AD 2000-04-04

This amendment adopts a new airworthiness directive (AD), applicable to all Fokker Model F.28 Mark 0070 and 0100 series airplanes, that requires a measurement of the resistance of the electrical connectors of the auxiliary power unit (APU) to detect a short circuit; an inspection to determine if the grommets or shrink sleeves are present; and modification, if necessary. 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 detect and prevent a short circuit of a fire extinguisher electrical system due to a lack of shrink sleeves or grommets, and consequent disabling of the affected fire extinguisher system.

Final rule

2000-04-04 FOKKER SERVICES B.V.: Amendment 39-11586. Docket 99-NM-325-AD.

Applicability: All Model F.28 Mark 0070 and 0100 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 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 detect and prevent a short circuit of a fire extinguisher electrical system due to a lack of shrink sleeves or grommets, and consequent disabling of the affected fire extinguisher system, accomplish the following:

Inspection and Modification, If Necessary
(a) Within 12 months after the effective date of this AD, perform a measurement of the resistance of the electrical lines on the auxiliary power unit (APU) and engine fire extinguisher bottles to detect a short circuit, in accordance with Part A of the Accomplishment Instructions of Fokker Service Bulletin SBF100-26-015, dated August 15, 1999.

(1) If no short circuit is detected, at the next scheduled weight check of the fire extinguishing bottle, or within 2 years after the inspection required by paragraph (a) of this AD, whichever occurs first, perform a general visual inspection to determine if the grommets or shrink sleeves are present and installed properly. If any grommet or shrink sleeve is missing or not installed properly, prior to further flight, perform the modification of the connectors, in accordance with Part B of the Accomplishment Instructions of the service bulletin.

(2) If any short circuit is detected, prior to further flight, perform a general visual inspection to determine if the grommets or shrink sleeves are present and installed properly. If any grommet or shrink sleeve is missing or not installed properly, prior to further flight, perform the modification of the connectors, in accordance with Part B of the Accomplishment Instructions of the service bulletin.

NOTE 2: For the purposes of this AD, a general visual inspection is defined as "A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or drop-light, and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked."

Alternative Methods of Compliance
(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, 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 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116.

Special Flight Permits
(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.Incorporation by Reference
(d) The actions shall be done in accordance with of Fokker Service Bulletin SBF100-26-015, dated August 15, 1999. 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., P.O. Box 231, 2150 AE Nieuw-Vennep, 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 4: The subject of this AD is addressed in Dutch airworthiness directive 1999-110, dated August 31, 1999.

(e) This amendment becomes effective on March 30, 2000.

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 F.28 Mark 0070 and 0100 series airplanes was published in the Federal Register on December 6, 1999 (64 FR 68056). That action proposed to require a measurement of the resistance of the electrical connectors of the auxiliary power unit (APU) to detect a short circuit; an inspection to determine if the grommets or shrink sleeves are present; and modification, if necessary.

Comments
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 123 airplanes of U.S. registry willbe affected by this AD. It will take approximately 2 work hours per airplane to accomplish the measurement specified in Part A of the referenced service bulletin, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of this measurement required by this AD on U.S. operators is estimated to be $14,760, or $120 per airplane. It will take approximately 1 work hour per airplane to accomplish the inspection specified in Part B of the referenced service bulletin, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of this inspection required by this AD on U.S. operators is estimated to be $7,380, or $60 per airplane. Should an operator be required to accomplish the modification specified in Part B of the referenced service bulletin, it will take approximately 2 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 modification required by thisAD on U.S. operators is estimated to be $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 a substantial direct effect 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, it is determined that this final rule does not have federalism implications under Executive Order 13132.

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: