AD 98-09-07

This amendment adopts a new airworthiness directive (AD), applicable to certain Fokker Model F27 Mark 100, 200, 300, 400, 500, 600, and 700 series airplanes, that requires a modification of the lapjoint below the chine line at certain fuselage stations. 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 fatigue cracking in the lapjoint below the chine line at certain fuselage stations, which could result in reduced structural integrity of the fuselage.

Final rule

98-09-07 FOKKER: Amendment 39-10486. Docket 96-NM-186-AD.
Applicability: Model F27 Mark 100, 200, 300, 400, 500, 600, and 700 series airplanes, serial numbers 10102 through 10375 inclusive, that are operated or have been operated at a maximum cabin pressure differential of 5.5 pounds per square inch (psi); 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 (d) 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 notbeen eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent fatigue cracking in the lapjoint below the chine line at certain fuselage stations, which could result in reduced structural integrity of the fuselage, accomplish the following:

(a) For airplanes on which Fokker Service Bulletin F27/53-68, dated July 4, 1966, or Revision 1, dated July 19, 1967, has not been accomplished: Prior to the accumulation of 32,000 total flight cycles, or within 2 years after the effective date of this AD, whichever occurs later, modify the lapjoint below the chine line between fuselage station 1400 and station 5050, in accordance with Part 1 of the Accomplishment Instructions of Fokker Service Bulletin F27/53-116, dated April 15, 1994. Accomplishment of this modification and accomplishment of the requirements of paragraph (b) of this AD constitute terminating action for the repetitive inspection requirements of items 53-30-02 and 53-30-03 of the Fokker Model F27 Structural Inspection Program (SIP), as required by AD 96-13-07, amendment 39-9675.

(b) For airplanes on which Fokker Service Bulletin F27/53-85, dated February 16, 1970, has not been accomplished: Prior to the accumulation of 32,000 total flight cycles, or within 2 years after the effective date of this AD, whichever occurs later, modify the lapjoint below the chine line between fuselage station 5050 and station 12975, in accordance with Part 2 of the Accomplishment Instructions of Fokker Service Bulletin F27/53-116, dated April 15, 1994. Accomplishment of this modification and accomplishment of the requirements of paragraph (a) of this AD constitute terminating action for the repetitive inspection requirements of items 53-30-02 and 53-30-03 of the Fokker Model F27 SIP, as required by AD 96-13-07.

(c) For airplanes on which Fokker Service Bulletin F27/53-85, dated February 16, 1970, has not been accomplished: Prior to the accumulation of 56,000 total flight cycles, or within 2 years after the effective date of this AD, whichever occurs later, modify the lapjoint below the chine line between fuselage station 12975 and station 16660, in accordance with Part 3 of the Accomplishment Instructions of Fokker Service Bulletin F27/53-116, dated April 15, 1994. Accomplishment of this modification constitutes terminating action for the repetitive inspection requirements of item 53-30-04 of the Fokker Model F27 SIP, as required by AD 96-13-07.

(d) 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.

(e) 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.

(f) The modifications shall be done in accordance with Fokker Service Bulletin F27/53-116, dated April 15, 1994. 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 BLA 94-092 (A), dated May 25, 1994.

(g) This amendment becomes effective on May 29, 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 F27 Mark 100, 200, 300, 400, 500, 600, and 700 series airplanes was published in the Federal Register on February 12, 1998 (63 FR 7078). That action proposed to require a modification of the lapjoint below the chine line at certain fuselage stations.

Comments
Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were submitted in response to the proposal or the FAA's determination of the cost to the public.

Conclusion
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 34 airplanes of U.S. registry will be affected by this AD.

It will take approximately 140 work hours per airplane to accomplish the required modification(specified as Part 1 in the referenced service bulletin), at an average labor rate of $60 per work hour. The cost of required parts will be nominal. Based on these figures, the cost impact of this modification required by this AD on U.S. operators is estimated to be $8,400 per airplane.

It will take approximately 300 work hours per airplane to accomplish the modification (specified as Part 2 in the referenced service bulletin), at an average labor rate of $60 per work hour. The cost of required parts will be nominal. Based on these figures, the cost impact of this modification required by this AD on U.S. operators is estimated to be $18,000 per airplane.

It will take approximately 210 work hours per airplane to accomplish the modification (specified as Part 3 in the referenced service bulletin), at an average labor rate of $60 per work hour. The cost of required parts will be nominal. Based on these figures, the cost impact of this modification required by this AD on U.S. operators is estimated to be $12,600 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: