E8-14969. Airworthiness Directives; Fokker Model F.28 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:

Service experience has shown that heavy MLG (main landing gear) shimmy vibration can occur due to faulty/empty dampers or due to excessive free play in the T/L (torque link) apex joint. In several cases this shimmy vibration resulted in a MLG main fitting failure * * * finally resulting in a collapse of the MLG causing extensive damage to the wingtip, aileron and flaps. * * *

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 August 1, 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 W12-40, 1200 New Jersey Avenue, SE., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.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-2008-0676; Directorate Identifier 2007-NM-280-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://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

The Civil Aviation Authority—The Netherlands (CAA-NL), which is the aviation authority for the Netherlands, has issued Dutch Airworthiness Directive NL-2007-001, dated February 26, 2007 (referred to after this as “the MCAI”), to correct an unsafe condition for the specified products. The MCAI states:

Service experience has shown that heavy MLG (main landing gear) shimmy vibration can occur due to faulty/empty dampers or due to excessive free play in the T/L (torque link) apex joint. In several cases this shimmy vibration resulted in a MLG main fitting failure. In those cases where only the upper torque link attachment lug failed the damage to the aircraft was limited. In all other cases the MLG main fitting cracked, finally resulting in a collapse of the MLG causing extensive damage to the wingtip, aileron and flaps. To prevent the collapse of the MLG, Messier-Dowty has designed an upper torque link fuse pin with a static strength lower than the demonstrated strength of the MLG main fitting. In case of a heavy shimmy vibration the upper torque link fuse pin will fail before the main fitting. Therefore the installation of an upper torque link fuse pin will protect the LH and RH (left- and right-hand) MLG main fitting against extreme shimmy loads and thus against a MLG main fitting failure and a MLG collapse. Since an unsafe condition has been identified that may exist or develop on aircraft of the same type design this Airworthiness Directive requires the modification of the MLG by replacing the upper torque link pin with a new fuse pin.

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

Relevant Service Information

Fokker Services B.V. has issued Service Bulletin SBF100-32-148, Revision 1, dated February 26, 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 2 products of U.S. registry. We also estimate that it would take about 15 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 $0 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 $2,400, or $1,200 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-2008-0676; Directorate Identifier 2007-NM-280-AD.

Comments Due Date

(a) We must receive comments by August 1, 2008.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Fokker Model F.28 Mark 0070 and F.28 Mark 0100, serial numbers 11244 thru 11585, certificated in any category, equipped with Messier-Dowty main landing gears.

Subject

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

Reason

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

Service experience has shown that heavy MLG (main landing gear) shimmy vibration can occur due to faulty/empty dampers or due to excessive free play in the T/L (torque link) apex joint. In several cases this shimmy vibration resulted in a MLG main fitting failure. In those cases where only the upper torque link attachment lug failed the damage to the aircraft was limited. In all other cases the MLG main fitting cracked, finally resulting in a collapse of the MLG causing extensive damage to the wingtip, aileron and flaps. To prevent the collapse of the MLG, Messier-Dowty has designed an upper torque link fuse pin with a static strength lower than the demonstrated strength of the MLG main fitting. In case of a heavy shimmy vibration the upper torque link fuse pin will fail before the main fitting. Therefore the installation of an upper torque link fuse pin will protect the LH and RH (left- and right-hand) MLG main fitting against extreme shimmy loads and thus against a MLG main fitting failure and a MLG collapse. Since an unsafe condition has been identified that may exist or develop on aircraft of the same type design this Airworthiness Directive requires the modification of the MLG by replacing the upper torque link pin with a new fuse pin.

Actions and Compliance

(f) Within the applicable compliance time specified in paragraphs (f)(1) and (f)(2) of this AD, unless already done, do the following actions.

(1) For Messier-Dowty MLG in a pre-mod Messier-Dowty Service Bulletin F100-32-050 configuration: Within 12 months after the effective date of this AD, replace the upper torque link pin with a new fuse pin in accordance with the Accomplishment Instructions of Fokker Service Bulletin SBF100-32-148, Revision 1, dated February 26, 2007.

(2) For Messier-Dowty MLG in a post-mod Messier-Dowty Service Bulletin F100-32-050 configuration: Within 30 months after the effective date of this AD, replace the upper torque link pin with a new fuse pin in accordance with the Accomplishment Instructions of Fokker Service Bulletin SBF100-32-148, Revision 1, dated February 26, 2007.

FAA AD Differences

Note:

This AD differs from the MCAI and/or service information as follows: The MCAI references the original version of the service bulletin or a later approved version. The original version of the service bulletin specifies to use an incorrect part number. This AD refers to Revision 1 of the service bulletin.

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-2007-001, dated February 26, 2007, and Fokker Service Bulletin SBF100-32-148, Revision 1, dated February 26, 2007, for related information.

Issued in Renton, Washington, on June 24, 2008.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.