2013-23269. Airworthiness Directives; Airbus Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to adopt a new airworthiness directive (AD) for all Airbus Model A318, A319, A320, and A321 series airplanes. This proposed AD was prompted by a report that an investigation showed that when a certain combination of a target/proximity sensor serial number is installed on a flap interconnecting strut, a “target FAR” signal cannot be detected when it reaches the mechanical end stop of the interconnecting strut. This proposed AD would require an inspection to determine the part number (P/N) of the interconnecting struts installed on the wings, identifying the P/N and the serial number (S/N) of the associated target and proximity sensor if applicable, and replacing or re-identifying the flap interconnecting strut if applicable. We are proposing this AD to detect and correct a latent failure of the flap down drive disconnection due to an already-failed interconnecting strut sensor, which could result in asymmetric flap panel movement and consequent loss of control of the airplane.

DATES:

We must receive comments on this proposed AD by November 12, 2013.

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: [phone].
• 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 W12-140, 1200 New Jersey Avenue SE., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this proposed AD, contact Airbus, Airworthiness Office—EAS, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone [phone]; fax [phone]; email [e-mail]; Internet http://www.airbus.com. You may review copies of the referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, WA. For information on the availability of this material at the FAA, call 425-227-1221.

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 [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Sanjay Ralhan, Aerospace Engineer, International Branch, ANM-116, Transport Airplane Directorate, FAA, 1601 Lind Avenue SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone].

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-2013-0791; Directorate Identifier 2012-NM-026-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

The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community, has issued EASA Airworthiness Directive 2012-0012, dated January 23, 2012 (referred to after this as “the MCAI”), to correct an unsafe condition for the specified products. The MCAI states:

The flap interconnecting strut is a safety device of the High Lift System which acts as an alternative load path from one flap surface to another in case of a flap drive system disconnection. In such a failure case, the installed proximity provide information to the slat flap control computer (SFCC) and the operation of the flap drive system is inhibited.

A recent engineering investigation has shown that, when a certain combination of target/sensor serial number (s/n) is installed on a flap interconnecting strut, a “target FAR” signal cannot be detected when reaching the mechanical end stop of the interconnecting strut.

This condition, if not corrected, could cause a flap down drive disconnection to remain undetected, due to an already-failed interconnecting strut sensor, potentially resulting in asymmetric flap panel movement and consequent loss of control of the aeroplane.

For the reason described above, this [EASA] AD requires the identification and replacement [or re-identifying] of struts that have a certain target/sensor s/n combination installed.

You may obtain further information by examining the MCAI in the AD docket.

Relevant Service Information

Airbus has issued Service Bulletin A320-27-1206, Revision 01, dated October 10, 2011. 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

Although note 1 of the EASA Airworthiness Directive 2012-0012, dated January 23, 2012, allows flight for 50 flight cycles after the inspection of the flap down drive if an interconnecting strut cannot be replaced, this proposed AD does not include this exception.

Costs of Compliance

We estimate that this proposed AD affects 755 airplanes of U.S. registry.

We estimate the following costs to comply with this proposed AD:

Estimated Costs

Action	Labor cost	Parts cost	Cost per product	Cost on U.S. operators
Inspection and Re-identification	8 work-hours × $85 per hour = $680 per inspection cycle	$0	$680 per inspection cycle	$513,400 per inspection cycle.

We estimate the following costs to do any necessary replacements that would be required based on the results of the proposed inspection. We have no way of determining the number of aircraft that might need these replacements:

On-condition Costs

Action	Labor cost	Parts cost	Cost per product
Replacement	10 work-hours × $85 per hour = $850	$0	$850

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);

3. Will not affect intrastate aviation in Alaska; and

4. 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
• Incorporation by reference
• 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.

§ 39.13

[Amended]

2. The FAA amends § 39.13 by adding the following new AD:

Airbus: Docket No. FAA-2013-0791; Directorate Identifier 2012-NM-026-AD.

(a) Comments Due Date

We must receive comments by November 12, 2013.

(b) Affected ADs

None.

(c) Applicability

This AD applies to all Airbus Model A318-111, -112, -121, and -122 airplanes; Model A319-111, -112, -113, -114, -115, -131, -132, and -133 airplanes; Model A320-111, -211, -212, -214, -231, -232, and -233 airplanes; and Model A321-111, -112, -131, -211, -212, -213, -231, and -232 airplanes; certificated in any category; all manufacturer serial numbers.

(d) Subject

Air Transport Association (ATA) of America Code 27, Flight controls.

(e) Reason

This AD was prompted by a report that an investigation showed that when a certain combination of a target/proximity sensor serial number is installed on a flap interconnecting strut, a “target FAR” signal cannot be detected when reaching the mechanical end stop of the interconnecting strut. We are issuing this AD to detect and correct a latent failure of the flap down drive disconnection due to an already-failed interconnecting strut sensor, which could result in asymmetric flap panel movement and consequent loss of control of the airplane.

(f) Compliance

You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

(g) Inspection To Determine the Part Number of the Interconnecting Struts

Within 8,000 flight hours after the effective date of this AD, inspect to determine the part number of the interconnecting struts installed on both the left-hand (LH) and right-hand (RH) wings of the airplane, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-27-1206, Revision 01, dated October 10, 2011. A review of the airplane maintenance records is acceptable for determining the part number of the installed interconnecting struts, in lieu of the inspection, if the part number of the installed interconnecting struts, and the part number and the serial number of the associated target and proximity sensor, can be conclusively determined from that review.

(1) Airplanes on which Airbus modification 27956 has been embodied in production, on which no interconnecting strut having a part number specified in figure 1 to paragraph (g) of this AD, and has been replaced since the airplane's first flight: No further work is required by paragraph (g) of this AD.

(2) If, during the inspection required by paragraph (g) of this AD, any interconnecting strut is installed with a part number specified in figure 1 to paragraph (g) of this AD: Within 8,000 flight hours after the effective date of this AD, determine the part number and the serial number of the associated target and proximity sensor.

Interconnecting strut part numbers

D5757030500000

D5757030500100

D5757030500200

D5757030500600

D5757030500800

D5757030501000

D5757030501200

D5757032200000

(i) For airplanes having conditions specified in paragraphs (g)(2)(i)(A), (g)(2)(i)(B), (g)(2)(i)(C), and (g)(2)(i)(D) of this AD: Before further flight, replace the interconnecting strut with a serviceable unit, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-27-1206, Revision 01, dated October 10, 2011. For the purpose of this AD, a serviceable interconnecting strut is a unit which has been determined to be in compliance with the requirements of this AD.

(A) A target part number (P/N) ABS0121-13 or P/N 8-536-01, and

(B) A target serial number lower than 1600, or a target serial number that is unreadable, and

(C) A proximity sensor having P/N ABS0121-31 or P/N 8-372-04, and

(D) A proximity sensor having a serial number between C59198 and C59435, or a serial number (S/N) C500000 or higher.

(ii) For a target having S/N 1600 or higher and target P/N ABS0121-13 or P/N 8-536-01: Within 8,000 flight hours after the effective date of this AD, re-identify the interconnecting strut, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-27-1206, Revision 01, dated October 10, 2011.

(h) Parts Installation Prohibition

As of the effective date of this AD, no person may install an interconnecting strut with a part number specified in figure 1 to paragraph (g) of this AD, on any airplane, except for parts identified in paragraph (g)(2)(ii) of this AD, provided that the actions in paragraph (g)(2)(ii) are done.

(i) Credit for Previous Actions

This paragraph provides credit for the actions required by paragraph (g) of this AD, if those actions were performed before the effective date of this AD using Airbus Service Bulletin A320-27-1206, dated January 28, 2011, and if additional work has been accomplished using Airbus Service Bulletin A320-27-1206, Revision 01, dated October 10, 2011.

(j) Other FAA AD Provisions

The following provisions also apply to this AD:

(1) Alternative Methods of Compliance (AMOCs): The Manager, International Branch, ANM-116, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the International Branch, send it to ATTN: Sanjay Ralhan, Aerospace Engineer, International Branch, ANM-116, Transport Airplane Directorate, FAA, 1601 Lind Avenue SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone]. Information may be emailed to: [e-mail]. Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office. The AMOC approval letter must specifically reference this AD.

(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.

(k) Related Information

(1) Refer to Mandatory Continuing Airworthiness Information (MCAI) EASA Airworthiness Directive 2012-0012, dated January 23, 2012, for related information, which can be found in the AD docket on the Internet at http://www.regulations.gov.

(2) For service information identified in this AD, contact Airbus, Airworthiness Office—EAS, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone [phone]; fax [phone]; email [e-mail]; Internet http://www.airbus.com. You may review copies of the referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, WA. For information on the availability of this material at the FAA, call 425-227-1221.

Issued in Renton, Washington, on September 13, 2013.

Jeffrey E. Duven,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.