[Federal Register Volume 59, Number 78 (Friday, April 22, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-9758]
[[Page Unknown]]
[Federal Register: April 22, 1994]
_______________________________________________________________________
Part III
Department of Transportation
_______________________________________________________________________
Federal Aviation Administration
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14 CFR Parts 1 and 25
Revision of Certain Flight Airworthiness Standards To Harmonize With
European Airworthiness Standards for Transport Category Airplanes;
Proposed Rule and Notice
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Parts 1 and 25
[Docket No. 27705; Notice No. 94-15]
RIN AF 25
Revision of Certain Flight Airworthiness Standards To Harmonize
With European Airworthiness Standards for Transport Category Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking.
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SUMMARY: The Federal Aviation Administration (FAA) proposes to amend
part 25 of the Federal Aviation Regulations (FAR) to harmonize certain
flight requirements with standards proposed for the European Joint
Aviation Requirements 25 (JAR-25). This action responds to a petition
from the Aerospace Industries Association of America, Inc. and the
Association Europeenne des Constructeurs de Materiel Aerospatial. These
changes are intended to benefit the public interest by standardizing
certain requirements, concepts, and procedures contained in the
airworthiness standards of the FAR and the JAR.
DATES: Comments must be received on or before July 21, 1994.
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. 27705, 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. 27705. Comments may be examined in
room 915G weekdays, except Federal holidays, between 8:30 a.m. and 5
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
p.m.
FOR FURTHER INFORMATION CONTACT:
Donald K. 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 is stated:
``Comments to Docket No. 27705.'' 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 (FAA), 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
Part 25 of the Federal Aviation Regulations (FAR) contains the
airworthiness standards for transport category airplanes. Manufacturers
of transport category airplanes must show that each airplane they
produce of a different type design complies with the relevant standards
of part 25. These standards apply to airplanes manufactured within the
U.S. for use by U.S.-registered operators and to airplanes manufactured
in other countries and imported under a bilateral airworthiness
agreement.
In Europe, the Joint Aviation Requirements (JAR) were developed by
the Joint Aviation Authorities (JAA) to provide a common set of
airworthiness standards for use within the European aviation community.
The airworthiness standards for European type certification of
transport category airplanes, JAR-25, are based on part 25 of the FAR.
Airplanes certificated to the JAR-25 standards, including airplanes
manufactured in the U.S. for export to Europe, receive type
certificates that are accepted by the aircraft certification
authorities of 23 European countries.
Although part 25 and JAR-25 are very similar, they are not
identical. Differences between the FAR and the JAR can result in
substantial additional costs when airplanes are type certificated to
both standards. These additional costs, however, do not always bring
about an increase in safety. For example, part 25 and JAR-25 may use
different means to accomplish the same safety intent. In this case, the
manufacturer is usually burdened with meeting both requirements,
although the level of safety is not increased correspondingly.
Recognizing that a common set of standards would not only economically
benefit the aviation industry, but would also maintain the necessary
high level of safety, the FAA and JAA consider harmonization to be a
high priority.
On May 22, 1990, the Aerospace Industries Association of America,
Inc. (AIA) and the Association Europeenne des Constructeurs de Materiel
Aerospatial (AECMA) jointly petitioned the FAA and JAA to harmonize
certain requirements contained in part 25 of the FAR and in JAR-25. In
their petition, a summary of which was published in the July 17, 1990,
edition of the Federal Register (55 FR 137), AIA and AECMA requested
changes to Secs. 25.143(c), 25.143(f), 25.149, and 25.201 to
standardize the requirements, concepts, and procedures for
certification flight testing and to enhance reciprocity between the FAA
and JAA. In addition, AIA and AECMA recommended changes to FAA Advisory
Circular (AC) 25-7, ``Flight Test Guide for Certification of Transport
Category Airplanes,'' to ensure that the harmonized standards would be
interpreted and applied consistently. A copy of that petition is
included in the docket for this rulemaking.
On September 26, 1991, the Aviation Rulemaking Advisory Committee
(ARAC) established the Flight Test Working Group, assigning it the task
of developing either a draft notice of proposed rulemaking (NPRM) or a
denial of the AIA/AECMA petition. If accepted by the ARAC, the draft
NPRM or petition denial would be delivered to the FAA as an advisory
committee recommendation.
The public notice establishing the Flight Test Working Group
appeared in the Federal Register on January 13, 1992 (57 FR 1297). The
Flight Test Working Group was later renamed the Flight Test
Harmonization Working Group and its scope was clarified to include
developing a similar proposal to amend JAR-25, as necessary, to achieve
harmonization.
The rulemaking proposal contained in this notice was developed by
the Flight Test Harmonization Working Group. It was presented to the
FAA by the ARAC as a recommended response to the AIA/AECMA petition.
Rather than proposing a simple acceptance or denial of the petition,
the working group used the petition as a starting point for developing
a rulemaking proposal that would accomplish the goal of harmonizing not
only the sections of part 25 and JAR-25 addressed in the petition, but
also related sections.
The Aviation Rulemaking Advisory Committee
The ARAC was formally established by the FAA on January 22, 1991
(56 FR 2190), to provide advice and recommendations concerning the full
range of the FAA's safety-related rulemaking activity. This advice was
sought to develop better rules in less overall time using fewer FAA
resources than are currently needed. The committee provides the
opportunity for the FAA to obtain firsthand information and insight
from interested parties regarding proposed new rules or revisions of
existing rules.
There are over 60 member organizations on the committee,
representing a wide range of interests within the aviation community.
Meetings of the committee are open to the public, except as authorized
by section 10(d) of the Federal Advisory Committee Act.
The ARAC establishes working groups to develop proposals to
recommend to the FAA for resolving specific issues. Tasks assigned to
working groups are published in the Federal Register. Although working
group meetings are not generally open to the public, all interested
parties are invited to participate as working group members. Working
groups report directly to the ARAC, and the ARAC must concur with a
working group proposal before that proposal can be presented to the FAA
as an advisory committee recommendation.
The activities of the ARAC will not, however, circumvent the public
rulemaking procedures. After an ARAC recommendation is received and
found acceptable by the FAA, the agency proceeds with the normal public
rulemaking procedures. Any ARAC participation in a rulemaking package
will be fully disclosed in the public docket.
Discussion of the Proposals
The FAA proposes amending certain sections of the FAR, as
recommended by the ARAC, to harmonize these sections with JAR-25. The
JAA intend to publish a Notice of Proposed Amendment (NPA), also
developed by the Flight Test Harmonization Working Group, to revise
JAR-25, as necessary, to ensure harmonization in those areas for which
the proposed amendments differ from the current JAR-25. When it is
published, the NPA will be placed in the docket for this rulemaking.
The FAA proposes to: (1) Introduce the term ``go-around power or
thrust setting'' to clarify certain part 25 flight requirements; (2)
revise the maximum control forces permitted for demonstrating
compliance with the controllability and maneuverability requirements;
(3) provide requirements for stick force and stick force gradient in
maneuvering flight; (4) revise and clarify the requirements defining
minimum control speed during approach and landing; (5) clarify the
procedural and airplane configuration requirements for demonstrating
stalls and revise the list of acceptable flight characteristics used to
define the occurrence of stall; and (6) require that stall
characteristics be demonstrated for turning flight stalls at
deceleration rates up to 3 knots per second.
Revisions are also proposed for AC 25-7 to ensure consistent
application of these proposed revised standards. Public comments
concerning the revisions to AC 25-7 are invited by separate notice
published elsewhere in this issue of the Federal Register.
Proposal 1
Certain part 25 flight requirements involving flight conditions
other than takeoff (i.e., Secs. 25.119, 25.121(d), 25.145(b)(3),
25.145(b)(4), 25.145(b)(5), 25.145(c)(1), 25.149(f)(6), and
25.149(g)(7)(ii)) specify using the maximum available takeoff power or
thrust as being representative of the appropriate maximum in-flight
power or thrust. In practice, however, the power or thrust setting used
to obtain the maximum in-flight power or thrust (commonly referred to
as the go-around power or thrust setting) usually differs from the
setting used for takeoff. In the past, the FAA interpreted the words
``maximum available takeoff power or thrust'' to mean the maximum in-
flight power or thrust, with the takeoff power or thrust setting not
always being ``available'' in flight. The FAA proposes changing the
nomenclature to ``go-around power or thrust setting'' for clarity and
to reflect terminology commonly used in the operational environment.
(In the context of this discussion, the term ``go-around'' refers to a
deliberate maneuver to abort a landing attempt prior to touchdown by
applying the maximum available power or thrust, retracting flaps, and
climbing to a safe level-off altitude).
(The go-around power or thrust setting may differ from the takeoff
power or thrust setting, for example, due to the airspeed difference
between the takeoff and go-around flight conditions. In addition,
complying with the powerplant limitations of Sec. 25.1521 may result in
a lower power setting at the higher airspeeds associated with a go-
around. As another example, the controllability requirements of
Secs. 25.145(b)(3), 25.145(b)(4), 25.145(b)(5), 25.149(f), and
25.149(g) may also limit the go-around power or thrust setting to less
than that used for takeoff. Another reason to separate the takeoff and
go-around power (or thrust) nomenclature is that certification practice
has not required, and applicants have not always proposed, changing the
go-around power or thrust setting when a previously approved takeoff
power or thrust is increased.
The FAA proposes to substitute the term ``go-around power or thrust
setting'' for ``maximum available takeoff power or thrust'' in
Secs. 25.119, 25.121(d), 25.145(b)(3), 25.145(b)(4), 25.145(c)(1),
25.149(f)(6), and 25.49(g)(7)(ii). (Note that the requirement of
Sec. 25.145(b)(5) also uses the power specified in Sec. 25.145(b)(4)).
In addition, the FAA proposes to define ``go-around power or thrust
setting'' in part 1 as ``the maximum allowable in-flight power or
thrust setting identified in the performance data.'' With this
revision, the FAA would clarify that the applicable controllability
requirements should be based on the same power or thrust setting used
to determine the approach and landing climb performance contained in
the approved Airplane Flight Manual (AFM).
The proposed terminology refers to a power or thrust ``setting''
rather than a power or thrust to make it clear that existing engine
ratings would be unaffected. The powerplant limitations of Sec. 25.1521
would continue to apply at the go-around power (or thrust) setting.
Existing certification practices would also remain the same, including
the relationship between the power or thrust values used to comply with
the landing and approach climb requirements of Secs. 25.119 and
25.121(d). For example, the thrust value used to comply with
Sec. 25.121(d) may be greater than that used for Sec. 25.119, if the
operating engine(s) do not reach the maximum allowable in-flight thrust
by the end of the eight second time period specified in Sec. 25.119.
Proposal 2
The FAA proposes to revise the table in Sec. 25.143(c) to match the
control force limits currently provided in JAR 25.143(c). This table
prescribes the maximum control forces for the controllability and
maneuverability flight testing required by Secs. 25.143(a) and
25.143(b). For transient application of the pitch and roll control, the
revised table would contain more restrictive maximum control force
limits for those maneuvers in which the pilot might be using one hand
to operate other controls, relative to those maneuvers in which both
hands are normally available for applying pitch and roll control. The
revised table would retain the current control force limits for
transient application of the yaw control, and for sustained application
of the pitch, roll, and yaw controls.
For maneuvers in which only one hand is assumed to be available,
the FAA proposes to reduce the maximum permissible control forces from
75 pounds to 50 pounds for pitch control, and from 60 pounds to 25
pounds for roll control. These lower control forces would be more
consistent with Sec. 25.145(b), which states that a force of 50 pounds
for longitudinal (pitch) control is ``representative of the maximum
temporary force that readily can be applied by one hand.'' In addition
to adding more restrictive control force limits for maneuvers in which
only one hand may be available to apply pitch and roll control, the FAA
proposes to reduce the maximum permissible force for roll control from
60 pounds to 50 pounds for maneuvers in which the pilot normally has
both hands available to operate the control.
The FAA proposes to further revise Sec. 25.143(c) by specifying
that the table of maximum permissible control forces applies only to
conventional wheel type controls. This restriction, also specified in
the current JAR 25.143(c), recognizes that different control force
limits may be necessary when considering sidestick controllers or other
types of control systems.
For clarification, the FAA proposes to replace the terms
``temporary'' and ``prolonged,'' used in Secs. 25.143(c), 25.143(d),
25.143(e), and 25.145(b), with ``transient'' and ``sustained,''
respectively. ``Transient'' forces refer to those control forces
resulting from maintaining the intended flight path during changes to
the airplane configuration, normal transitions from one flight
condition to another, or regaining control after a failure. The pilot
is assumed to take immediate action to reduce or eliminate these forces
by retrimming or by changing the airplane configuration or flight
condition. ``Sustained forces,'' on the other hand, refer to those
control forces resulting from normal or failure conditions that cannot
readily be trimmed out or eliminated. The FAA is proposing to add these
definitions of ``transient'' and ``sustained'' forces to AC 25-7.
In addition, the FAA proposes several minor editorial changes for
Secs. 25.143(c) through 25.143(e) to improve readability and correct
grammatical errors. For example, the words ``immediately preceding''
are proposed to replace ``next preceding'' in Sec. 25.143(d). These
editorial changes are intended to clarify the existing interpretation
of the affected sections.
Proposal 3
The FAA proposes to add the JAR 25.143(f) requirements regarding
control force characteristics during maneuvering flight to part 25 as a
new Sec. 25.143(f). By adding these requirements, the FAA would ensure
that the force to move the control column, or ``stick,'' must not be so
great as to make excessive demands on the pilot's strength when
maneuvering the airplane, and must not be so low that the airplane can
easily be overstressed inadvertently.
These harmonized requirements would apply up to the speed VFC/
MFC (the maximum speed for stability characteristics) rather than
the speed VMO/MMO (the maximum operating limit speed)
specified by the current JAR 25.143(f). Requiring these maneuvering
requirements to be met up to VFC/MFC is consistent with other
part 25 stability requirements. Section 25.253, which defines VFC/
MFC, would be revised to reference the use of this speed in the
proposed Sec. 25.143(f). An acceptable means of compliance with
Sec. 25.143(f), including detailed interpretations of the stick force
characteristics that meet these requirements, would be added to AC 25-
7.
Proposal 4
Section 25.149(f) requires that the minimum control speed be
determined assuming the critical engine suddenly fails during (or just
prior to) go-around from an all-engines-operating approach. For
airplanes with three or more engines, Sec. 25.149(g) requires the
minimum control speed to be determined for a one-engine-inoperative
landing approach in which a second critical engine suddenly fails. The
FAA proposes to revise Secs. 25.149(f) through 25.149(h) to clarify and
revise the criteria for establishing these minimum control speeds,
VMCL and VMCL-2, respectively, for use during approach and
landing.
The FAA proposes to clarify that VMCL and VMCL-2 apply
not only to the airplane's approach configuration(s), as prescribed in
the current standards, but also to the landing configuration(s). The
FAA recognizes that configuration changes occur during approach and
landing (e.g., flap setting and landing gear position) and considers
that the minimum control speeds provided in the AFM should ensure
airplane controllability, following a sudden engine failure, throughout
the approach and landing.
Applicants would have the option of determining VMCL and
VMCL-2 either for the most critical of the approach and landing
configurations (i.e., the configuration resulting in the highest
minimum control speed), or for each configuration used for approach or
for landing. By determining the minimum control speeds in the most
critical configuration, applicants would not be required to conduct any
additional testing to that already required by the current standards.
Only if these resulting speeds proved too constraining for other
configurations would the FAA expect applicants to exercise the option
of testing multiple configurations.
The FAA also proposes to add provisions to state the position of
the propeller, for propeller airplanes, when establishing these minimum
control speeds. For the critical engine that is suddenly made
inoperative, the propeller position must reflect the most critical mode
of powerplant failure with respect to controllability, as required by
Sec. 25.149(a). Also, since credit cannot be given for pilot action to
feather the propeller during this high flightcrew workload phase of
flight, the FAA proposes that VMCL and VMCL-2 be determined
with the propeller position of the most critical engine in the position
it automatically achieves. For VMCL-2, the engine that is already
inoperative before beginning the approach may be feathered, since the
pilot is expected to ensure the propeller is feathered before
initiating the approach.
To assure that airplanes have adequate lateral control capability
at VMCL and VMCL-2, the FAA proposes to require the airplane
to be capable of rolling, from an initial condition of steady straight
flight, through an angle of 20 degrees in not more than 5 seconds, in
the direction necessary to start a turn away from the inoperative
engine. This proposed addition to Sec. 25.149 is contained in the
current JAR 25.149.
The FAA is proposing guidance material for AC 25-7 to enable
applicants to additionally determine the appropriate minimum control
speeds for an approach and landing in which one engine, and, for
airplanes with three or more engines, two engines, are already
inoperative prior to beginning the approach. These speeds, VMCL(1
out) and VMCL-2(2 out), would be less restrictive than VMCL
and VMCL-2 because the pilot is assumed to have trimmed the
airplane for the approach with an inoperative engine (for VMCL(1
out)) or two inoperative engines (for VMCL-2(2 out)). Also, the
approach and landing procedures under these circumstances may use
different approach and landing flaps than for the situations defining
VMCL or VMCL-2. These additional speeds can be used as
guidance in determining the recommended procedures and speeds for a
one-engine-inoperative, or, in the case of an airplane with three or
more engines, a two-engine-inoperative approach and landing.
The FAA proposes to revise Sec. 25.125 to require the approach
speed used for determining the landing distance to be equal to or
greater than VMCL, the minimum control speed for approach and
landing with all-engines-operating. This provision would ensure that
the speeds used for normal landing approaches with all-engines-
operating would provide satisfactory controllability in the event of a
sudden engine failure during, or just prior to, a go-around.
Proposal 5
The FAA proposes to revise the stall demonstration requirements of
Sec. 25.201 to clarify the airplane configurations and procedures used
in flight tests to demonstrate stall speeds and stall handling
characteristics. The list of acceptable flight characteristics used to
define the occurrence of stall would also be revised. To be consistent
with current practice, Sec. 25.201(b)(1) would require that stall
demonstrations also be conducted with deceleration devices (e.g., speed
brakes) deployed. Additionally, the FAA proposes clarifying the intent
of Sec. 25.201(b) to cover normal, rather than failure, conditions by
requiring that stalls need only be demonstrated for the approved
configurations.
Section 25.201(c) would be revised to more accurately describe the
procedures used for demonstrating stall handling characteristics. The
cross-reference to Sec. 25.103(b), currently contained in
Sec. 25.201(c)(1), would be moved to a new Sec. 25.201(b)(4) for
editorial clarity and harmony with the JAR-25 format. Reference to the
pitch control reaching the aft stop, which would be interpreted as one
of the indications that the airplane has stalled, would be moved from
Sec. 25.201(c)(1) to Sec. 25.201(d)(3).
The list of acceptable flight characteristics that define the
occurrence of a stall, used during the flight tests demonstrating
compliance with the stall requirements, is provided in Sec. 25.201(d).
The FAA proposes to revise this list to conform with current practices.
Section 25.201(d)(1)(ii) would be removed to clarify that a rolling
motion, occurring by itself, is not considered an acceptable flight
characteristic for defining the occurrence of a stall. The proposed
Sec. 25.201(d)(2) would replace the criteria of Secs. 25.201(d)(1)(iii)
and 25.201(d)(2) because only deterrent buffeting (i.e., a distinctive
shaking of the airplane that is a strong and effective deterrent to
further speed reduction) is considered to comply with those criteria.
Finally, the proposed Sec. 25.201(d)(3) would define as a stall a
condition in which the airplane does not continue to pitch up after the
pitch control has been pulled back as far as it will go and held there
for a short period of time. Guidance material would be added to AC 25-7
to define the length of time that the control stick must be held in
this full aft position when using Sec. 25.201(d)(3) to define a stall.
Proposal 6
Section 25.201 currently requires stalls to be demonstrated at
airspeed deceleration rates (i.e., entry rates) not exceeding one knot
per second. JAR 25.201 currently requires, in addition, that turning
flight stalls must also be demonstrated at accelerated rates of entry
into the stall (i.e., dynamic stalls). According to the JAA, the
intended procedure for demonstrating dynamic stalls begins with a 1
knot per second deceleration from the trim speed (similar to normal
stalls). Then, approximately halfway between the trim speed and the
stall warning speed, the flight test pilot applies the elevator control
to achieve an increase in the rate of change of angle-of-attack. The
final angle-of-attack rate and the control input to achieve it should
be appropriate to the type of airplane and its particular control
characteristics.
The AIA/AECMA petition detailed various difficulties with
interpretation of the JAR-25 requirement, noted that the requirement is
not contained in the FAR, and proposed that dynamic stalls be removed
from JAR-25. Some of the concerns with the JAR-25 dynamic stall
requirement include: (1) A significant number of flight test
demonstrations for compliance used inappropriate piloting techniques
considering the capabilities of transport category airplanes; (2) the
stated test procedures depend, to a large extent, on pilot
interpretation, resulting in test demonstrations that could vary
significantly for different test pilots; (3) the safety objective of
the requirement is not well understood within the aviation community;
and (4) the flight test procedures that are provided are inconsistent
with the flight characteristics being evaluated. As a result,
applicants are unable to ensure that their designs will comply with the
JAR-25 dynamic stall requirement prior to the certification flight
test.
In practice, FAA certification testing has typically included stall
demonstrations at entry rates higher than 1 knot per second. For
airplanes with certain special features, such as systems designed to
prevent a stall or that are needed to provide an acceptable stall
indication, higher entry rates are demonstrated to show that the system
will continue to safely perform its intended function under such
conditions. These higher entry rate stalls are different, however, from
the JAR-25 dynamic stalls.
Rather than simply deleting the dynamic stall requirement from JAR-
25, or adding this requirement to part 25 of the FAR, the ARAC
recommended harmonizing the two standards by requiring turning flight
stalls be demonstrated at steady airspeed deceleration rates up to 3
knots per second. The FAA agrees with this recommendation and proposes
to add the requirement for a higher entry rate stall demonstration to
part 25 as Sec. 25.201(c)(2). The current Sec. 25.201(c)(2) would be
redesignated Sec. 25.201(c)(3). The JAA is proposing to replace the
JAR-25 dynamic stall requirement with the ARAC recommendation.
The proposed higher entry rate stall demonstration is a controlled
and repeatable maneuver that meets the objective of evaluating stall
characteristics over a range of entry conditions that might reasonably
be encountered by transport category airplanes in operational service.
Some degradation in characteristics would be accepted at the higher
entry rates, as long as it does not present a major threat to recovery
from the point at which the pilot has recognized the stall. Guidance
material is being proposed for AC 25-7 to point out that the specified
deceleration rate, and associated rate of increase in angle of attack,
should be established from the trim speed specified in
Sec. 25.103(b)(1) and maintained up to the point at which the airplane
stalls.
The FAA proposes to revise Sec. 25.203(c) to specify a bank angle
that must not be exceeded during the recovery from the turning flight
stall demonstrations. Currently, Sec. 25.203(c) provides only a
qualitative statement that a prompt recovery must be easily attainable
using normal piloting skill. By specifying a maximum bank angle limit,
the FAA proposes to augment this qualitative requirement with a
quantitative one.
For deceleration rates up to 1 knot per second, the maximum bank
angle would be approximately 60 degrees in the original direction of
the turn, or 30 degrees in the opposite direction. These bank angle
limits are currently contained in JAR-25 guidance material, and have
been used informally during FAA certification programs as well. For
deceleration rates higher than 1 knot per second, the FAA proposes to
allow a greater maximum bank angle--approximately 90 degrees in the
original direction of the turn, or 60 degrees in the opposite
direction. These are the same acceptance criteria currently used by the
JAA to evaluate dynamic stall demonstrations.
In addition to the amendments to part 25 proposed in this notice,
revisions to AC 25-7 are being proposed to ensure that the harmonized
standards would be interpreted and applied consistently. AC 25-7
provides guidelines that the FAA has found acceptable regarding flight
testing transport category airplanes to demonstrate compliance with the
applicable airworthiness requirements. Public comments concerning the
proposed revisions to AC 25-7 are invited by separate notice published
elsewhere in this issue of the Federal Register.
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 the 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 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 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.
Cost Benefit Analysis
Three of the proposed 48 revisions to the flight test airworthiness
standards of part 25 would require additional flight testing and
engineering analysis, resulting in compliance costs of $18,500 per type
certification. When amortized over a representative production run of
500 airplanes, this total cost would result in a negligible incremental
cost of $37 per airplane. The FAA solicits comments concerning the
incremental flight test certification costs attributable to the
proposed rule.
The primary benefits of the proposed rule would be harmonization of
flight test airworthiness standards with the European Joint Aviation
Requirements and clarification of existing standards. The resulting
increased uniformity of flight test standards would simplify
airworthiness approval for import and export purposes and would avoid
some of the costs that can result when manufacturers seek type
certification under both sets of standards. While not readily
quantifiable, the potential cost avoidance would exceed the relatively
minor incremental costs of the proposed rule.
The proposed rule would provide additional benefits by updating
certain airworthiness standards. These updated standards would adopt
terminology commonly used in airplane operations as well as better
reflect current flight test practices.
Regulatory Flexibility Determination
The Regulatory Flexibility Act of 1980 (RFA) was enacted by
Congress to ensure that small entities are not unnecessarily or
disproportionately burdened by Federal regulations. The RFA requires a
Regulatory Flexibility Analysis if a proposed rule would have a
significant economic impact, either detrimental or beneficial, on a
substantial number of small entities. Based on FAA Order 2100.14A,
Regulatory Flexibility Criteria and Guidance, the FAA has determined
that the proposed amendments would not have a significant economic
impact on a substantial number of small entities.
Trade Impact Assessment
The proposed rule would not constitute a barrier to international
trade, including the export of American airplanes to foreign countries,
and the import of foreign airplanes into the United States. Instead,
the proposed flight testing standards have been harmonized with those
of foreign 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 standardize specific flight
requirements of part 25 of the FAR 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.
The Proposed Amendments
Accordingly, the Federal Aviation Administration (FAA) proposed to
amend 14 CFR parts 1 and 25 of the Federal Aviation Regulations (FAR)
as follows:
PART 1--DEFINITIONS AND ABBREVIATIONS
1. The authority citation for part 1 continues to read as follows:
Authority: 49 U.S.C. app. 1347, 1348, 1354(a), 1357(d)(2), 1372,
1421 through 1430, 1432, 1442, 1443, 1472, 1510, 1522, 1652(e),
1655(c), 1657(f), and 49 U.S.C. 106(g).
2. Section 1.1 is amended by adding a new definition to read as
follows:
Sec. 1.1 General definitions.
* * * * *
``Go-around power or thrust setting'' means the maximum allowable
in-flight power or thrust setting identified in the performance data.
* * * * *
PART 25--AIRWORTHINESS STANDARDS--TRANSPORT CATEGORY AIRPLANES
3. The authority citation for part 25 continues to read as follows:
Authority: 49 U.S.C. app. 1344, 1354(a), 1355, 1421, 1423, 1424,
1425, 1428, 1429, 1430; 49 U.S.C. 106(g); and 49 CFR 1.47(a).
4. Section 25.119 is amended by revising paragraph (a) to read as
follows:
Sec. 25.119 Landing climb: All-engines-operating.
* * * * *
(a) The engines at the power or thrust that is available eight
seconds after initiation of movement of the power or thrust controls
from minimum flight idle to the go-around power or thrust setting; and
* * * * *
5. Section 25.121 is amended by revising paragraph (d)(1) to read
as follows:
Sec. 25.121 Climb: One-engine-inoperative.
* * * * *
(d) * * *
(1) The critical engine inoperative, the remaining engines at the
go-around power or thrust setting;
* * * * *
6. 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 not less
than 1.3 VS or VMCL, must be maintained down to the 50 foot
height.
* * * * *
7. Section 25.143 is amended by revising paragraphs (c), (d), and
(e) and adding a new paragraph (f) to read as follows:
Sec. 25.143 General.
* * * * *
(c) The following table prescribes, for conventional wheel type
controls, the maximum control forces permitted during the testing
required by paragraphs (a) and (b) of this section:
------------------------------------------------------------------------
Force, in pounds, applied to the control wheel
or rudder pedals Pitch Roll Yaw
------------------------------------------------------------------------
For transient application for pitch and roll
control--two hands available for control....... 75 50
For transient application for pitch and roll
control--one hand available for control........ 50 25
For transient application for yaw control....... ....... ...... 150
For sustained application....................... 10 5 20
------------------------------------------------------------------------
(d) Approved operating procedures or conventional operating
practices must be followed when demonstrating compliance with the
control force limitations for transient application that are prescribed
in paragraph (c) of this section. The airplane must be in trim, or as
near to being in trim as practical, in the immediately preceding steady
flight condition. For the takeoff condition, the airplane must be
trimmed according to the approved operating procedures.
(e) When demonstrating compliance with the control force
limitations for sustained application that are prescribed in paragraph
(c) of this section, the airplane must be in trim, or as near to being
in trim as practical.
(f) When maneuvering at a constant airspeed or Mach number (up to
VFC/MFC), the stick forces and the gradient of the stick
force versus maneuvering load factor must lie within satisfactory
limits. The stick forces must not be so great as to make excessive
demands on the pilot's strength when maneuvering the airplane, and must
not be so low that the airplane can easily be overstressed
inadvertently. Changes of gradient that occur with changes of load
factor must not cause undue difficulty in maintaining control of the
airplane, and local gradients must not be so low as to result in a
danger of overcontrolling.
8. Section 25.145 is amended by revising the introductory text of
paragraph (b), and paragraphs (b)(3), (b)(4), and (c)(1) to read as
follows:
Sec. 25.145 Longitudinal control.
* * * * *
(b) With the landing gear extended, no change in trim control, or
exertion of more than 50 pounds control force (representative of the
maximum transient force that can be applied readily by one hand) may be
required for the following maneuvers:
* * * * *
(3) Repeat paragraph (b)(2) except at the go-around power or thrust
setting.
(4) With power off, flaps retracted, and the airplane trimmed at
1.4 VS2, rapidly set go-around power or thrust while maintaining
the same airspeed.
(4) WITH POWER OFF, FLAPS RETRACTED, AND THE AIRPLANE TRIMMED AT
1.4 VS1, RAPIDLY SET GO-AROUND POWER OR THRUST WHILE
MAINTAINING THE SAME AIRSPEED.
* * * * *
(c) * * *
(1) Simultaneous movement of the power or thrust controls to the
go-around power or thrust setting;
* * * * *
9. Section 25.149 is amended by revising paragraphs (f), (g) and
(h) to read as follows:
Sec. 25.149 Minimum Control Speed.
* * * * *
(f) VMCL, the minimum control speed during approach and
landing with all engines operating, is the calibrated airspeed at
which, when the critical engine is suddenly made inoperative, it is
possible to maintain control of the airplane with that engine still
inoperative, and maintain straight flight with an angle of bank of not
more than 5 degrees. VMCL must be established with--
(1) The airplane in the most critical configuration (or, at the
option of the applicant, each configuration) for approach and landing
with all engines operating;
(2) The most unfavorable center of gravity;
(3) The airplane trimmed for approach with all engines operating;
(4) The most unfavorable weight, or, at the option of the
applicant, as a function of weight;
(5) The propeller of the inoperative engine, if applicable, in the
position it automatically achieves; and
(6) Go-around power or thrust setting on the operating engine(s).
(g) For airplanes with three or more engines, VMCL-2, the
minimum control speed during approach and landing with one critical
engine inoperative, is the calibrated airspeed at which, when a second
critical engine is suddenly made inoperative, it is possible to
maintain control of the airplane with both engines still inoperative,
and maintain straight flight with an angle of bank of not more than 5
degrees. VMCL-2 must be established with--
(1) The airplane in the most critical configuration (or, at the
option of the applicant, each configuration) for approach and landing
with one critical engine inoperative;
(2) The most unfavorable center of gravity;
(3) The airplane trimmed for approach with one critical engine
inoperative;
(4) The most unfavorable weight, or, at the option of the
applicant, as a function of weight;
(5) If applicable, the propeller of the more critical engine in the
position it automatically achieves and the propeller of the other
inoperative engine feathered;
(6) The power or thrust on the operating engine(s) necessary to
maintain an approach path angle of 3 degrees when one critical engine
is inoperative; and
(7) The power or thrust on the operating engine(s) rapidly changed,
immediately after the second critical engine is made inoperative, from
the power or thrust prescribed in paragraph (g)(6) of this section to--
(i) Minimum power or thrust; and
(ii) Go-around power or thrust setting.
(h) In demonstrations of VMCL and VMCL-2--
(1) The rudder force may not exceed 150 pounds;
(2) The airplane may not exhibit hazardous flight characteristics
or require exceptional piloting skill, alertness, or strength;
(3) Lateral control must be sufficient to roll the airplane, from
an initial condition of steady straight flight, through an angle of 20
degrees in the direction necessary to initiate a turn away from the
inoperative engine(s), in not more than 5 seconds; and
(4) For propeller airplanes, hazardous flight characteristics must
not be exhibited due to any propeller position achieved when the engine
fails or during any likely subsequent movements of the engine or
propeller controls.
10. Section 25.201 is amended by revising paragraphs (b), (c), and
(d) to read as follows:
Sec. 25.201 Stall demonstration.
* * * * *
(b) In each condition required by paragraph (a) of this section, it
must be possible to meet the applicable requirements of Sec. 25.203
with--
(1) Flaps, landing gear, and deceleration devices in any likely
combination of positions approved for operation;
(2) Representative weights within the range for which certification
is requested;
(3) The most adverse center of gravity for recovery; and
(4) The airplane trimmed for straight flight at the speed
prescribed in Sec. 25.103(b)(1).
(c) The following procedures must be used to show compliance with
Sec. 25.203:
(1) Starting at a speed sufficiently above the stalling speed to
ensure that a steady rate of speed reduction can be established, apply
the longitudinal control so that the speed reduction does not exceed
one knot per second until the airplane is stalled.
(2) In addition, for turning flight stalls, apply the longitudinal
control to achieve airspeed deceleration rates up to 3 knots per
second.
(3) As soon as the airplane is stalled, recover by normal recovery
techniques.
(d) The airplane is considered stalled when the behavior of the
airplane gives the pilot a clear and distinctive indication of an
acceptable nature that the airplane is stalled. Acceptable indications
of a stall, occurring either individually or in combination, are--
(1) A nose-down pitch that cannot be readily arrested, which may be
accompanied by a rolling motion that is not immediately controllable
(provided that the rolling motion complies with Sec. 25.203 (b) or (c)
as appropriate);
(2) Buffeting, of a magnitude and severity that is a strong and
effective deterrent to further speed reduction; or
(3) The pitch control reaches the aft stop and no further increase
in pitch attitude occurs when the control is held full aft for a short
time before recovery is initiated.
11. Section 25.203 is amended by revising paragraph (c) to read as
follows:
Sec. 25.203 Stall characteristics.
* * * * *
(c) For turning flight stalls, the action of the airplane after the
stall may not be so violent or extreme as to make it difficult, with
normal piloting skill, to effect a prompt recovery and to regain
control of the airplane. The maximum bank angle that occurs during the
recovery may not exceed--
(1) Approximately 60 degrees in the original direction of the turn,
or 30 degrees in the opposite direction, for deceleration rates up to 1
knot per second; and
(2) Approximately 90 degrees in the original direction of the turn,
or 60 degrees in the opposite direction, for deceleration rates in
excess of 1 knot per second.
12. Section 25.253 is amended by revising paragraph (b) to read as
follows:
Sec. 25.253 High-speed characteristics.
* * * * *
(b) Maximum speed for stability characteristics, VFC/MCF.
VFC/MFC is the maximum speed at which the requirements of
Secs. 25.143(f), 25.147(e), 25.175(b)(1), 25.177, and 25.181 must be
met with 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.
Issued in Washington, DC, on April 11, 1994.
Thomas E. McSweeny,
Director, Aircraft Certification Service.
[FR Doc. 94-9758 Filed 4-21-94; 8:45 am]
BILLING CODE 4910-13-M
