E7-18447. Airworthiness Directives; McDonnell Douglas Model DC-9-81 (MD-81) and DC-9-82 (MD-82) Airplanes

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for certain McDonnell Douglas Model DC-9-81 (MD-81) and DC-9-82 (MD-82) airplanes. This proposed AD would require, for certain airplanes, inspecting for cracking of the fuselage skin at the upper corners of the forward passenger doorjamb, installing or replacing doublers as applicable, and doing applicable repairs. This proposed AD results from reports of fatigue cracking in the fuselage skin at the upper corners of the forward passenger doorjamb. We are proposing this AD to prevent cracking of the fuselage skin at the upper corners of the forward passenger doorjamb, which could lead to loss of overall structural integrity of the airplane.

DATES:

We must receive comments on this proposed AD by November 5, 2007.

ADDRESSES:

Use one of the following addresses to submit comments on this proposed AD.

• DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
• Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• 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.
• Fax: [phone].
• Hand Delivery: Room W12-140 on the ground floor of the West Building, 1200 New Jersey Avenue, SE., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

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

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 submit any relevant written data, views, or arguments regarding this proposed AD. Send your comments to an address listed in the ADDRESSES section. Include the docket number “FAA-2007-29226; Directorate Identifier 2006-NM-256-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of that Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov.

Examining the Docket

You may examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Operations office (telephone [phone]) is located on the ground level of the West Building at the DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the Docket Management System receives them.

Discussion

We have received a report that fatigue cracking has been discovered in the fuselage skin at the upper corners of the forward passenger doorjamb on certain Model DC-9/MD-80 airplanes. This condition, if not corrected, could lead to loss of overall structural integrity of the airplane.

Relevant Service Information

We have reviewed Boeing Alert Service Bulletin MD80-53A298, dated August 1, 2006. The alert service bulletin describes procedures for a low-frequency eddy current (LFEC) or a high-frequency eddy current (HFEC) inspection, depending on airplane configuration, for cracking of the fuselage skin at the upper corners of the forward passenger doorjamb; and applicable corrective actions. The compliance time for the initial inspection is before accumulating 37,500 total flight cycles, or within 3,575 flight cycles (whichever is later).

The corrective actions include:

• For Group 1, Configuration 1, airplanes on which no cracking is found: Either repeating the LFEC inspection at intervals of 3,575 flight cycles; or installing external aluminum doublers within 3,575 flight cycles after the last inspection, and doing an HFEC inspection within 28,000 flight cycles after doing the installation, and repetitively at 20,000-flight-cycle intervals.
• For Group 1, Configuration 1, airplanes on which any crack is found that is 2.0 inches or shorter in length: Repair before further flight, and do an HFEC inspection within 28,000 flight cycles after the repair, and repetitively at 20,000-flight-cycle intervals.
• For Group 1, Configuration 1, airplanes on which any crack is found that is longer than 2.0 inches; for Group 1, Configurations 2 and 3, airplanes on which any crack is found beyond the edge of the doublers; and for Group 1, Configuration 4, airplanes: Contact Boeing for repair instructions before further flight.
• For Group 1, Configuration 2, airplanes on which no crack is found beyond the edge of the steel doublers: Replace existing steel doublers with aluminum doublers, and repair upper corners within 6,000 flight cycles after the initial inspection; and do an HFEC inspection within 28,000 flight cycles after the repair, and repetitively at 20,000-flight-cycle intervals.
• For Group 1, Configuration 3, airplanes on which no cracks are found beyond the edge of the aluminum doublers: Repeat the HFEC inspection at 20,000-flight-cycle intervals.

Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other airplanes of this same type design. For this reason, we are proposing this AD, which would require accomplishing the actions specified in the service information described previously, except as discussed under “Differences Between Proposed AD and Alert Service Bulletin.”

Differences Between Proposed AD and Alert Service Bulletin

For all airplanes, the alert service bulletin specifies to contact the manufacturer for instructions on how to repair certain conditions, but this proposed AD would require repairing those conditions in one of the following ways:

• Using a method that we approve; or
• Using data that meet the certification basis of the airplane, and that have been approved by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization whom we have authorized to make those findings.

For airplane configuration 4: Where the alert service bulletin specifies to contact the manufacturer for repair instructions before further flight, to avoid unnecessarily grounding airplanes, this proposed AD would require performing repairs within 90 days after the effective date of this proposed AD.

Costs of Compliance

There are about 76 airplanes of the affected design in the worldwide fleet. This proposed AD would affect about 46 airplanes of U.S. registry. The following table provides the estimated costs for U.S. operators to comply with this proposed AD, at an average labor rate of $80 per work hour. The proposed actions vary depending upon the airplane configuration.

Estimated Costs

Action	Work hours	Parts	Cost per airplane	Fleet cost
LFEC inspection	1	None needed	$80, per inspection cycle	Up to $3,680, per inspection cycle.
HFEC inspection	1	None needed	$80, per inspection cycle	Up to $3,680, 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

We have 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 that the 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. See the ADDRESSES section for a location to examine the regulatory evaluation.

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.

§ 39.13

[Amended]

2. The Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):

McDonnell Douglas: Docket No. FAA-2007-29226; Directorate Identifier 2006-NM-256-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by November 5, 2007.

Affected ADs

(b) None.

Applicability

(c) This AD applies to McDonnell Douglas Model DC-9-81 (MD-81) and DC-9-82 (MD-82) airplanes; certificated in any category; as identified in Boeing Alert Service Bulletin MD80-53A298, dated August 1, 2006.

Unsafe Condition

(d) This AD results from a report of fatigue cracking in the fuselage skin at the upper corners of the forward passenger doorjamb. We are issuing this AD to prevent cracking of the fuselage skin at the upper corners of the forward passenger doorjamb, which could lead to 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.

Repetitive Inspections and Corrective Actions for Configuration 1, 2, and 3 Airplanes

(f) For airplanes identified as Configuration 1, 2, or 3 in Boeing Alert Service Bulletin MD80-53A298, dated August 1, 2006: At the applicable times specified in paragraph 1.E., “Compliance,” of the alert service bulletin, do a low-frequency eddy current (LFEC) or high-frequency eddy current (HFEC) inspection, as applicable, for cracking of the fuselage skin at the upper corners of the forward passenger doorjamb; and do all applicable corrective actions (repetitive inspections, installation of doublers, replacements, and repairs), except as provided by paragraph (g) of this AD. Do the actions in accordance with the Accomplishment Instructions of the alert service bulletin. Where the alert service bulletin specifies a compliance time after the date on the service bulletin, this AD requires compliance within the specified compliance time after the effective date of this AD.

Repair of Certain Conditions

(g) If any crack is found during any inspection required by paragraph (f) of this AD and Boeing Alert Service Bulletin MD80-53A298, dated August 1, 2006, specifies to contact Boeing for repair instructions: Before further flight, repair using a method approved in accordance with the procedures specified in paragraph (i) of this AD.

Corrective Action for Configuration 4 Airplanes

(h) For airplanes identified as Configuration 4 in Boeing Alert Service Bulletin MD80-53A298, dated August 1, 2006: Within 90 days after the effective date of this AD, repair using a method approved in accordance with the procedures specified in paragraph (i) of this AD.

Alternative Methods of Compliance (AMOCs)

(i)(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.

Issued in Renton, Washington, on September 10, 2007.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.