Document ID: FAA-2012-1119-0001
Agency: faa
Document Type: Rule
Title: Special Conditions: Airbus Model A318, A319, A320, and A321 Series Airplanes; Design Dive Speed
Posted Date: 2012-10-18T04:00Z

[Federal Register Volume 77, Number 202 (Thursday, October 18, 2012)]
[Rules and Regulations]
[Pages 64029-64031]
From the Federal Register Online via the Government Printing 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