AD 98-18-25

This amendment adopts a new airworthiness directive (AD), applicable to certain Fokker Model F28 Mark 1000, 2000, 3000, and 4000 series airplanes, that requires replacement of certain hinges on the forward, center, and aft cargo doors with improved hinges. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent failure of the cargo door hinges caused by stress corrosion or fatigue cracks, which could result in decompression of the airplane, and possible in-flight separation of the cargo door.

Final rule

98-18-25 FOKKER: Amendment 39-10741. Docket 97-NM-290-AD.

Applicability: Model F28 Mark 1000, 2000, 3000, and 4000 series airplanes; serial numbers 11003 through 11241 inclusive, 11991, and 11992; certificated in any category.

NOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (b) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent failure of the cargo door hinges caused by stress corrosion and/or fatigue cracks, which could result in decompression of the airplane, and possible in-flight separation of the cargo door; accomplish the following:

(a) Within 12 months after the effective date of this AD, replace the hinges on the forward, center, and aft belly cargo doors with improved hinges in accordance with Part 1, Part 2, and Part 3, as applicable, of the Accomplishment Instructions of Fokker Service Bulletin F28/52-110, dated April 7, 1993.

(b) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, International Branch, ANM-116.

NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116.

(c) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

(d) The actions shall be done in accordance with Fokker Service Bulletin F28/52-110, dated April 7, 1993. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Fokker Services B.V., Technical Support Department, P.O. Box 75047, 1117 ZN Schiphol Airport, the Netherlands. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

NOTE 3: The subject of this AD is addressed in Dutch airworthiness directive 93-055 (A), dated April 23, 1993.

(e) This amendment becomes effective on October 20, 1998.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain Fokker Model F28 Mark 1000, 2000, 3000, and 4000 series airplanes was published in the Federal Register on December 18, 1997 (62 FR 66317). That action proposed to require replacement of certain hinges on the forward, center, and aft cargo doors with improved hinges.

Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the single comment received. Request to Require Revision 12 of Structural Integrity Program (SIP)

One commenter suggests that the FAA revise AD 91-05-10 to require accomplishment of Revision 12 of the F28 Structural Integrity Program (SIP), rather than Revision 10. The commenter states that this change would be more effective than issuance of the proposed AD, which requires replacement of the cargo door hinges in accordance with Fokker Service Bulletin F28/52-110, dated April 7, 1993. The commenter notes that, as part of SIP Items 52-30-09 and 52-30-10, Revision 12 of the SIP specifies a reduction in the inspection intervals for the cargo door hinges, following their replacement as described in Fokker Service Bulletin F28/52-110. The commenter states that this reduction indicates that the hinges installed per the service bulletin are not significantly improved over those previously installed, and that the actions required by this proposed AD may be obsolete.

The FAA does not concur with the commenter's request to revise AD 91-05-10 and withdraw this proposed AD. The FAA first finds it necessary to clarify that AD 93-13-04, amendment 39-8617 (58 FR 38513, July 19, 1993), presently requires accomplishment of Revision 10 of the SIP, rather than AD 91-05-10, as suggested by the commenter. Based on information provided by the manufacturer, as well as further review of SIP Items 52-30-09 and 52-30-10, the FAA has determined that replacement of the cargo door hinges is necessary, as required by this AD, in order to adequately address the identified unsafe condition. The FAA may also consider separate rulemaking to require accomplishment of Revision 12 of the SIP; however, no change to this final rule is necessary.

Conclusion
After careful review of the available data, including the comment noted above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed.

Cost Impact
The FAA estimates that 37 airplanes of U.S. registry will be affected by this AD.

It will take approximately 62 work hours per airplane to replace the forward cargo door hinge, at an average labor rate of $60 per work hour. Required parts will cost approximately $5,740 per airplane. Based on these figures, the cost impact of this replacement required by this AD on U.S. operators is estimated to be $350,020, or $9,460per airplane.

It will take approximately 62 work hours per airplane to replace the center cargo door hinge, at an average labor rate of $60 per work hour. Required parts will cost approximately $5,650 per airplane. Based on these figures, the cost impact of this replacement required by this AD on U.S. operators is estimated to be $346,690, or $9,370 per airplane.

It will take approximately 46 work hours per airplane to replace the aft cargo door hinge, at an average labor rate of $60 per work hour. Required parts will cost approximately $6,470 per airplane. Based on these figures, the cost impact of this replacement required by this AD on U.S. operators is estimated to be $341,510, or $9,230 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. Regulatory Impact

The regulations adopted herein will not have substantial direct effects 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. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this action (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. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES."

List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (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. Section 39.13 is amended by adding the following new airworthiness directive: