E9-21338. Airworthiness Directives; McDonnell Douglas Model MD-90-30 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 McDonnell Douglas Model MD-90-30 airplanes. This proposed AD would require repetitive inspections for cracking of the overwing frames at stations 883, 902, 924, 943, and 962, left and right sides, and corrective actions if necessary. This proposed AD results from reports of cracked overwing frames. We are proposing this AD to detect and correct such cracking, which could sever the frame, increase the loading of adjacent frames, and result in damage to adjacent structure and loss of overall structural integrity of the airplane.

DATES:

We must receive comments on this proposed AD by October 19, 2009.

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 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this proposed AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, 3855 Lakewood Boulevard, MC D800-0019, Long Beach, California 90846-0001; telephone [phone], extension 2; fax [phone]; e-mail [e-mail]; Internet https://www.myboeingfleet.com. You may review copies of the referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221 or 425-227-1152.

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility 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 Office (telephone [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Roger Durbin, Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; 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-2009-0783; Directorate Identifier 2009-NM-081-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 because of 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

We have received reports of cracked overwing frames at stations 845, 864, 886, and 905 on the left and right sides in the upper radius of the frame tab on McDonnell Douglas Model MD-80 series airplanes that had accumulated between 19,876 and 41,166 total flight cycles. The cracks, which originate in the upper radius of the frame inboard tab just below the floor, were caused by fatigue. This condition, if not corrected, could result in damage to adjacent structure and loss of overall structural integrity of the airplane.

The cracked overwing frames on McDonnell Douglas Model MD-80 series airplanes have the same design as those installed on Model MD-90-30 airplanes. Therefore, Model MD-90-30 airplanes may be subject to the identified unsafe condition. AD 2008-13-29, Amendment 39-15592 (73 FR 38883, July 8, 2008), addresses cracked overwing frames on McDonnell Douglas Model MD-80 series airplanes.

Relevant Service Information

We have reviewed Boeing Alert Service Bulletin MD90-53A031, dated April 10, 2009. The service bulletin describes procedures for performing repetitive general visual and high frequency eddy current inspections to detect cracking of the overwing frames at stations 883, 902, 924, 943, and 962, left and right sides. Corrective actions include a blend-out repair or replacement of the cracked overwing frame, depending on the results of the inspection. The service bulletin specifies to repeat the inspections at intervals not to exceed 5,900 flight cycles, except that for airplanes on which a replacement is done, the service bulletin specifies that the next inspection be done within 20,000 flight cycles after the replacement.

FAA's Determination and Requirements of This Proposed AD

We are proposing this AD because we evaluated all relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of the same type design. This proposed AD would require accomplishing the actions specified in the service information described previously.

Costs of Compliance

We estimate that this proposed AD would affect 16 airplanes of U.S. registry. We also estimate that it would take about 10 work-hours per product to comply with this proposed AD. The average labor rate is $80 per work-hour. Based on these figures, we estimate the cost of this proposed AD to the U.S. operators to be $12,800, or $800 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.

You can find our regulatory evaluation and the estimated costs of compliance 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:

McDonnell Douglas: Docket No. FAA-2009-0783; Directorate Identifier 2009-NM-081-AD.

Comments Due Date

(a) We must receive comments by October 19, 2009.

Affected ADs

(b) None.

Applicability

(c) This AD applies to all McDonnell Douglas Model MD-90-30 airplanes, certificated in any category.

Subject

(d) Air Transport Association (ATA) of America Code 53: Fuselage.

Unsafe Condition

(e) This AD results from reports of cracked overwing frames. We are issuing this AD to detect and correct such cracking, which could sever the frame, increase the loading of adjacent frames, and result in damage to adjacent structure and loss of overall structural integrity of the airplane.

Compliance

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

Inspections

(g) Before the accumulation of 20,000 total flight cycles, or within 60 months after the effective date of this AD, whichever occurs later: Do general visual and high frequency eddy current inspections for cracking of the overwing frames, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD90-53A031, dated April 10, 2009. Do the applicable corrective actions before further flight, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD90-53A031, dated April 10, 2009. Repeat the inspections thereafter at the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin MD90-53A031, dated April 10, 2009.

Alternative Methods of Compliance (AMOCs)

(h)(1) The Manager, Los Angeles Aircraft Certification Office (ACO), 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: Roger Durbin, Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone [phone]; fax [phone].

(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD.

(3) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD, if it is approved by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization who has been authorized by the Manager, Los Angeles ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane and the approval must specifically refer to this AD.

Issued in Renton, Washington, on August 26, 2009.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.