
[Federal Register: April 7, 2008 (Volume 73, Number 67)]
[Proposed Rules]               
[Page 18722-18725]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr07ap08-14]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0406; Directorate Identifier 2007-NM-196-AD]
RIN 2120-AA64

 
Airworthiness Directives; Airbus Model A310 Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

[[Page 18723]]


ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for the 
products listed above that would supersede an existing AD. This 
proposed AD results from mandatory continuing airworthiness information 
(MCAI) originated by an aviation authority of another country to 
identify and correct an unsafe condition on an aviation product. The 
MCAI describes the unsafe condition as:

    During routine visual inspection, a crack has been found in the 
wing MLG (main landing gear) rib 5 forward attachment lug on two 
A310 in-service aircraft. Laboratory examination of one of the 
cracked ribs confirmed that the crack is due to the presence of 
pitting corrosion in the forward lug holes. Also on both aircraft 
medium to heavy corrosion was found in the forward lugs on the 
opposite wing after removal of the bushes. This situation if not 
detected, could affect the structural integrity of the MLG 
attachment. * * *
* * * * *
    The proposed AD would require actions that are intended to address 
the unsafe condition described in the MCAI.

DATES: We must receive comments on this proposed AD by May 7, 2008.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Portal: Go to http://
www.regulations.gov. Follow the instructions for submitting comments.
     Fax: (202) 493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
     Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-40, 1200 New 
Jersey Avenue, SE., Washington, DC, between 9 a.m. and 5 p.m., Monday 
through Friday, except Federal holidays.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the Docket Operations office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this proposed AD, the regulatory 
evaluation, any comments received, and other information. The street 
address for the Docket Operations office (telephone (800) 647-5527) is 
in the ADDRESSES section. Comments will be available in the AD docket 
shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Tom Stafford, Aerospace Engineer, 
International Branch, ANM-116, Transport Airplane Directorate, FAA, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
227-1622; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include ``Docket No. FAA-2008-0406; 
Directorate Identifier 2007-NM-196-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD based on those comments.
    We will post all comments we receive, without change, to http://
www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    On December 7, 2006, we issued AD 2007-02-09, Amendment 39-14896 
(72 FR 2612, January 22, 2007). That AD required actions intended to 
address an unsafe condition on the products listed above.
    Since we issued AD 2007-02-09, the type certificate holder has 
developed a new inspection using ultrasonic techniques. We have 
determined that the existing AD must be superseded to add repair or 
replacement of cracked main landing gear (MLG) Rib 5, provide the new 
inspection as an option, and reduce the applicability of the AD to 
exclude airplanes on which Airbus Service Bulletin A310-57-2090 has 
been done.
    The European Aviation Safety Agency (EASA), which is the Technical 
Agent for the Member States of the European Community, has issued EASA 
Airworthiness Directive 2007-0195, dated July 19, 2007 (referred to 
after this as ``the MCAI''), to correct an unsafe condition for the 
specified products. The MCAI states:

    During routine visual inspection, a crack has been found in the 
wing MLG (main landing gear) rib 5 forward attachment lug on two 
A310 in-service aircraft. Laboratory examination of one of the 
cracked ribs confirmed that the crack is due to the presence of 
pitting corrosion in the forward lug holes. Also on both aircraft 
medium to heavy corrosion was found in the forward lugs on the 
opposite wing after removal of the bushes. This situation if not 
detected, could affect the structural integrity of the MLG 
attachment. As an interim measure, Airbus published Alert Service 
Bulletin (ASB) A310-57A2088 to introduce a repetitive detailed 
visual inspection (DVI) of the forward attachment lug of MLG Rib 5. 
EASA issued Emergency Airworthiness Directive (EAD) 2006-0335-E 
[which corresponds to FAA AD 2007-02-09] to require the 
accomplishment of this repetitive DVI.

    In order to ensure the detection of any crack at an early stage 
in the forward lug of the RH (right-hand) and LH (left-hand) MLG Rib 
5 aft bearing attachment, the Type Certificate holder has developed 
a new inspection by means of ultrasonic method. For the reasons 
described above, this new inspection program is rendered mandatory 
by this AD, which cancels and replaces the requirement of EAD 2006-
0335-E.

    The corrective action includes repairing or replacing MLG Rib 5, as 
applicable. You may obtain further information by examining the MCAI in 
the AD docket.

Relevant Service Information

    Airbus has issued Service Bulletins A310-57-2090, Revision 01, 
dated December 19, 2007, and A310-57-2091, including Appendix 01, dated 
May 22, 2007. The actions described in this service information are 
intended to correct the unsafe condition identified in the MCAI.

FAA's Determination and Requirements of This Proposed AD

    This product has been approved by the aviation authority of another 
country, and is approved for operation in the United States. Pursuant 
to our bilateral agreement with the State of Design Authority, we have 
been notified of the unsafe condition described in the MCAI and service 
information referenced above. We are proposing this AD because we 
evaluated all pertinent information and determined an unsafe condition 
exists and is likely to exist or develop on other products of the same 
type design.

Differences Between This AD and the MCAI or Service Information

    We have reviewed the MCAI and related service information and, in 
general, agree with their substance. But we might have found it 
necessary to use different words from those in the MCAI to ensure the 
AD is clear for U.S. operators and is enforceable. In making these 
changes, we do not intend to differ substantively from the information 
provided in the MCAI and related service information.
    We might also have proposed different actions in this AD from those 
in the MCAI in order to follow FAA

[[Page 18724]]

policies. Any such differences are highlighted in a NOTE within the 
proposed AD.

Costs of Compliance

    Based on the service information, we estimate that this proposed AD 
would affect about 68 products of U.S. registry. We also estimate that 
it would take about 5 work-hours per product to comply with the basic 
requirements of this proposed AD. The average labor rate is $80 per 
work-hour. Based on these figures, we estimate the cost of the proposed 
AD on U.S. operators to be $27,200, or $400 per product.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. ``Subtitle VII: Aviation 
Programs,'' describes in more detail the scope of the Agency's 
authority.
    We are issuing this rulemaking under the authority described in 
``Subtitle VII, Part A, Subpart III, Section 44701: General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would not 
have a substantial direct effect 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.
    For the reasons discussed above, I certify this proposed 
regulation:
    1. Is not a ``significant regulatory action'' under Executive Order 
12866;
    2. Is not a ``significant rule'' under the DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979); and
    3. Will not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this proposed AD and placed it in the AD docket.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec.  39.13  [Amended]

    2. The FAA amends Sec.  39.13 by removing Amendment 39-14896 (72 FR 
2612, January 22, 2007) and adding the following new AD:

Airbus: Docket No. FAA-2008-0406; Directorate Identifier 2007-NM-
196-AD.

Comments Due Date

    (a) We must receive comments by May 7, 2008.

Affected ADs

    (b) The proposed AD supersedes AD 2007-02-09, Amendment 39-
14896.

Applicability

    (c) This AD applies to Airbus Model A310 airplanes, certificated 
in any category, all certified models, all serial numbers; except 
for those where LH (left-hand) and RH (right-hand) wing MLG (main 
landing gear) rib 5 forward lugs have been repaired by installation 
of oversized interference fit bushings as per Airbus Repair 
Instruction R57249121, or which have had Airbus Service Bulletin 
A310-57-2090 (AIRBUS modification 13329) embodied in service.

Subject

    (d) Air Transport Association (ATA) of America Code 57: Wings.

Reason

    (e) The mandatory continuing airworthiness information (MCAI) 
states:
    During routine visual inspection, a crack has been found in the 
wing MLG (main landing gear) rib 5 forward attachment lug on two 
A310 in-service aircraft. Laboratory examination of one of the 
cracked ribs confirmed that the crack is due to the presence of 
pitting corrosion in the forward lug holes. Also on both aircraft 
medium to heavy corrosion was found in the forward lugs on the 
opposite wing after removal of the bushes. This situation if not 
detected, could affect the structural integrity of the MLG 
attachment. As an interim measure, Airbus published Alert Service 
Bulletin (ASB) A310-57A2088 to introduce a repetitive detailed 
visual inspection (DVI) of the forward attachment lug of MLG Rib 5. 
EASA issued Emergency Airworthiness Directive (EAD) 2006-0335-E 
[which corresponds to FAA AD 2007-02-09] to require the 
accomplishment of this repetitive DVI.
    In order to ensure the detection of any crack at an early stage 
in the forward lug of the RH (right-hand) and LH (left-hand) MLG Rib 
5 aft bearing attachment, the Type Certificate holder has developed 
a new inspection by means of ultrasonic method. For the reasons 
described above, this new inspection program is rendered mandatory 
by this AD, which cancels and replaces the requirement of EAD 2006-
0335-E.
    The corrective action includes repairing or replacing MLG Rib 5, 
as applicable.

Restatement of Requirements of AD 2007-02-09

    (f) Unless already done, do the following actions specified in 
paragraphs (f)(1), (f)(2), and (f)(3) of this AD in accordance with 
the instructions defined in Airbus Service Bulletin A310-57A2088, 
dated November 6, 2006.
    (1) Before the accumulation of 12,000 total flight cycles, or 
within 14 days after February 6, 2007 (the effective date of AD 
2007-02-09), whichever occurs later: Perform a detailed visual 
inspection of the LH and RH wing MLG rib 5 aft bearing forward lugs.
    (2) If any crack is detected at LH and/or RH aft bearing forward 
lug, contact Airbus and proceed with the replacement before next 
flight.
    (3) Repeat the inspection at intervals not exceeding 100 flight 
cycles.

New Requirements of this AD: Actions and Compliance

    (g) Unless already done, before the accumulation of 12,000 total 
flight cycles or before the accumulation of 12,000 flight cycles on 
MLG Rib 5, or within 14 days after the effective date of this AD, 
whichever occurs latest: Perform either a detailed visual inspection 
(DVI) or an ultrasonic inspection of the LH and RH MLG Rib 5 aft 
bearing forward lug for cracks, in accordance with the instructions 
defined in Airbus Service Bulletin A310-57-2091, including Appendix 
01, dated May 22, 2007. If a MLG Rib 5 has been replaced on one side 
only, then the RH and LH must be considered separately. Doing this 
inspection ends the requirements of paragraph (f) for that MLG Rib 5 
only.

    Note 1: The ultrasonic inspection will detect any crack at an 
early stage and will limit the risk of extensive repairs. This 
earlier crack detection is not possible with the DVI.

    (1) If no crack is detected during any inspection required by 
paragraph (g) of this AD: Repeat the applicable inspection at the 
time specified in paragraph (g)(1)(i) or (g)(1)(ii) of this AD.
    (i) Repeat the DVI thereafter at intervals not to exceed 100 
flight cycles.
    (ii) Repeat the ultrasonic inspection thereafter at intervals 
not to exceed 825 flight cycles.
    (2) Replacement of the MLG Rib 5 in accordance with the 
instructions defined in Airbus Service Bulletin A310-57-2090, 
Revision 01, dated December 19, 2007, ends the repetitive 
inspections required by paragraph (g)(1) of this AD for that MLG Rib 
5 only.
    (3) If any crack is detected during the DVI required by 
paragraph (g) of this AD: Before further flight, contact Airbus for 
replacement

[[Page 18725]]

instructions and replace before further flight. If MLG Rib 5 is not 
replaced in accordance with the instructions defined in Airbus 
Service Bulletin A310-57-2090, Revision 01, dated December 19, 2007; 
repeat the applicable inspection in paragraph (g) of this AD at the 
time specified in the applicable paragraph.
    (4) If any crack is detected during the ultrasonic inspection 
required by paragraph (g) of this AD, before further flight, 
accomplish the actions specified in paragraphs (g)(4)(i) or 
(g)(4)(ii) of this AD, as applicable.
    (i) If any crack is not visible on MLG Rib 5: Before further 
flight, repair MLG Rib 5 using Repair Instruction R572-49121, Issue 
C, dated May 2007. After embodiment of Repair Instruction R572-
49121, no further actions are required by this AD and Airbus Service 
Bulletin A310-57-2091, including Appendix 01, dated May 22, 2007, 
for that MLG Rib 5 only.
    (ii) If any crack is visible on MLG Rib 5: Before further 
flight, contact Airbus for rib replacement instructions, and replace 
before further flight. If MLG Rib 5 is not replaced in accordance 
with the instructions defined in Airbus Service Bulletin A310-57-
2090, Revision 01, dated December 19, 2007, repeat the applicable 
inspection in paragraph (g) of this AD at the time specified. 
Accomplishing the replacement defined in Airbus Service Bulletin 
A310-57-2090 ends the repetitive inspections required by paragraph 
(g)(1) of this AD for that MLG Rib 5 only.

FAA AD Differences

    Note 2: This AD differs from the MCAI and/or service information 
as follows:
    Although the MCAI or service information allows flight with 
cracks on aft bearing forward lugs for a certain period of time, 
this AD requires replacing MLG Rib 5 before further flight if any 
crack is found.
    Although the MCAI or service information specifies submitting an 
inspection report sheet to Airbus, this AD would not require that 
action.

Other FAA AD Provisions

    (h) The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, 
International Branch, ANM-116, Transport Airplane Directorate, FAA, 
has the authority to approve AMOCs for this AD, if requested using 
the procedures found in 14 CFR 39.19. Send information to ATTN: Tom 
Stafford, Aerospace Engineer, International Branch, ANM-116, 
Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, 
Washington 98057-3356; telephone (425) 227-1622; fax (425) 227-1149. 
Before using any approved AMOC on any airplane to which the AMOC 
applies, notify your appropriate principal inspector (PI) in the FAA 
Flight Standards District Office (FSDO), or lacking a PI, your local 
FSDO.
    (2) Airworthy Product: For any requirement in this AD to obtain 
corrective actions from a manufacturer or other source, use these 
actions if they are FAA-approved. Corrective actions are considered 
FAA-approved if they are approved by the State of Design Authority 
(or their delegated agent). You are required to assure the product 
is airworthy before it is returned to service.
    (3) Reporting Requirements: For any reporting requirement in 
this AD, under the provisions of the Paperwork Reduction Act, the 
Office of Management and Budget (OMB) has approved the information 
collection requirements and has assigned OMB Control Number 2120-
0056.

Related Information

    (i) Refer to MCAI EASA Airworthiness Directive 2007-0195, dated 
July 19, 2007, and Airbus Service Bulletins A310-57-2090, Revision 
01, dated December 19, 2007, and A310-57-2091, including Appendix 
01, dated May 22, 2007, for related information.

    Issued in Renton, Washington, on March 27, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E8-7163 Filed 4-4-08; 8:45 am]

BILLING CODE 4910-13-P
