[Federal Register Volume 77, Number 202 (Thursday, October 18, 2012)]
[Rules and Regulations]
[Pages 64029-64031]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-25605]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA-2012-1119; Special Conditions No. 25-470-SC]
Special Conditions: Airbus Model A318, A319, A320, and A321
Series Airplanes; Design Dive Speed
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions; request for comments.
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SUMMARY: These special conditions are issued for the Airbus Model A318,
A319, and A320 series airplanes with modification 160500 and Model A321
series airplanes with modification 160023 (Sharklet). These airplanes
will have novel or unusual design features when compared to the state
of technology envisioned in the airworthiness standards for transport
category airplanes. These design features include a high-speed
protection system. The applicable airworthiness regulations do not
contain adequate or appropriate safety standards for this design
feature. These special conditions contain the additional safety
standards that the Administrator considers necessary to establish a
level of safety equivalent to that established by the existing
airworthiness standards.
DATES: The effective date of these special conditions is October 11,
2012. We must receive your comments by December 3, 2012.
ADDRESSES: Send comments identified by docket number FAA-2012-1119
using any of the following methods:
Federal eRegulations Portal: Go to http://www.regulations.gov/ and follow the online instructions for sending
your comments electronically.
Mail: Send comments to Docket Operations, M-30, U.S.
Department of Transportation (DOT), 1200 New Jersey Avenue SE., Room
W12-140, West Building Ground Floor, Washington, DC, 20590-0001.
Hand Delivery or Courier: Take comments to Docket
Operations in Room W12-140 of the West Building Ground Floor at 1200
New Jersey Avenue SE., Washington, DC, between 8 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays.
Fax: Fax comments to Docket Operations at 202-493-2251.
Privacy: The FAA will post all comments it receives, without
change, to http:[sol][sol]www.regulations.gov/, including any personal
information the commenter provides. Using the search function of the
docket Web site, anyone can find and read the electronic form of all
comments received into any FAA docket, including the name of the
individual sending the comment (or signing the comment for an
association, business, labor union, etc.). DOT's complete Privacy Act
Statement can be found in the Federal Register published on April 11,
2000 (65 FR 19477-19478), as well as at http:[sol][sol]
DocketsInfo.dot.gov/.
Docket: Background documents or comments received may be read at
http:[sol][sol]www.regulations.gov/ at any time. Follow the online
instructions for accessing the docket or go to the Docket Operations in
Room W12-140 of the West Building Ground Floor at 1200 New Jersey
Avenue SE., Washington, DC, between 9 a.m. and 5 p.m., Monday through
Friday, except Federal holidays.
FOR FURTHER INFORMATION CONTACT: Todd Martin, FAA, Airframe/Cabin
Safety Branch, ANM-115, Transport Airplane Directorate, Aircraft
Certification Service, 1601 Lind Avenue SW., Renton, Washington 98057-
3356; telephone 425-227-1178; facsimile 425-227-1232.
SUPPLEMENTARY INFORMATION: The FAA has determined that notice of, and
opportunity for prior public comment on, these special conditions are
impracticable because these procedures would significantly delay
issuance of the design approval and thus delivery of the affected
aircraft. In addition, the substance of these special conditions has
been subject to the public comment process in several prior instances
with no substantive comments received. The FAA therefore finds that
good cause exists for making these special conditions effective upon
issuance.
Comments Invited
We invite interested people to take part in this rulemaking by
sending written comments, data, or views. The most helpful comments
reference a specific portion of the special conditions, explain the
reason for any recommended change, and include supporting data.
We will consider all comments we receive by the closing date for
comments. We may change these special conditions based on the comments
we receive.
Background
On April 8, 2010, Airbus applied for a change to Type Certificate
No. A28NM to include modification 160500 on Airbus Model A318, A319,
and A320 series airplanes and modification 160023 on Model A321 series
airplanes for the installation of a ``Sharklet,'' a large wingtip
device. The Model A318, A319, A320, and A321 series airplanes are short
to medium-range, twin turbofan, transport category airplanes with a
maximum seating capacity of 136 to 220 passengers, a maximum takeoff
weight of 130,071 to 205,027 pounds, and a maximum operating altitude
of 39,800 feet.
FAA issued special conditions 25-ANM-23, effective December 15,
1988, originally applicable to Airbus Model A320 series airplanes and
later to the Model A318, A319, and A321 series airplanes. Those special
conditions included revised requirements for dive speed based on
incorporation of high-speed protection in the fight control laws. The
FAA has determined that new special conditions are needed for the
Airbus Model A318, A319, and A320 series airplanes with modification
160500 and Model A321 series airplanes with modification 160023
(Sharklet) and later derivatives because the existing special
conditions have evolved over the years and need to be updated for this
derivative program.
[[Page 64030]]
Type Certification Basis
Under the provisions of Title 14, Code of Federal Regulation (14
CFR) 21.101, Airbus must show that the Model A318, A319, A320, and A321
series airplanes, as changed, continue to meet the applicable
provisions of the regulations incorporated by reference in Type
Certificate No. A28NM or the applicable regulations in effect on the
date of application for the change. The regulations incorporated by
reference in the type certificate are commonly referred to as the
``original type certification basis.'' The regulations incorporated by
reference in Type Certificate No. A28NM are 14 CFR part 25, as amended
by Amendments 25-1 through 25-56, and special conditions 25-ANM-23. In
addition, the certification basis includes certain special conditions,
exemptions, or later amended sections of the applicable part that are
not relevant to these special conditions.
If the Administrator finds that the applicable airworthiness
regulations (i.e., 14 CFR part 25) do not contain adequate or
appropriate safety standards for the Model A318, A319, A320, and A321
series airplanes because of a novel or unusual design feature, special
conditions are prescribed under the provisions of Sec. 21.16.
Special conditions are initially applicable to the model for which
they are issued. Should the type certificate for that model be amended
later to include any other model that incorporates the same novel or
unusual design feature, or should any other model already included on
the same type certificate be modified to incorporate the same novel or
unusual design feature, the special conditions would also apply to the
other model.
In addition to the applicable airworthiness regulations and special
conditions, the Model A318, A319, A320, and A321 series airplanes must
comply with the fuel vent and exhaust emission requirements of 14 CFR
part 34 and the noise certification requirements of 14 CFR part 36.
The FAA issues special conditions, as defined in 14 CFR 11.19, in
accordance with Sec. 11.38, and they become part of the type-
certification basis under Sec. 21.101.
Novel or Unusual Design Features
The Airbus Model A318, A319, and A320 series airplanes with
modification 160500 and Model A321 series airplanes with modification
160023 (Sharklet) will incorporate the following novel or unusual
design feature: A high-speed protection system that limits nose-down
pilot authority at speeds above VC/MC. This
system prevents the airplane from performing the maneuver required
under Sec. 25.335(b)(1).
Discussion
Section 25.335(b)(1) is an analytical envelope condition that was
originally adopted in part 4b of the Civil Air Regulations in order to
provide an acceptable speed margin between design cruise speed and
design dive speed. Flutter clearance design speeds and airframe design
loads are impacted by the design dive speed. While the initial
condition for the upset specified in the rule is 1g level flight,
protection is afforded for other inadvertent overspeed conditions as
well. Section 25.335(b)(1) is intended as a conservative enveloping
condition for potential overspeed conditions, including non-symmetric
ones. To establish that potential overspeed conditions are enveloped,
the applicant should demonstrate that any reduced speed margin, based
on the high-speed protection system in the Model A318, A319, and A320
series airplanes with modification 160500 and Model A321 series
airplanes with modification 160023 (Sharklet), will not be exceeded in
inadvertent, or gust-induced, upsets resulting in initiation of the
dive from non-symmetric attitudes; or that the airplane is protected by
the flight control laws from getting into non-symmetric upset
conditions. The applicant should conduct a demonstration that includes
a comprehensive set of conditions, as described below.
These special conditions are proposed in lieu of Sec.
25.335(b)(1). Section 25.335(b)(2), which also addresses the design
dive speed, is applied separately. Advisory Circular (AC) 25.335-1A
provides an acceptable means of compliance to Sec. 25.335(b)(2)).
Special conditions are necessary to address the high-speed
protection system on the Model A318, A319, and A320 series airplanes
with modification 160500 and Model A321 series airplanes with
modification 160023 (Sharklet). The proposed special conditions
identify various symmetric and non-symmetric maneuvers that will ensure
that an appropriate design dive speed, VD/MD, is
established.
These special conditions contain the additional safety standards
that the Administrator considers necessary to establish a level of
safety equivalent to that established by the existing airworthiness
standards.
Applicability
As discussed above, these special conditions are applicable to the
Airbus Model A318, A319, A320 series airplanes with modification 160500
and Model A321 series airplanes with modification 160023 (Sharklet).
Should Airbus apply at a later date for a change to the type
certificate to include another model incorporating the same novel or
unusual design feature, the special conditions would apply to that
model as well.
Conclusion
This action affects only certain novel or unusual design features
on the model series of airplanes listed above. It is not a rule of
general applicability.
The substance of these special conditions has been subjected to the
notice and comment period in several prior instances and has been
derived without substantive change from those previously issued. It is
unlikely that prior public comment would result in a significant change
from the substance contained herein. Therefore, because a delay would
significantly affect the certification of the airplane, which is
imminent, the FAA has determined that prior public notice and comment
are unnecessary and impracticable, and good cause exists for adopting
these special conditions upon issuance. The FAA is requesting comments
to allow interested persons to submit views that may not have been
submitted in response to the prior opportunities for comment described
above.
List of Subjects in 14 CFR Part 25
Aircraft, Aviation safety, Reporting and recordkeeping
requirements.
The authority citation for these special conditions is as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704.
The Special Conditions
Accordingly, pursuant to the authority delegated to me by the
Administrator, the following special conditions are issued as part of
the type certification basis for Airbus Model A318, A319, and A320
series airplanes with modification 160500 and Model A321 with
modification 160023 (Sharklet) series airplanes.
1. Design Dive Speed. In lieu of compliance with Sec.
25.335(b)(1), if the flight control system includes functions that act
automatically to initiate recovery before the end of the 20 second
period specified in Sec. 25.335(b)(1), VD/MD
must be determined from the greater of the speeds resulting from
conditions (a) and (b) below. The speed increase occurring in these
maneuvers may be calculated if reliable or conservative aerodynamic
data are used.
[[Page 64031]]
(a) From an initial condition of stabilized flight at
VC/MC, the airplane is upset so as to take up a
new flight path 7.5 degrees below the initial path. Control
application, up to full authority, is made to try and maintain this new
flight path. Twenty seconds after initiating the upset, manual recovery
is made at a load factor of 1.5 g (0.5 acceleration increment), or such
greater load factor that is automatically applied by the system with
the pilot's pitch control neutral. Power, as specified in Sec.
25.175(b)(1)(iv), is assumed until recovery is initiated, at which time
power reduction and the use of pilot controlled drag devices may be
used.
(b) From a speed below VC/MC, with power to
maintain stabilized level flight at this speed, the airplane is upset
so as to accelerate through VC/MC at a flight
path 15 degrees below the initial path (or at the steepest nose-down
attitude that the system will permit with full control authority if
less than 15 degrees). The pilot's controls may be in the neutral
position after reaching VC/MC and before recovery
is initiated. Recovery may be initiated three seconds after operation
of high-speed warning system by application of a load of 1.5g (0.5
acceleration increment), or such greater load factor that is
automatically applied by the system with the pilot's pitch control
neutral. Power may be reduced simultaneously. All other means of
decelerating the airplane, the use of which is authorized up to the
highest speed reached in the maneuver, may be used. The interval
between successive pilot actions must not be less than one second.
2. The applicant must also demonstrate that the speed margin,
established as above, will not be exceeded in inadvertent or gust-
induced upsets resulting in initiation of the dive from non-symmetric
attitudes, unless the airplane is protected by the flight control laws
from getting into non-symmetric upset conditions. The upset maneuvers
described in AC 25-7B, Change 1, section 32, paragraphs c(3)(a) and (c)
may be used to comply with this requirement.
3. Detected loss of the high-speed protection function must be less
than 10-3 per flight hour.
4. Failures of the system must be annunciated to the pilots. Flight
manual instructions must be provided that reduce the maximum operating
speeds. The new operating speeds, Vmax/Mmax, must
be reduced to a value that maintains a speed margin between these
speeds and VD/MD that is consistent with showing
compliance with Sec. 25.335(b) without the benefit of the high-speed
protection system.
5. Dispatch of the airplane with the high-speed protection system
inoperative could be allowed under an approved minimum equipment list
that would require flight manual instructions to indicate reduced
maximum operating speeds, as described in paragraph (4). In addition,
the cockpit display of the reduced operating speeds, as well as the
overspeed warning for exceeding those speeds, must be equivalent to
that of the normal airplane with the high-speed protection system
operative. Also, it must be shown that no additional hazards are
introduced with the high-speed protection system inoperative.
Issued in Renton, Washington, on October 11, 2012.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2012-25605 Filed 10-17-12; 8:45 am]
BILLING CODE 4910-13-P