# [Amended]
**AGENCY:**
Federal Aviation Administration (FAA), DOT.
**ACTION:**
Final rule.
**SUMMARY:**
We are adopting a new airworthiness directive (AD) for certain Model MD-90-30 airplanes. This AD requires inspecting for corrosion of the retract cylinder support fitting for the main landing gear (MLG) and the mating bore for the support fitting in the MLG trunnion fitting, performing corrective actions if necessary, and replacing cadmium-plated retract cylinder support bushings and bearings. This AD results from reports of the retract cylinder support fitting for the MLG failing during gear extension and subsequently damaging the hydraulic system. We are issuing this AD to prevent corrosion and damage that could compromise the integrity of the retract cylinder support fitting for the MLG, which could adversely affect the airplane's safe landing.
**DATES:**
This AD is effective September 22, 2010.
The Director of the Federal Register approved the incorporation by reference of a certain publication listed in the AD as of September 22, 2010.
**ADDRESSES:**
For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, 3855 Lakewood Boulevard, MC D800-0019, Long Beach, California 90846-0001; telephone 206-544-5000, extension 2; fax 206-766-5683; e-mail *[email protected];* Internet *https://www.myboeingfleet.com* .
**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 800-647-5527) 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 (562) 627-5233; fax (562) 627-5210.
**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 certain Model MD-90-30 airplanes. That NPRM was published in the *Federal Register* on April 26, 2010 (75 FR 21528). That NPRM proposed to require inspecting for corrosion of the retract cylinder support fitting for the main landing gear (MLG) and the mating bore for the support fitting in the MLG trunnion fitting, performing corrective actions if necessary, and replacing cadmium-plated retract cylinder support bushings and bearings.
**Comments**
We gave the public the opportunity to participate in developing this AD. We received no comments on the NPRM or on the determination of the cost to the public.
**Conclusion**
We reviewed the relevant data and determined that air safety and the public interest require adopting the AD as proposed.
**Costs of Compliance**
We estimate that this AD affects 16 airplanes of U.S. registry. The following table provides the estimated costs for U.S. operators to comply with this AD.
| Action | Work hours | Average labor rate per hour | Parts | Cost per product | Number of U.S.-registered | Fleet cost |
| --- | --- | --- | --- | --- | --- | --- |
| Inspection | 1 | $85 | $0 | $85 | 16 | $1,360 |
| Replacement | 8 | 85 | 24,580 | 25,260 | 16 | 404,160 |
**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:
**14 CFR Part 39**
**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.
**14 CFR Part 39**
§ 39.13
2. The FAA amends § 39.13 by adding the following new AD:
*2010-16-11 McDonnell Douglas Corporation:* Amendment 39-16388. Docket No. FAA-2010-0433; Directorate Identifier 2009-NM-117-AD.
**Effective Date**
(a) This airworthiness directive (AD) is effective September 22, 2010.
**Affected ADs**
(b) None.
**Applicability**
(c) This AD applies to McDonnell Douglas Corporation Model MD-90-30 airplanes, certificated in any category, as identified in Boeing Service Bulletin MD90-57-016, Revision 2, dated April 28, 2006.
**Subject**
(d) Air Transport Association (ATA) of America Code 57: Wings.
**Unsafe Condition**
(e) This AD results from reports of the retract cylinder support fitting for the main landing gear (MLG) failing during gear extension, and subsequently damaging the hydraulic system. The Federal Aviation Administration is issuing this AD to prevent corrosion and damage that could compromise the integrity of the retract cylinder support fitting for the MLG, which could adversely affect the airplane's safe landing.
**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.
**Inspection and Corrective Actions**
(g) Before the accumulation of 30,000 total flight hours, or within 15,000 flight hours after the effective date of this AD, whichever occurs later, do a general visual inspection of the retract cylinder support fitting for the MLG and the mating bore in the MLG trunnion fitting for corrosion, install bushings and bearings without cadmium plating in the bore, and do all applicable corrective actions, in accordance with Configuration 1 of the Accomplishment Instructions of Boeing Service Bulletin MD90-57-016, Revision 2, dated April 28, 2006. Do all applicable corrective actions before further flight.
**Note 1:**
For the purposes of this AD, a general visual inspection is: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to ensure visual access to all surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.”
(h) Doing a general visual inspection, installing bushings and bearings, and doing all applicable corrective actions is also acceptable for compliance with the requirements of paragraph (g) of this AD if done before the effective date of this AD in accordance with the Accomplishment Instructions of Boeing Service Bulletin MD90-57-016, Revision 1, dated October 26, 2005.
(i) Doing a general visual inspection, installing bushings and bearings, and doing all applicable corrective actions is also acceptable for compliance with the requirements of paragraph (g) of this AD if done before the effective date of this AD in accordance with the Accomplishment Instructions of Boeing Service Bulletin MD90-57-016, dated September 18, 2002, provided that before the accumulation of 30,000 total flight hours, or within 15,000 flight hours after the effective date of this AD, whichever occurs later, electroless nickel fittings are installed, and bushings and bearings without cadmium plating in the bore are installed in accordance with the Accomplishment Instructions of any of the service bulletins listed in Table 1 of this AD.
| Document | Revision | Date | Incorporated by |
| --- | --- | --- | --- |
| Boeing Service Bulletin MD90-57-016 | 1 | October 26, 2005 | No. |
| Boeing Service Bulletin MD90-57-016 | 2 | April 28, 2006 | Yes. |
**Alternative Methods of Compliance (AMOCs)**
(j)(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 (562) 627-5233; fax (562) 627-5210.
(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 Boeing Commercial Airplanes Organization Designation Authorization (ODA) 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**
(k) You must use Boeing Service Bulletin MD90-57-016, Revision 2, dated April 28, 2006, 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, Attention: Data & Services Management, 3855 Lakewood Boulevard, MC D800-0019, Long Beach, California 90846-0001; telephone 206-544-5000, extension 2; fax 206-766-5683; e-mail *[email protected];* Internet *https://www.myboeingfleet.com* .
(3) You may review copies of the 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.
(4) You may also review copies of the service information that is incorporated by reference 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 July 28, 2010.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification Service.