AD 94-12-01

This amendment adopts a new airworthiness directive (AD), applicable to certain Fokker Model F27 series airplanes, that requires replacement of certain bolts that are currently installed in various flight critical components of the airplane. This amendment is prompted by reports of incidents involving corrosion and fatigue cracking in transport category airplanes that are approaching or have exceeded their economic design goal; these incidents have jeopardized the airworthiness of the affected airplanes. The actions specified by this AD are intended to prevent reduced structural integrity of various flight critical components of the airplane.

Final rule

94-12-01 FOKKER: Amendment 39-8928. Docket 93-NM-201-AD.
Applicability: Model F27 series airplanes, having serial numbers 10102 through 10612, inclusive; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent reduced structural integrity of various flight critical components of the airplane, accomplish the following:

(a) Within 3 years after the effective date of this AD, remove AN bolts that are currently installed in the flight controls, control surfaces, fuel control installations, engine mount and nacelle brace installations, and engine control installations, and replace them with NAS 1303/1320 bolts, in accordance with Fokker Service Bulletin F27/51-10, Revision 2, dated June 12, 1993, as amended by Service Bulletin Change Notification F27/51 - 10REV2/01, dated October 1, 1993.

(b) As of the effective date of this AD, no person shall install on any airplane any AN bolt having a part number that is listed in Fokker Service Bulletin F27/51-10, Revision 2, dated June 12, 1993, as amended by Service Bulletin Change Notification F27/51 - 10REV2/01, dated October 1, 1993, in any of the flight critical components identified in the service bulletin.

(c) 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, Standardization Branch, ANM-113, 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, Standardization Branch, ANM-113.

NOTE: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113.

(d) 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.

(e) The removal and replacement shall be done in accordance with Fokker Service Bulletin F27/51-10, Revision 2, dated June 12, 1993, as amended by Fokker Service Bulletin Change Notification F27/51 - 10REV2/01, dated October 1, 1993. Fokker Service Bulletin F27/51-10, Revision 2, dated June 12, 1993, contains the following list of effective pages:

Page Number
Revision Level
Shown on Page
Date
Shown on Page
1-5
2
June 12, 1993
6, 7
1
August 7, 1991
8-15
Original
August 16, 1961

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 Aircraft USA, Inc., 1199 North Fairfax Street, Alexandria, Virginia 22314. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of theFederal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(f) This amendment becomes effective on July 20, 1994.

A proposal to amend part 39 of the Federal Aviation Regulations to include an airworthiness directive (AD) that is applicable to certain Fokker F27 series airplanes was published in the Federal Register on February 9, 1994 (59 FR 5968). That action proposed to require replacement of AN bolts that are currently installed in various flight critical components of the airplane with NAS bolts.

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. The FAA has determined that air safety and the public interest require the adoption of the rule as proposed.

The FAA estimates that 39 airplanes of U.S. registry will be affected by this AD, that it will take approximately 250 work hours per airplane to accomplish the required actions, and that the average labor rate is $55 per work hour. Required partswill cost approximately $690 per airplane. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $563,160, or $14,440 per airplane.

The FAA recognizes that the modification requires a large number of work hours to accomplish. However, the 3-year compliance time specified in paragraph (a) of this AD should allow ample time for the replacement of AN bolts to be accomplished coincidentally with scheduled major airplane inspection and maintenance activities, thereby minimizing the costs associated with special airplane scheduling.

The total cost impact figure discussed above is 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.

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 byreference, Safety.

Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends 14 CFR part 39 of the Federal Aviation Regulations as follows:

PART 39 - AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89.

39.13 - [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive: