E8-14472. Airworthiness Directives; McDonnell Douglas Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule.

SUMMARY:

We are adopting a new airworthiness directive (AD) for all McDonnell Douglas Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 airplanes. This AD requires repetitive inspections for cracking of the overwing frames from stations 845 to 905 (MD-87 stations 731 to 791), left and right sides, and corrective actions if necessary. 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.

DATES:

This AD is effective August 12, 2008.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of August 12, 2008.

ADDRESSES:

For service information identified in this AD, contact Boeing Commercial Airplanes, Long Beach Division, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Data and Service Management, Dept. C1-L5A (D800-0024).

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 AD, the regulatory evaluation, any comments received, and other information. The address for the Docket Office (telephone [phone]) is the Document Management Facility, U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.

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:

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to all McDonnell Douglas Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 airplanes. That NPRM was published in the Federal Register on September 28, 2007 (72 FR 55111). That NPRM proposed to require repetitive inspections for cracking of the overwing frames from stations 845 to 905 (MD-87 stations 731 to 791), left and right sides, and corrective actions if necessary.

Comments

We gave the public the opportunity to participate in developing this AD. We considered the comments received.

Request To Extend Compliance Time

Air Transport Association (ATA), on behalf of its member American Airlines, states that a 24-month compliance period for the initial inspections would be overly burdensome. The commenters request that we extend the compliance time to 48 months so operators can integrate the required actions with planned heavy maintenance visits. The commenters add that we did not consider the size of the fleet and the availability of parts when we determined the compliance period. American Airlines finds that a longer compliance time can be justified by applying statistically based risk analysis methods and accounting for the effect of flight cycles.

We do not agree to extend the compliance time. We have no data or analysis to support such an extension of the compliance period. For airplanes that have accumulated more than 20,000 total flight cycles, the extent of damage already accumulated on the affected fuselage frames cannot be predetermined, so accounting for subsequent flight cycles will provide no benefit. The 24-month compliance period is considered appropriate in light of the characteristics of crack growth, the probability of crack initiation, and the ability of operators to integrate the required actions into established maintenance practices. Currently there are insufficient statistical or other data to justify a compliance period beyond the proposed 24 months. However, paragraph (h) of this final rule provides operators the opportunity to request an extension of the compliance time if data are presented to justify such an extension. We have not changed the final rule regarding this issue.

Request To Delay Issuance of AD Pending Parts Availability

ATA, on behalf of its member American Airlines, notes that the rate of cracking noted in early inspections suggests that the supply of available spare parts is insufficient to support completion of the proposed actions within the 24-month compliance period. Delta Air Lines also expresses concern over the availability of spare frames and reports that all its repairs done to date have been done by frame replacement with a like part.

We infer that the commenters request that we wait to issue the final rule until sufficient parts are available. We disagree with the need to delay the final rule. Boeing has arranged to have additional frames manufactured as demand builds during the 24-month compliance period. Boeing expects a sufficient supply to be available to support the AD requirements. We are proceeding with issuance of the final rule as proposed.

Request To Revise Cost Estimate

ATA, on behalf of its member Delta Air Lines, notes that the estimated work hours to do the required actions assume that access to the overwing frames is available during a scheduled maintenance visit. The commenters assert that the 4-hour labor estimate applies only when the inspection can be done during a scheduled heavy maintenance visit, when the airplane is already opened up. Delta states that, in reality, up to 67 percent of its fleet will not be due for the heavy maintenance visit during the proposed compliance time. That portion of the fleet will require special-schedule inspection visits, and add at least 16 work hours to gain access to the inspection areas.

We infer that the commenters are requesting that we revise the cost estimate provided in the NPRM. We do not agree. The cost information provided in AD actions describes only the direct costs of the specific requirements. Based on the best data available, the manufacturer provided the number of work hours to do the required actions for this AD. We recognize that, in doing the actions required by an AD, operators might incur incidental costs, such as the time necessary for access and close, in addition to the direct costs. These incidental costs can vary significantly among operators. We have not changed the final rule regarding this issue.

Conclusion

We reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting the AD as proposed.

Interim Action

We consider this AD interim action. The manufacturer is currently developing a modification that will address the unsafe condition identified in this AD. Once this modification is developed, approved, and available, we may consider additional rulemaking.

Costs of Compliance

There are about 1,189 airplanes of the affected design in the worldwide fleet. The following table provides the estimated costs for U.S. operators to comply with this AD.

Estimated Costs

Work hours	Average labor rate per hour	Parts	Cost per airplane	Number of U.S.- registered airplanes	Fleet cost
4	$80	None	$320, per inspection cycle	670	$214,400, per inspection cycle.

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

This AD will not have federalism implications under Executive Order 13132. This AD will 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 that this AD:

(1) Is not a “significant regulatory action” under Executive Order 12866,

(2) Is not a “significant rule” under 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

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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:

2008-13-29 McDonnell Douglas: Amendment 39-15592. Docket No. FAA-2007-29335; Directorate Identifier 2007-NM-045-AD.

Effective Date

(a) This airworthiness directive (AD) is effective August 12, 2008.

Affected ADs

(b) None.

Applicability

(c) This AD applies to all McDonnell Douglas Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 airplanes, certificated in any category.

Unsafe Condition

(d) 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

(e) 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

(f) Before the accumulation of 20,000 total flight cycles, or within 24 months after the effective date of this AD, whichever occurs later: Do general visual and high frequency eddy current inspections, and all applicable corrective actions, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD80-53A301, Revision 1, dated May 25, 2007. Do the applicable corrective actions before further flight after accomplishing the inspections. Repeat the inspections thereafter at applicable intervals not to exceed those specified in paragraph 1.E., “Compliance,” of the service bulletin.

Actions According to Previous Issue of Service Bulletin

(g) Inspections and related investigative and corrective actions are also acceptable for compliance with the requirements of paragraph (f) of this AD if done before the effective date of this AD in accordance with Boeing Alert Service Bulletin MD80-53A301, dated January 9, 2007.

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 in accordance with the procedures found in 14 CFR 39.19.

(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 appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO.

(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 14 CFR 25.571, Amendment 45, and the approval must specifically refer to this AD.

Material Incorporated by Reference

(i) You must use Boeing Alert Service Bulletin MD80-53A301, Revision 1, dated May 25, 2007, to do the actions required by this AD, unless the AD specifies otherwise.

(1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) For service information identified in this AD, contact Boeing Commercial Airplanes, Long Beach Division, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Data and Service Management, Dept. C1-L5A (D800-0024).

(3) You may review copies of the service information incorporated by reference at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/​federal_​register/​code_​of_​federal_​regulations/​ibr_​locations.html.

Issued in Renton, Washington, on June 8, 2008.

Michael Kaszycki,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.