E7-16123. Airworthiness Directives; Fokker Model F28 Mark 0070 and 0100 Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:

Over the years, several Fokker 100 (F28 Mark 0100) operators reported that a MLG (main landing gear) wheel fell off during regular operation of the aircraft. These incidents occurred due to a missing spacer, which had inadvertently not been installed during a previous wheel change. Omitting the installation of the wheel spacer allows the wheel to move sideways along the axle, which subsequently leads to bearing failure, followed by loss of the wheel. * * * This condition, if not corrected, * * * could conceivably result in loss of control of the aircraft during the take-off run, landing rollout or taxiing operations. * * *

The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI.

DATES:

We must receive comments on this proposed AD by September 17, 2007.

ADDRESSES:

You may send comments by any of the following methods:

• DOT Docket Web Site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
• 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: 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.
• Federal eRulemaking Portal: http://www.regulations.gov. Follow the instructions for submitting comments.

Examining the AD 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 AD docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Tom Rodriguez, Aerospace Engineer, International Branch, ANM-116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; 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-2007-28923; Directorate Identifier 2007-NM-133-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 based on 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 we receive about this proposed AD.

Discussion

The Civil Aviation Authority—The Netherlands (CAA-NL), which is the aviation authority for the Netherlands, has issued Dutch Airworthiness Directive NL-2005-008, dated June 30, 2005 (referred to after this as “the MCAI”), to correct an unsafe condition for the specified products. The MCAI states:

Over the years, several Fokker 100 (F28 Mark 0100) operators reported that a MLG (main landing gear) wheel fell off during regular operation of the aircraft. These incidents occurred due to a missing spacer, which had inadvertently not been installed during a previous wheel change. Omitting the installation of the wheel spacer allows the wheel to move sideways along the axle, which subsequently leads to bearing failure, followed by loss of the wheel. Investigation by Fokker and Messier-Dowty has shown that two separate items, the spacer and the axle nut, can be replaced by a single axle-nut/spacer assembly, to prevent the possibility of omitting the spacer. In 1995, Messier-Dowty issued Service Bulletin (SB) F100-32-72 to make sure that the operator does not assemble the axle nut without the spacer. Fokker subsequently issued SB F100-32-096 to notify Fokker 100 operators of the (optional) Messier-Dowty SB's existence. At a later stage, Fokker revised the SB to the status of “recommended”. In spite of all this attention to the spacer problem, wheel losses are still being reported due to missing wheel nut spacers. This condition, if not corrected, may lead to further wheel loss incidents, each of which could conceivably result in loss of control of the aircraft during the take-off run, landing rollout or taxiing operations. Since a potentially unsafe condition has been identified that may exist or develop on aircraft of the same type design, this Airworthiness Directive requires the replacement of the axle-nut and spacer with an integrated axle-nut/spacer assembly. In addition, the Aircraft Maintenance Manual (AMM) and Illustrated Parts Catalogue (IPC) must be amended to prevent reversal to a separate axle-nut and spacer installation during a subsequent wheel change.

You may obtain further information by examining the MCAI in the AD docket.

Relevant Service Information

Messier-Dowty has issued Service Bulletin F100-32-72, Revision 1, dated March 5, 2007. The actions described in this service information are intended to correct the unsafe condition identified in the MCAI.

FAA's Determination and Requirements of This Proposed AD

This product has been approved by the aviation authority of another country, and is approved for operation in the United States. Pursuant to our bilateral agreement with the State of Design Authority, we have been notified of the unsafe condition described in the MCAI and service information referenced above. We are proposing this AD because we evaluated all pertinent information and determined an unsafe condition exists and is likely to exist or develop on other products of the same type design.

Differences Between This AD and the MCAI or Service Information

We have reviewed the MCAI and related service information and, in general, agree with their substance. But we might have found it necessary to use different words from those in the MCAI to ensure the AD is clear for U.S. operators and is enforceable. In making these changes, we do not intend to differ substantively from the information provided in the MCAI and related service information.

We might also have proposed different actions in this AD from those in the MCAI in order to follow FAA policies. Any such differences are highlighted in a NOTE within the proposed AD.

Costs of Compliance

Based on the service information, we estimate that this proposed AD would affect about 13 products of U.S. registry. We also estimate that it would take about 4 work-hours per product to comply with the basic requirements of this proposed AD. The average labor rate is $80 per work-hour. Required parts would cost about $3,750 per product. Where the service information lists required parts costs that are covered under warranty, we have assumed that there will be no charge for these costs. As we do not control warranty coverage for affected parties, some parties may incur costs higher than estimated here. Based on these figures, we estimate the cost of the proposed AD on U.S. operators to be $52,910, or $4,070 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.

We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD and placed it 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:

Fokker Services B.V.: Docket No. FAA-2007-28923; Directorate Identifier 2007-NM-133-AD.

Comments Due Date

(a) We must receive comments by September 17, 2007.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Fokker Model F.28 Mark 0070 and 0100 airplanes; certificated in any category; all serial numbers, if equipped with Messier-Dowty main landing gear (MLG) units.

Subject

(d) Air Transport Association (ATA) of America Code 32: Landing gear.

Reason

(e) The mandatory continuing airworthiness information (MCAI) states:

Over the years, several Fokker 100 (F28 Mark 0100) operators reported that a MLG (main landing gear) wheel fell off during regular operation of the aircraft. These incidents occurred due to a missing spacer, which had inadvertently not been installed during a previous wheel change. Omitting the installation of the wheel spacer allows the wheel to move sideways along the axle, which subsequently leads to bearing failure, followed by loss of the wheel. Investigation by Fokker and Messier-Dowty has shown that two separate items, the spacer and the axle nut, can be replaced by a single axle-nut/spacer assembly, to prevent the possibility of omitting the spacer. In 1995, Messier-Dowty issued Service Bulletin (SB) F100-32-72 to make sure that the operator does not assemble the axle nut without the spacer. Fokker subsequently issued SB F100-32-096 to notify Fokker 100 operators of the (optional) Messier-Dowty SB's existence. At a later stage, Fokker revised the SB to the status of “recommended”. In spite of all this attention to the spacer problem, wheel losses are still being reported due to missing wheel nut spacers. This condition, if not corrected, may lead to further wheel loss incidents, each of which could conceivably result in loss of control of the aircraft during the take-off run, landing rollout or taxiing operations. Since a potentially unsafe condition has been identified that may exist or develop on aircraft of the same type design, this Airworthiness Directive requires the replacement of the axle-nut and spacer with an integrated axle-nut/spacer assembly. In addition, the Aircraft Maintenance Manual (AMM) and Illustrated Parts Catalogue (IPC) must be amended to prevent reversal to a separate axle-nut and spacer installation during a subsequent wheel change.

Actions and Compliance

(f) Unless already done, do the following actions.

(1) Within 12 months after the effective date of this AD, replace each MLG wheel axle-nut and spacer with an integrated axle-nut/spacer assembly in accordance with the Accomplishment Instructions of Messier-Dowty Service Bulletin F100-32-72, Revision 1, dated March 5, 2007.

Note 1:

Fokker 70/100 Service Letter 102, Revision 1, dated February 12, 1998; and Fokker Service Bulletin SBF100-32-096, Revision 2, dated April 29, 2005, also pertain to this subject.

(2) As of 12 months after the effective date of this AD, no person may install an axle nut having part number (P/N) 201072670 or alternate P/N 201072765, or any spacer having P/N 201072699, on any airplane. Only axle nut subassemblies having P/N 201251273 or P/N 201650216 may be installed.

(3) Actions accomplished before the effective date of this AD in accordance with Messier-Dowty Service Bulletin F100-32-72, dated January 25, 1995, are considered acceptable for compliance with the corresponding action specified in this AD.

FAA AD Differences

Note:

This AD differs from the MCAI and/or service information as follows:

(1) The MCAI requires revising the AMM and IPC. As these documents are not FAA-approved, we do not require these revisions. Therefore, this AD requires compliance with paragraph (f)(2) of this AD, which accomplishes the intent of revising the AMM and IPC.

Other FAA AD Provisions

(g) The following provisions also apply to this AD:

(1) Alternative Methods of Compliance (AMOCs): The Manager, International Branch, ANM-116, Transport Airplane Directorate, 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: Tom Rodriguez, Aerospace Engineer, International Branch, ANM-116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone]. 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.

(2) Airworthy Product: For any requirement in this AD to obtain corrective actions from a manufacturer or other source, use these actions if they are FAA-approved. Corrective actions are considered FAA-approved if they are approved by the State of Design Authority (or their delegated agent). You are required to assure the product is airworthy before it is returned to service.

(3) Reporting Requirements: For any reporting requirement in this AD, under the provisions of the Paperwork Reduction Act, the Office of Management and Budget (OMB) has approved the information collection requirements and has assigned OMB Control Number 2120-0056.

Related Information

(h) Refer to MCAI Dutch Airworthiness Directive NL-2005-008, dated June 30, 2005, Fokker 70/100 Service Letter 102, Revision 1, dated February 12, 1998, and Messier-Dowty Service Bulletin F100-32-72, Revision 1, dated March 5, 2007, for related information.

Issued in Renton, Washington, on July 30, 2007.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.