E8-385. Airworthiness Directives; McDonnell Douglas Model DC-10-10, DC-10-10F, DC-10-15, and MD-10-10F Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to adopt a new airworthiness directive (AD) for certain McDonnell Douglas Model DC-10-10, DC-10-10F, DC-10-15, and MD-10-10F airplanes. This proposed AD would require repetitive inspections for the presence of stray nickel or chrome plating deposits on the air filler valve bore of certain main landing gear (MLG) shock strut cylinders, and if necessary, related investigative and corrective actions. Doing the corrective action would terminate the repetitive inspections. This proposed AD results from a report of a left MLG collapse during landing rollout. We are proposing this AD to detect and correct stray nickel and chrome plating deposits, corrosion, and cracking of the air filler valve bore on the MLG cylinder, which could result in landing gear failure, significant damage to the airplane, and injury to personnel.

DATES:

We must receive comments on this proposed AD by February 28, 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: [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 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 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:

Maureen Moreland, 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-2008-0015; Directorate Identifier 2007-NM-328-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 received a report that one McDonnell Douglas Model MD-10-10 airplane experienced a left main landing gear (MLG) collapse during landing rollout, which was caused by combined fatigue and stress corrosion cracking failure of the MLG shock strut cylinder assembly. Metallurgical analysis has determined that the origin of the fracture was located in the bore of the air filler valve port located on the aft side of the MLG cylinder. The primary crack initiation point was in an area of stray nickel plating deposits on the bore. A secondary origination of the crack was initiated from a shallow corrosion pit located at the opposite side of the bore to the primary initiation point. Stray nickel or chrome plating deposits, corrosion, or cracking in the air filler valve bore of the MLG cylinder, if not corrected, could result in landing gear failure, significant damage to the airplane, and injury to personnel.

Relevant Service Information

We have reviewed Boeing Alert Service Bulletin DC10-32A259, dated October 30, 2007. The service bulletin describes procedures for repetitive video probe inspections to detect the presence of stray nickel or chrome plating deposits on the air filler valve bore of certain main landing gear (MLG) shock strut cylinders, and if necessary, related investigative and corrective actions. The related investigative actions include a video probe inspection for corrosion of the air filler valve bore in the MLG shock strut cylinder and an eddy current inspection for cracking of the air filler valve bore. The corrective actions include repair of the air filler valve bore of the MLG shock strut cylinder, removal of corrosion, and replacement of the MLG cylinder. The service bulletin specifies that doing the repair or replacement ends the repetitive inspections for that MLG shock strut cylinder only.

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 75 airplanes of U.S. registry. The following table provides the estimated costs for U.S. operators to comply with this proposed AD.

Estimated Costs

Action	Work hours	Average labor rate per hour	Cost per product	Number of U.S.-registered airplanes	Fleet cost
Inspection	4	$80	$320, per inspection cycle	75	$24,000, 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 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
• 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-2008-0015; Directorate Identifier 2007-NM-328-AD.

Comments Due Date

(a) We must receive comments by February 28, 2008.

Affected ADs

(b) None.

Applicability

(c) This AD applies to McDonnell Douglas Model DC-10-10, DC-10-10F, DC-10-15, and MD-10-10F airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin DC10-32A259, dated October 30, 2007.

Unsafe Condition

(d) This AD results from a report of a left main landing gear (MLG) collapse during landing rollout. We are issuing this AD to detect and correct stray nickel and chrome plating deposits, corrosion, and cracking of the air filler valve bore on the MLG cylinder, which could result in landing gear failure, significant damage to the airplane, and injury to personnel.

Compliance

(e) Comply with this AD within the compliance times specified, unless already done.

Inspections and Corrective Actions

(f) At the applicable time specified in paragraph (f)(1), (f)(2), or (f)(3) of this AD, do a video probe inspection for the presence of stray nickel or chrome plating deposits on the air filler valve bore of the MLG shock strut cylinders, and before further flight, do all applicable related investigative and corrective actions, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin DC10-32A259, dated October 30, 2007. Repeat the video probe inspection thereafter at intervals not to exceed 2,400 flight cycles or 20 months, whichever occurs first. Accomplishment of the repair specified in Part 2 of the Accomplishment Instructions of the service bulletin or the replacement specified in Part 3 of the Accomplishment Instructions of the service bulletin terminates the repetitive inspections for that MLG shock strut cylinder.

(1) For passenger airplanes: Within 24 months after the effective date of this AD.

(2) For freighter airplanes with MLG cylinders that have accumulated fewer than 7,200 flight cycles in a freighter configuration as of the effective date of this AD: Within 24 months after the effective date of this AD.

(3) For freighter airplanes with MLG cylinders that have accumulated 7,200 flight cycles or more in a freighter configuration as of the effective date of this AD: Within 6 months after the effective date of this AD.

Parts Installation

(g) As of the effective date of this AD, no person may install a MLG shock strut cylinder assembly, part number ARG7002-1, -501, -503, or -505, on any airplane, unless the air filler valve bore hole has been oversized and closing action has been accomplished in accordance with Boeing Alert Service Bulletin DC10-32A259, dated October 30, 2007, and the MLG shock strut cylinder assembly has been permanently identified with part number SB10320259-3 adjacent to the existing ARG7002 part number.

Alternative Methods of Compliance (AMOCs)

(h)(1) The Manager, Los Angeles Aircraft Certification Office (ACO), FAA, ATTN: Maureen Moreland, Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Los Angeles ACO, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone [phone]; fax [phone]; has the authority to approve AMOCs for this AD, if requested using 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.

Issued in Renton, Washington, on December 26, 2007.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.