AD 94-04-06

This amendment adopts a new airworthiness directive (AD), applicable to certain Fokker Model F28 Mark 0100 series airplanes, that requires replacement of the existing ground/flight microswitches located in the main landing gear with improved microswitches, and installation of an anti-skid system ON/OFF switch in the flight compartment. This amendment is prompted by an incident involving loss of braking, which was caused by mechanical ground/flight microswitches that froze while in the flight position. The actions specified by this AD are intended to prevent loss of braking below 40 miles per hour, when the anti-skid system is activated.

Final rule

94-04-06 FOKKER: Amendment 39-8824. Docket 93-NM-107-AD.
Applicability: Model F28 Mark 0100 series airplanes; serial numbers 11244 through 11265 inclusive, 11268 through 11283 inclusive, 11286, 11289, 11291, 11293, 11295, 11297, 11300, and 11303; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent loss of braking below 40 miles per hour, when the anti-skid system is activated, accomplish the following:

(a) For all airplanes: Within 3 months after the effective date of this AD, replace the existing Dowty Electronics left- and right-hand ground/flight microswitches, part number 620602801, issue 1, with new, improved microswitches, part number 620602801, issue 2, at the main landing gear (MLG) downlock, temperature sensor, and anti-skid harness positions, in accordance with Fokker Service Bulletin SBF100-32-060, dated October 20, 1992.

(b) For airplanes having serial numbers 11244 through 11265 inclusive, 11268 through 11275 inclusive, 11277, and 11279: Within 12 months after the effective date of this AD, install an anti-skid system ON/OFF switch in the flight compartment in accordance with Fokker Service Bulletin SBF100-32-060, dated October 20, 1992.

(c) As of the effective date of this AD, no person shall install a Dowty Electronics left- and/or right-hand ground/flight microswitch, part number 620602801, issue 1, on any airplane.

(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, 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.

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

(f) The replacement and installation shall be done in accordance with Fokker Service Bulletin SBF100-32-060, dated October 20, 1992. 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.

(g) This amendment becomes effective on March 21, 1994.

A proposal to amend part 39 of the Federal Aviation Regulations to include an airworthiness directive (AD) that is applicable to certain Fokker Model F28 Mark 0100 series airplanes was published in the Federal Register on September 1, 1993 (58 FR 46139). That action proposed to require replacement of the existing left- and right-hand ground/flight microswitches with new, improved microswitches at the MLG downlock, temperature sensor, and anti-skid harness positions. The proposed rule would also require installation of an anti-skid system ON/OFF switch in the flight compartment, for certain airplanes.

Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.

One commenter supports the proposed rule.

The Air Transport Association (ATA) of America, on behalf of one of its members, requests withdrawal of the proposal. The commenter notes that the proposed replacement and installation has already been accomplished on all 14 airplanes affected by this proposal in the U.S.-registered fleet. Therefore, the commenter does not believe that an AD is necessary. The commenter also asserts that issuance of the proposal would only add to an administrative paperwork burden. The FAA does not agree. Issuance of this AD is necessary to ensure accomplishment of the requirements on any affected airplane currently of foreign registry that is purchased by a U.S. operator and placed on the U.S. register in the future. The FAA has determined that issuance of this AD should only result in a minor administrative burden, since the required actions have already been accomplished.

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

The FAA estimates that 14 airplanes of U.S. registry will be affected by this AD. The FAA has been advised that all 14 affected airplanes have been modified in accordance with the requirements of this AD. Therefore, currently, this AD action imposes no additional economic burden on any U.S. operator.

However, should an unmodified airplane be imported and placed on the U.S. Register in the future, it will take approximately 113 work hours per airplane to accomplish the proposed actions, at an average labor rate of $55 per work hour. Required parts would cost approximately $1,800 per airplane. Based on these figures, the total cost impact of the AD is estimated to be $8,015 per airplane.

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 14 CFR part 39of 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: