AD 98-01-02

This amendment adopts a new airworthiness directive (AD), applicable to all Fokker Model F28 Mark 1000, 2000, 3000, and 4000 series airplanes, that requires a one-time visual inspection of the rear cargo door and luggage auxiliary structure for corrosion, repetitive borescope inspections of the rear cargo door, and removal and repair of any corrosion found during the inspections. This amendment also requires the drilling of drain holes and application of a corrosion preventive and sealing compound inside the rear cargo door, and modification of the rear cargo door to aid in future routine borescope inspections. This amendment is prompted by reports of corrosion being found in the affected areas on several of the affected airplanes. The actions specified by this AD are intended to prevent such corrosion, which could result in structural failure of the cargo door and loss of the door during flight, and consequent rapid decompression, aerodynamic instability, and/or damage toother fuselage structures.

Final rule

98-01-02 FOKKER: Amendment 39-10266. Docket 96-NM-174-AD.
Applicability: All F28 Mark 1000, 2000, 3000, and 4000 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 (c) 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.

Toprevent corrosion in the rear cargo door, which could result in structural failure of the cargo door and loss of the door during flight, and consequent rapid decompression, aerodynamic instability, and/or damage to other fuselage structures, accomplish the following:

(a) Within 2 years after the effective date of this AD, accomplish the requirements of paragraphs (a)(1), (a)(2), and (a)(3) of this AD, in accordance with Fokker Service Bulletin F28-52-111, dated March 12, 1994.

(1) Perform a one-time visual inspection of the rear cargo door and luggage auxiliary structure for corrosion. If any corrosion is found, prior to further flight, remove and repair it.

(2) Drill drain holes and apply a corrosion preventive and sealing compound inside the rear cargo door.

(3) Modify the rear cargo door to provide inspection holes for borescope inspections.

(b) Within 6,000 hours time-in-service (TIS) or 3 years after accomplishing the visual inspection required by paragraph (a)(1) of this AD, whichever occurs first; and thereafter at intervals not to exceed 6,000 hours TIS or 3 years, whichever occurs first: Perform a borescope inspection of the rear cargo door for corrosion in accordance with Chapter 52-30-2 of the F28 Maintenance Manual. If any corrosion is detected, prior to further flight, remove and repair it in accordance with the maintenance manual.

(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, 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.

(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) Except as provided by paragraph (b) of this AD, the actions shall be done in accordance with Fokker Service Bulletin F28-52-111, dated March 12, 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 No. 1995-126 (A), dated November 30, 1995.

(f) This amendment becomes effective on February 4, 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 all Fokker Model F28 Mark 1000, 2000, 3000, and 4000 series airplanes was published in the Federal Register on May 30, 1997 (62 FR 29308). That action proposed to require a one-time visual inspection of the rear cargo door and luggage auxiliary structure for corrosion, repetitive borescope inspections of the rear cargo door, and removal and repair of any corrosion found during the inspections. That action also required the drilling of drain holes and application of a corrosion preventive and sealing compound inside the rear cargo door, and modification of the rear cargo door to aid in future routine borescope inspections. Comments

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

The commenter indicates that the proposed rule would have limited impact on its operations since it intends to retire the remainder of its fleet of affected airplanes. Conclusion

After careful review of the available data, including the comment noted above, 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 37 airplanes of U.S. registry will be affected by this AD. It will take approximately 13 work hours per airplane to accomplish the required initial inspection, at an average labor rate of $60 per work hour. The FAA has no way of determining how many repetitive inspections the owners/operators will incur over the life of the affected airplanes. Based on these figures, the cost impact of the initial inspection required by this AD on U.S. operators is estimated to be $28,860, or $780 per airplane.

It will take approximately 27 work hours per airplane to accomplish the required modification, 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 $59,940, or $1,620 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: