION CONTACT.
List of Subjects
14 CFR Part 1
Air transportation.
14 CFR Part 25
Aircraft, Aviation safety, Reporting and recordkeeping
requirements.
14 CFR Part 36
Agriculture, Aircraft, Noise control.
14 CFR Part 97
Air traffic control, Airports, Navigation (air), Weather.
The Proposed Amendments
Accordingly, the Federal Aviation Administration (FAA) proposes to
amend 14 CFR parts 1, 25, 36, and 97 of the Federal Aviation
Regulations (FAR) as follows:
PART 1--DEFINITIONS AND ABBREVIATIONS
1. The authority citation for part 1 is revised to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
2. Section 1.1 is amended by adding new definitions in alphabetical
order to read as follows:
Sec. 1.1 General definitions.
* * * * *
Final takeoff speed means the speed of the airplane that exists at
the end of the takeoff path in the en route configuration with one
engine inoperative.
* * * * *
Reference landing speed means the speed of the airplane, in a
specified landing configuration, at the point where it descends through
the landing screen height in the determination of the land distance for
manual landings.
* * * * *
3. Section 1.2 is amended by adding new terms in alphabetical order
to read as follows:
Sec. 1.2 Abbreviations and symbols.
* * * * *
VFTO means final takeoff speed.
* * * * *
VREF means reference landing speed.
* * * * *
VSR means reference stall speed.
VSR0 means reference stall speed in the landing configuration.
VSR1 means reference stall speed in a specific configuration.
VSW means speed at which onset of natural or artificial stall
warning occurs.
* * * * *
PART 25--AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES
4. The authority citation for part 25 is revised to read as
follows:
Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 22704.
5. Section 25.103 is revised to read as follows:
Sec. 25.103 Stall speed.
(a) The reference stall speed, VSR, is a calibrated airspeed
as defined in paragraph (c) of this section. VSR is determined
with--
(1) Engines idling, or, if that resultant thrust causes an
appreciable decrease in stall speed, not more than zero thrust at the
stall speed;
(2) Propeller pitch controls (if applicable) in the takeoff
position;
(3) The airplane in other respects (such as flaps and landing gear)
in the condition existing in the test in which VSR is being used;
(4) The weight used when VSR is being used as a factor to
determine compliance with a required performance standard;
(5) The center of gravity position that results in the highest
value of reference stall speed; and
(6) The airplane trimmed for straight flight at a speed selected by
the applicant, but not less than 1.13 VSR and not greater than 1.3
VSR.
(b) Starting from the stabilized trim condition, apply elevator
control to decelerate the airplane so that the speed reduction does not
exceed one knot per second.
(c) The reference stall speed, VSR, is a calibrated airspeed
determined in the stalling maneuver. VSR may not be less than a 1-
g stall speed. VSR is expressed as:
[GRAPHIC][TIFF OMITTED]TP18JA96.000
where--
VCLMAX = Speed occurring when lift coefficient is first a maximum.
In addition, if the stalling maneuver is limited by a device that
commands an abrupt nose down pitch (e.g., a stick pusher), VCLMAX
may not be less than the speed existing at the instant the device
operates; and
nZW = Flight patch normal load factor (not greater than 1.0) at
VCLMAX.
6. Section 25.107 is amended by revising paragraphs (b)(1)
introductory text, (b)(2) introductory text, (c)(1) and (c)(2), and by
adding new paragraphs (c)(3) and (g) to read as follows:
Sec. 25.107 Takeoff speeds.
* * * * *
(b) * * *
(1) 1.13 VSR for--
* * * * *
(2) 1.08 VSR for--
* * * * *
(c) * * *
(1) V2MIN;
(2) VR plus the speed increment attained (in accordance with
Sec. 25.111(c)(2)) before reaching a height of 35 feet above the
takeoff surface; and
[[Page 1266]]
(3) A speed that provides the maneuvering capability specified in
Sec. 25.143(g).
* * * * *
(g) VFTO, in terms of calibrated airspeed, must be selected by
the applicant to provide at least the gradient of climb required by
Sec. 25.121(c), but may not be less than--
(1) 1.18 VSR; and
(2) A speed that provides the maneuvering capability specified in
Sec. 25.143(g).
7. Section 25.111 is amended by revising paragraph (a) introductory
text to read as follows:
Sec. 25.111 Takeoff path.
(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 en route
configuration is completed and VFTO is reached, whichever point is
higher. In addition--
* * * * *
8. Section 25.119 is amended by revising the section heading and
paragraph (b) to read as follows:
Sec. 25.119 Landing climb: All-engines-operating.
* * * * *
(b) A climb speed of not more than VREF.
9. Section 25.121 is amended by revising paragraphs (c)
introductory text, (d) introductory text, (d)(2) and (d)(3), and by
adding paragraph (d)(4) to read as follows:
Sec. 25.121 Climb: One-engine-inoperative.
* * * * *
(c) Final takeoff. In the en route configuration at the end of the
takeoff path determined in accordance with Sec. 25.111, the steady
gradient of climb may not be less than 1.2 percent for two-engine
airplanes, 1.5 percent for three-engine airplanes and 1.7 percent for
four-engine airplanes, at VFTO and with--
* * * * *
(d) Approach. In a configuration corresponding to the normal all-
engines-operating procedure in which VSR for this configuration
does not exceed 110 percent of the VSR for the related all-
engines-operating landing configuration, the steady gradient of climb
may not be less than 2.1 percent for two-engine airplanes, 2.4 percent
for three-engine airplanes, and 2.7 percent for four engine airplanes,
with--
(1) * * *
(2) The maximum landing weight;
(3) A climb speed established in connection with normal landing
procedures, but not more than 1.4 VSR; and
(4) Landing gear retracted.
10. Section 25.125 is amended by revising paragraph (a)(2) to read
as follows:
Sec. 25.125 Landing.
(a) * * *
(2) A stabilized approach, with a calibrated airspeed of VREF,
must be maintained down to the 50 foot height. VREF may not be
less than--
(i) 1.23 VSR0,
(ii) VMCL established under Sec. 25.149(f); and
(ii) A speed that provides the maneuvering capability specified in
Sec. 25.143(g).
* * * * *
11. Section 25.143 is amended by adding a new paragraph (g) to read
as follows:
Sec. 25.143 General.
* * * * *
(g) The maneuvering capabilities in a constant speed coordinated
turn at forward center of gravity, as specified in the following table,
must be free of stall warning or other characteristics that might
interfere with normal maneuvering:
----------------------------------------------------------------------------------------------------------------
Maneuvering
bank angle
Configuration Speed in a Thrust/power setting
coordinated
turn
----------------------------------------------------------------------------------------------------------------
Takeoff.................................. V2........................ 30 deg. Asymmetric WAT-limited.1
Takeoff.................................. V2+XX 2................... 40 deg. All-engines-operating
climb.3
En route................................. VFTO...................... 40 deg. Asymmetric WAT-limited.1
Landing.................................. VREF...................... 40 deg. Symmetric for -3 deg. flight
path angle.
----------------------------------------------------------------------------------------------------------------
\1\ A combination of weight, altitude, and temperature (WAT) such that the thrust or power setting produces the
minimum climb gradient specified in Sec. 25.121 for the flight condition.
\2\ Airspeed approved for all-engines-operating initial climb.
\3\ That thrust or power setting which, in the event of failure of the critical engine and without any crew
action to adjust the thrust or power of the remaining engines, would result in the thrust or power specified
for the takeoff condition at V2, or any lesser thrust or power setting that is used for all engines-operating
initial climb procedures.
12. Section 25.145 is amended by revising paragraphs (a)
introductory text, (a)(1), (b)(1), (b)(4), (b)(6), and (c) introductory
text to read as follows:
Sec. 25.145 Longitudinal control.
(a) It must be possible, at any point between the trim speed
prescribed in Sec. 25.103(a)(6) and the stall, to pitch the nose
downward so that the acceleration to this selected trim speed is prompt
with--
(1) The airplane trimmed at the trim speed prescribed in
Sec. 25.103(a)(6);
* * * * *
(b) * * *
(1) With power off, flaps retracted, and the airplane trimmed at
1.3 VSR1, extend the flaps as rapidly as possible while
maintaining the airspeed at approximately 30 percent above the
reference stall speed existing at each instant throughout the maneuver.
* * * * *
(4) With power off, flaps retracted, and the airplane trimmed at
1.3 VSR1, rapidly set go-around power or thrust while maintaining
the same airspeed.
* * * * *
(6) With power off, flaps extended, and the airplane trimmed at 1.3
VSR1, obtain and maintain airspeeds between VSW and either
1.6 VSR1 or VFE, whichever is lower.
(c) It must be possible, without exceptional piloting skill, to
prevent loss of altitude when complete retraction of the high lift
devices from any position is begun during steady, straight, level
flight at 1.08 VSR1 for propeller powered airplanes, or 1.13
VSR1 for turbojet powered airplanes, with--
* * * * *
Sec. 25.147 [Amended]
13. Section 25.147 is amended in paragraphs (a) introductory text,
(a)(2), (c) introductory text, and (d) by revising the expression ``1.4
VS1'' to read ``1.3 VSR1''.
Sec. 25.149 [Amended]
14. Section 25.149 is amended in paragraph (c) introductory text by
revising the expression ``1.2 VS'' to read ``1.13 VSR.''
Sec. 25.161 [Amended]
15. Section 25.161 is amended in paragraphs (b), (c)(1), (c)(2),
(c)(3) and (d) introductory text by revising the expression ``1.4
VS1'' to read ``1.3 VSR1''; and in paragraph (e)(3) by
revising the expression ``0.013 VS02'' to read
``0.013VSR02''.
Sec. 25.175 [Amended]
16. Section 25.175 is amended in paragraphs (a)(2), (b)(1)
introductory text, (b)(2) introductory text, (b)(3)
[[Page 1267]]
introductory text and (c)(4) by revising the expression ``1.4
VS1'' to read ``1.3 VSR1'', in paragraph (b)(2)(ii) by
revising the expression ``VMO+1.4 VS1/2'' to read
``(VMO+1.3 VSR1)/2'', in paragraph (c) introductory text by
revising the expressions ``1.1 VS1'' to read ``VSW'' and
``1.8 VS1'' to read ``1.7 VSR1'', in paragraph (d)
introductory text by revising the expressions ``1.1 VS0'' to read
``VSW'' and ``1.3 VS0'' to read ``1.7 VSR0'', and in
paragraph (d)(5) by revising the expression ``1.4 VSO'' to read
``1.3 VSR0''.
Sec. 25.177 [Amended]
17. Section 25.177 is amended in paragraph (c) by revising the
expression ``1.2 VS1'' to read ``1.13 VSR1''.
Sec. 25.181 [Amended]
18. Section 25.181 is amended in paragraphs (a) introductory text
and (b) by revising the reference ``1.2 VS'' to read ``1.13
VSR''.
19. Section 25.201 is amended by revising paragraphs (a)(2) and
(b)(4) to read as follows:
Sec. 25.201 Stall demonstration.
(a) * * *
(2) The power necessary to maintain level flight at 1.5 VSR1
(where VSR1 corresponds to the reference stall speed with flaps in
the approach position, the landing gear retracted, and the maximum
landing weight).
(b) * * *
(4) The airplane trimmed for straight flight at the speed
prescribed in Sec. 25.103(a)(6).
* * * * *
20. Section 25.207 is amended by revising paragraphs (b) and (c),
and by adding new paragraphs (d), (e), and (f) to read as follows:
Sec. 25.207 Stall warning.
* * * * *
(b) The warning must be furnished either through the inherent
aerodynamic qualities of the airplane or by a device that will give
clearly distinguishable indications under expected conditions of
flight. However, a visual stall warning device that requires the
attention of the crew within the cockpit is not acceptable by itself.
If a warning device is used, it must provide a warning in each of the
airplane configurations prescribed in paragraph (a) of this section at
the speed prescribed in paragraphs (c) and (d) of this section.
(c) When the speed is reduced at rates not exceeding one knot per
second, with engines idling and throttles closed, stall warning must
begin, in each normal configuration, at a speed, VSW, exceeding
the reference stall speed by not less than three knots or three
percent, whichever is greater. For the purposes of this paragraph, the
reference stall speed is as defined in Sec. 25.103, except that
Sec. 25.103(a)(5) does not apply. Stall warning must continue
throughout the demonstration, until the angle of attack is reduced to
approximately that at which stall warning is initiated.
(d) In addition to the requirements of paragraph (c) of this
section, when devices that abruptly push the nose down at a selected
angle of attack (e.g., stick pushers) are installed, the stall warning
must occur at a speed not less than five knots or five percent,
whichever is greater, above the speed at which the device activates.
(e) In slow-down turns up to 1.5g at entry rates up to 3 knots per
second, with the flaps and landing gear in any normal position, the
stall warning margin must be sufficient to allow the pilot to prevent
stalling when recovery is initiated not less than one second after the
onset of stall warning.
(f) Stall warning must also be provided in each abnormal
configuration of the high lift devices that is likely to be used in
flight following system failures (including all configurations covered
by Airplane Flight Manual procedures).
Sec. 25.231 [Amended]
21. Section 25.231 is amended in paragraph (a)(2) by revising the
word ``altitude'' to read ``attitude'' and by revising the expression
``80 percent of VS1'' to read ``75 percent of VSR1''.
Sec. 25.233 [Amended]
22. Section 25.233 is amended in paragraph (a) by revising the
reference ``0.2 VS0'' to read ``0.2 VSR0''.
Sec. 25.237 [Amended]
23. Section 25.237 is amended in paragraphs (a), (b)(1), and (b)(2)
by revising the reference ``0.2 VS0'' to read ``0.2 VSR0''.
24. Action 25.735 is amended by revising paragraphs (f)(2) and (g)
to read as follows:
Sec. 25.735 Brakes.
* * * * *
(f) * * *
(2) Instead of a rational analysis, the kinetic energy absorption
requirements for each main wheel brake assembly may be derived from the
following formula, which must be modified in the case of unequal
braking distribution, which assumes an equal distribution of braking
between main wheels:
KE=0.0443 (WV2/N)
where--
KE=Kinetic energy per wheel (ft.-lb.);
W=Design landing weight (lb.);
V=VREF/1.3
VREF=Airplane steady landing approach speed, in knots, at the
maximum design landing weight and in the landing configuration at sea
level; and
N=Number of main wheels with brakes.
(g) The minimum speed rating of each main wheel-brake assembly
(that is, the initial speed used in the dynamometer tests) may not be
more than the V used in the determination of kinetic energy in
accordance with paragraph (f) of this section, assuming that the test
procedures for wheel-brake assemblies involve a specified rate of
deceleration, and, therefore, for the same amount of kinetic energy,
the rate of energy absorption (the power absorbing ability of the
brake) varies inversely with the initial speed.
Sec. 25.773 [Amended]
25. Section 25.773 is amended in paragraph (b)(1)(i) by revising
the expression ``1.6 VS1'' to read ``1.5 VSR1''.
Sec. 25.1001 [Amended]
26. Section 25.1001 is amended in paragraphs (c)(1) and (c)(3) by
revising the expression ``1.4 VS1'' to read ``1.3 VSR1''.
Sec. 25.1323 [Amended]
27. Section 25.1323 is amended in paragraph (c)(1) by revising the
expression ``1.3 VS1'' to read ``1.23 VSR1'' and in paragraph
(c)(2) by revising the expression ``1.3 VS0'' to read ``1.23
VSR0''.
Sec. 25.1325 [Amended]
28. Section 25.1325 is amended in paragraph (e) by revising the
expressions ``1.3 VS0'' and ``1.8 VS1'' to read ``1.23
VSR0'' and ``1.7 VSR1'', respectively.
Sec. 25.1587 [Amended]
29. Section 25.1587 is amended in paragraph (b)(2) by revising the
expression ``VS'' to read ``VSR''.
PART 36--NOISE STANDARDS: AIRCRAFT TYPE AND AIRWORTHINESS
CERTIFICATION
30. The authority citation for part 36 continues to read as
follows:
Authority: 42 U.S.C. 4321 et seq., 49 U.S.C. 106(g), 40113,
44701-44702, 44704, 44715; sec. 305, Pub. L. 96-193, 94 Stat. 50,
57; E.O. 11514, 35 FR 4247, 3 CFR, 1966-1970 comp., p. 902.
31. Appendix C to part 36, Section C36.9 is amended by revising
paragraph (e)(1) to read as follows:
[[Page 1268]]
Appendix C to Part 36--Noise Levels for Transport Category and Turbojet
Powered Airplanes Under Sec. 36.201
* * * * *
Sec. C36.9 Approach Reference and Test Limitations
* * * * *
(e) * * *
(1) For subsonic airplanes a steady approach speed of VREF +
10 knots must be established and maintained over the approach measuring
point.
* * * * *
PART 97--STANDARD INSTRUMENT APPROACH PROCEDURES
32. The authority citation for part 97 is revised to read as
follows:
Authority: 49 U.S.C. 106(g), 40103, 40106, 40113, 40114, 40120,
44502, 44514, 44701, 44719, 44721-44722.
33. Section 97.3 is amended by revising the first two sentences of
paragraph (b) introductory text to read as follows:
Sec. 97.3 Symbols and terms used in procedures.
* * * * *
(b) Aircraft approach category means a grouping of aircraft based
on a speed of VREF at the maximum certificated landing weight.
VREF and the maximum certificated landing weight are those values
as established for the aircraft by the certification authority of the
country of registry. * * *
* * * * *
Issued in Washington, DC on November 29, 1995.
Thomas E. McSweeny,
Director, Aircraft Certification Service.
[FR Doc. 96-415 Filed 1-17-96; 8:45 am]
BILLING CODE 4910-13-M