AD 96-24-01

This amendment adopts a new airworthiness directive (AD), applicable to all Fokker Model F27 Mark 100, 200, 300, 400, 500, 600, and 700 series airplanes, that requires replacement of certain rudder horn assemblies with a new assembly. For certain airplanes, the amendment also requires replacement of certain rudder control rods with a new rod. This amendment is prompted by reports of cracked rudder horns and a cracked rudder control rod, caused by impact overload. The actions specified by this AD are intended to prevent such an overload and consequent cracking of the subject parts, which could result in reduced structural integrity of the rudder horn assembly or loss of rudder control; this condition could lead to reduced controllability of the airplane.

Final rule

96-24-01 FOKKER: Amendment 39-9827. Docket 96-NM-80-AD.
Applicability: All Model F27 Mark 100, 200, 300, 400, 500, 600, and 700 series airplanes, certificated in any category.

NOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise 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 an impact overload and consequent cracking of the subject parts, which could result in reduced structural integrity of the rudder horn assembly or loss of rudder control, and, consequently, lead to reduced controllability of the airplane, accomplish the following:

(a) Within 18 months after the effective date of this AD, accomplish paragraphs (a)(1) and (a)(2) of this AD, as applicable, in accordance with Fokker Service Bulletin F27/27-131, Revision 1, dated June 15, 1994.

(1) For all airplanes: Replace the rudder horn assembly, having part number (P/N) 3401-042-901 or 3401-042-401, with a new rudder horn assembly, having P/N F3402-070-407, in accordance with Part 1 of the Accomplishment Instructions of the service bulletin.

(2) For airplanes having serial numbers 10102, and 10105 through 10165 inclusive: Replace the rudder control rod, having P/N 5233-018-xxx, with a new rudder control rod, having P/N F8507-052-403, in accordance with Part 2 ofthe Accomplishment Instructions of the service bulletin.

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

(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 replacements shall be done in accordance with Fokker Service Bulletin F27/27- 131,Revision 1, dated June 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 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 the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(e) This amendment becomes effective on December 27, 1996.

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 all Fokker Model F27 Mark 100, 200, 300, 400, 500, 600, and 700 series airplanes was published in the Federal Register on August 27, 1996 (61 FR 44004). That action proposed to require replacement of certain rudder horn assemblies with a new rudder horn assembly. For certain airplanes, that action also proposed to require replacement of certain rudder control rods with a new rudder control rod.

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 Fokker Model F27 Mark 100, 200, 300, 400, 500, 600, and 700 series airplanes of U.S. registry will be affected by this AD. It will take approximately 7 work hours per airplane to accomplish the replacement of the rudder horn assembly, at an average labor rate of $60 per work hour. Required parts will cost approximately $2,656 per airplane. Based on these figures, the cost impact of the replacement of the rudder horn assembly required by this AD on U.S. operators is estimated to be $101,490, or $2,985 per airplane.

There currently are no Fokker Model F27 Mark 100, 200, 300, 400, 500, 600, or 700 series airplanes on the U.S. Register that will require the replacement of the rudder control rod. The only airplanes that will require this replacement currently are operated by non-U.S. operators under foreign registry; therefore, they are not directly affected by this AD action. However, the FAA considers that inclusion of that requirement in this rule is necessary to ensure that the unsafe condition is addressed in the eventthat any of these airplanes are imported and placed on the U.S. Register in the future.

Should any of those airplanes (having serial numbers 10102, and 10105 through 10165, inclusive) be imported and placed on the U.S. Register in the future, it will take approximately 5 work hours per airplane to accomplish the replacement of the rudder control rod, at an average labor rate of $60 per work hour. Required parts will cost approximately $635 per airplane. Based on these figures, the cost impact of the replacement of the rudder control rod required by this AD on U.S. operators is estimated to be $935 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 relationshipbetween 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: