AD 96-13-02

This amendment adopts a new airworthiness directive (AD) that applies to certain Jetstream Aircraft Limited (JAL) Jetstream Model 3201 airplanes. This action requires repetitively inspecting the spigot housing plate for cracks and corrosion at the wing/fuselage forward attachment sliding joint, replacing any cracked or corroded part, and eventually replacing the spigots and spigot housing plate with new parts of improved design. A crack in the spigot housing plate assembly found during fatigue testing of the affected airplanes prompted this action. The actions specified by this AD are intended to prevent structural failure of the wing/fuselage area caused by a cracked or corroded spigot housing assembly.

Final rule

96-13-02 JETSTREAM AIRCRAFT LIMITED: Amendment 39-9670; Docket No. 93-CE-34-AD.
Applicability: Jetstream Model 3201 airplanes (serial numbers 790 through 960), 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 (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 after the effective dateof this AD, unless already accomplished.

To prevent structural failure of the wing/fuselage area caused by a cracked spigot housing assembly, accomplish the following:

(a) Upon the accumulation of 7,200 hours time-in-service (TIS) or within the next 500 hours TIS after the effective date of this AD, whichever occurs later, inspect the spigot housing plate at the wing/fuselage forward attachment sliding joint for corrosion or cracks. Accomplish this inspection in accordance with Part 1 of the ACCOMPLISHMENT INSTRUCTIONS section of Jetstream Service Bulletin (SB) No. 57-JA 921144, Revision 1, dated April 19, 1994; or Jetstream SB No. 57-JA 921144, Original Issue, dated March 4, 1993.

(1) If any corrosion or cracks are found, prior to further flight, modify the spigot and spigot housing plate in accordance with either Part 2 or Part 3, as applicable, of the ACCOMPLISHMENT INSTRUCTIONS section of Jetstream SB No. 57-JA 921144, Revision 1, dated April 19, 1994.

(2)If no corrosion or cracks are found, within the next 3,000 hours TIS after the inspection required by paragraph (a) of this AD, modify the spigot and spigot housing plate in accordance with either Part 2 or Part 3, as applicable, of the ACCOMPLISHMENT INSTRUCTIONS section of Jetstream SB No. 57-JA 921144, Revision 1, dated April 19, 1994.

(3) Jetstream No. SB 57-JA 921144, Original Issue, dated March 4, 1993, is not applicable to this modification and shall not be utilized to accomplish either paragraph (a)(1) or (a)(2) of this AD.

(b) 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.

(c) An alternative method of compliance or adjustment of the initial or repetitive compliance times that provides an equivalent level of safety may be approved by the Manager, Brussels Aircraft Certification Office (ACO), Europe, Africa, Middle East office, FAA, c/o American Embassy, 1000 Brussels, Belgium. The request should be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Brussels ACO.

NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Brussels ACO.

(d) The inspection required by this AD shall be done in accordance with Jetstream Service Bulletin No. 57-JA 921144, Revision 1, dated April 19, 1994; or Jetstream Service Bulletin No. 57-JA 921144, Original Issue, dated March 4, 1993. The modification required by this AD shall be done in accordance with Jetstream Service Bulletin No. 57-JA 921144, Revision 1, dated April 19, 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 Jetstream Aircraft Limited, Manager Product Support, Prestwick Airport, Ayrshire, KA9 2RW Scotland; or Jetstream Aircraft Inc., Librarian, P.O. Box 16029, Dulles International Airport, Washington, DC, 20041-6029. Copies may be inspected at the FAA, Central Region, Office of the Assistant Chief Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(e) This amendment becomes effective on August 7, 1996.

Events Leading to the AD
A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to certain JAL Jetstream Model 3201 airplanes was published in the Federal Register on September 19, 1995 (60 FR 48429). The action proposed to require repetitively inspecting the spigot housing plate for cracks and corrosion at the wing/fuselage forward attachment sliding joint, replacing any cracked or corroded part, and eventually replacing the spigots and spigot housing plate with new parts of improved design. Accomplishment of the proposed actions would be in accordance with Jetstream Service Bulletin No. 57-JA 921144, Revision 1, dated April 19, 1994.

A crack in the spigot housing plate assembly found during fatigue testing of the affected airplanes prompted this action.

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were received on the proposed rule or the FAA's determination of the cost to the public.

After careful review of all available information related to the subject presented above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed except for minor editorial corrections. The FAA has determined that these minor corrections will not change the meaning of the AD and will not add any additional burden upon the public than was already proposed.

Cost Impact
The FAA estimates that 120 airplanes in the U.S. registry will be affected by this AD, that it will take approximately 23 workhours per airplane to accomplish the initial inspection and modification, and that the average labor rate is approximately $60 an hour. JAL will provide parts at no cost to the owner/operator. Based on these figures, the total cost impact of this AD on U.S. operators is estimated to be $165,600 or $1,380 per airplane. This figure is based on the assumption that noneof the affected airplanes have the required modification incorporated and does not take into account the cost of repetitive inspections. The FAA has no way of determining how many repetitive inspections each owner/operator will incur over the life of the airplane.

Jetstream Aircraft Limited has informed the FAA that parts have been distributed to equip approximately 30 airplanes (approximately 25 percent of the fleet in the U.S. registry). Assuming that each set of parts is installed on an affected Jetstream Model 3201 airplane, the cost impact of this AD upon U.S. operators is reduced $41,400 from $165,600 to $124,200.

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 copy of the final evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting 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 USC 106(g), 40113, 44701.

Section 39.13 - [AMENDED]
2. Section 39.13 is amended by adding a new airworthiness directive (AD) to read as follows: