AD 98-21-02

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Fokker Model F27 Mark 100, 200, 300, 400, 500, 600, and 700 Rough Field Version (RFV) series airplanes, that currently requires inspection of the main landing gear (MLG) legs to determine if parts are missing or damaged, and modification, if necessary; and periodic measurements of the extension of each MLG shock absorber sliding member. That AD also provides for the accomplishment of a certain modification as optional terminating action for the periodic measurements. This amendment requires accomplishment of the previously optional terminating action, and revises the applicability of the existing AD to add an airplane model. 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 loss of the MLG sliding member, which could result in reduced structural integrity of the MLG.

Final rule

98-21-02 FOKKER SERVICES B.V.: Amendment 39-10810. Docket 98-NM-92-AD. Supersedes AD 93-22-02, Amendment 39-8727.

Applicability: Model F27 Mark 050, 100, 200, 300, 400, 500, 600, and 700 Rough Field Version (RFV) series airplanes, equipped with Dowty Aerospace MLG Legs, part and serial numbers as listed in Dowty Aerospace Landing Gear Service Bulletin 32-77W, Revision 4, dated February 3, 1993, or Dowty Aerospace Landing Gear Service Bulletin F50-32-27, Revision 4, dated December 18, 1992; 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 (g) ofthis 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 loss of the MLG sliding member, which could result in reduced structural integrity of the MLG, accomplish the following:

RESTATEMENT OF REQUIREMENTS OF AD 93-22-02:
(a) For Model F27 Mark 100, 200, 300, 400, 500, 600, and 700 RFV series airplanes, equipped with Dowty Aerospace MLG, part numbers 200563001, 200679001, 200679002, 200679003, or 200679004: Within 30 days after December 16, 1993 (the effective date of AD 93-22-02, amendment 39-8727), inspect the MLG legs to confirm the correct installation of the sliding member out-stop installation, in accordance with Fokker Service Bulletin F27-32-165, Revision 1, dated April 28, 1993, and paragraph 2.C. ("Part A Procedure") of Dowty Aerospace Landing Gear Service Bulletin 32-81W, Revision 2, dated February 3, 1993. If any parts are determined to be missing or damaged, prior to further flight, modify the MLG assembly, in accordance with Dowty Aerospace Landing Gear Service Bulletin 32-77W, Revision 4, dated February 3, 1993.

(b) For Model F27 Mark 100, 200, 300, 400, 500, 600, and 700 RFV series airplanes, equipped with Dowty Aerospace MLG, part numbers 200563001, 200679001, 200679002, 200679003, or 200679004: Within 30 days after December 16, 1993, measure and record the extension of the MLG sliding member when the landing gear is fully extended, in accordance with paragraph 2.D. ("Part B Procedure") of Dowty Aerospace Landing Gear Service Bulletin 32-81W, Revision 2, dated February 3, 1993.

(1) If the extension dimension exceeds 410.2 mm (16.15 inches), prior to further flight, modify the MLG assembly in accordance with Dowty Aerospace Landing Gear Service Bulletin 32-77W, Revision 4, dated February 3, 1993.

(2) If the extension dimension is equal to or less than 410.2 mm (16.15 inches), repeat the measurement thereafter at intervals not to exceed 500 flight cycles.

(3) If the extension dimension increases by more than 1.0 mm (0.40 inch) above the initially recorded dimension during any measurement required by this paragraph, prior to further flight, inspect the MLG in accordance with paragraph (a) of this AD.

NEW REQUIREMENTS OF THIS AD:
(c) For airplanes other than those identified in paragraph (a) of this AD: Within 30 days after the effective date of this AD, inspect the MLG legs to confirm the correct installation of the sliding member out-stop installation, in accordance with paragraph 2.C. ("Part A Procedure") of Messier-Dowty Service Bulletin F50-32-48, Revision 4, dated June 21, 1995. If any parts are determined to be missing or damaged, prior to further flight, modify the MLG assembly, inaccordance with Dowty Aerospace Landing Gear Service Bulletin F50-32-27, Revision 4, dated December 18, 1992.

(d) For airplanes other than those identified in paragraph (a) of this AD: Within 30 days after the effective date of this AD, measure and record the extension of the MLG sliding member when the landing gear is fully extended, in accordance with paragraph 2.D. ("Part B Procedure") of Messier-Dowty Service Bulletin F50-32-48, Revision 4, dated June 21, 1995.

(1) If the extension dimension exceeds 410.2 mm (16.15 inches), prior to further flight, modify the MLG assembly in accordance with Dowty Aerospace Landing Gear Service Bulletin F50-32-27, Revision 4, dated December 18, 1992.

(2) If the extension dimension is equal to or less than 410.2 mm (16.15 inches), repeat the measurement thereafter at intervals not to exceed 500 flight cycles.

(3) If the extension dimension increases by more than 1.0 mm (0.40 inch) above the initially recorded dimension duringany measurement required by this paragraph, prior to further flight, inspect the MLG in accordance with paragraph (c) of this AD.

(e) For all airplanes: Within 5,000 flight cycles or 24 months after the effective date of this AD, whichever occurs earlier, modify the MLG piston rod assembly, in accordance with Dowty Aerospace Landing Gear Service Bulletin 32-77W, Revision 4, dated February 3, 1993 (for Model F27 Mark 100, 200, 300, 400, 500, 600, and 700 series airplanes), or Dowty Aerospace Landing Gear Service Bulletin F50-32-27, Revision 4, dated December 18, 1992 (for Model F27 Mark 050 series airplanes), as applicable. Accomplishment of this modification constitutes terminating action for the repetitive actions required by this AD.

(f) As of the effective date of this AD, no person shall install on any airplane, an MLG piston rod assembly, unless it has been modified in accordance with Dowty Aerospace Landing Gear Service Bulletin 32-77W, Revision 4, dated February 3, 1993 (for Model F27 Mark 100, 200, 300, 400, 500, 600, and 700 series airplanes), or Dowty Aerospace Landing Gear Service Bulletin F50-32-27, Revision 4, dated December 18, 1992 (for Model F27 Mark 050 series airplanes), as applicable.

(g) 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.

(h) 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.

(i) The actions shall be done in accordance with Fokker Service Bulletin F27-32-165, Revision 1, dated April 28, 1993; Dowty Aerospace Landing Gear Service Bulletin 32-81W, Revision 2, dated February 3, 1993; Dowty Aerospace Landing Gear Service Bulletin 32-77W, Revision 4, dated February 3, 1993; Messier-Dowty Service Bulletin F50-32-48, Revision 4, dated June 21, 1995; and Dowty Aerospace Landing Gear Service Bulletin F50-32-27, Revision 4, dated December 18, 1992, which contains the specified list of effective pages:

Page Number
Shown on Page
Revision Level
Shown on Page
Date
Shown on Page
1, 5, 6
4
December 18, 1992
2-4, 7-9
3
September 29, 1992

(1) The incorporation by reference of Dowty Aerospace Landing Gear Service Bulletin F50-32-27, Revision 4, dated December 18, 1992; and Messier-Dowty Service Bulletin F50-32-48, Revision 4, dated June 21, 1995; is approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.

(2) The incorporation by reference of Fokker Service Bulletin F27-32-165, Revision 1, dated April 28, 1993; Dowty Aerospace Landing Gear Service Bulletin 32-81W, Revision 2, dated February 3, 1993; and Dowty Aerospace Landing Gear Service Bulletin 32-77W, Revision 4, dated February 3, 1993; was approved previously by the Director of the Federal Register as of December 16, 1993 (58 FR 60370, November 16, 1993).

(3) 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 1996-159/2 (A), dated July 31, 1997.

(j) This amendment becomes effective on November 10, 1998.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 93-22-02, amendment 39-8727 (58 FR 60370, November 16, 1993), which is applicable to certain Fokker Model F27 Mark 100, 200, 300, 400, 500, 600, and 700 Rough Field Version (RFV) series airplanes, was published in the Federal Register on August 13, 1998 (63 FR 43342). The action proposed to continue to require inspection of the main landing gear (MLG) legs to determine if parts are missing or damaged, and modification, if necessary; and periodic measurements of the extension of each MLG shock absorber sliding member. That action also provides for the accomplishment of a certain modification as optional terminating action for the periodic measurements. The action also proposed to require accomplishment of the previously optional terminating action, and to revise the applicability of the existing AD to add an airplane model.

Comments
Interested personshave 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
There are 34 Fokker Model F27 Mark 100, 200, 300, 400, 500, 600, and 700 RFV series airplanes, and no Fokker Model F27 Mark 050 series airplanes, of U.S. registry that will be affected by this AD.

The actions that are currently required by AD 93-22-02, and retained in this AD, will take approximately 3 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the currently required inspections on U.S. operators is estimated to be $6,120, or $180 per airplane, per inspection cycle.

The new modification that is required in this AD action will take approximately 2 work hoursper airplane to accomplish, at an average labor rate of $60 per work hour. Required parts will be supplied by the manufacturer at no cost to the operators. Based on these figures, the cost impact of the modification required by this AD on U.S. operators is estimated to be $4,080, or $120 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 removing amendment 39-8727 (58 FR 60370, November 16, 1993), and by adding a new airworthiness directive (AD), amendment 39-10810, to read as follows: