AD 95-02-19

This amendment adopts a new airworthiness directive (AD) that applies to Jetstream Aircraft Limited (JAL) HP137 Mk1, Jetstream series 200, and Jetstream Models 3101 and 3201 airplanes. This action requires repetitively inspecting the left and right pilot windscreens for poly vinyl butyrate (PVB) interlayer cracks, and replacing any windscreen that has a crack exceeding certain limits. Several reports of PVB interlayer cracking of pilot windscreens on the affected airplanes prompted this action. The actions specified by this AD are intended to prevent such windscreen cracking, which, if not detected and corrected, could result in decompression injuries.

Final rule

95-02-19 JETSTREAM AIRCRAFT LIMITED: Amendment 39-9137; Docket No. 94-CE- 13-AD.
Applicability: HP137 Mk1, Jetstream Series 200, and Jetstream Models 3101 and 3201 airplanes (all serial numbers), certificated in any category.

Compliance: Required within the next 300 hours time-in-service (TIS) after the effective date of this AD, unless already accomplished, and thereafter as indicated.

To prevent pilot windscreen poly vinyl butyrate (PVB) interlayer cracking, which, if not detected and corrected, could result in decompression injuries, accomplish the following:

(a) Visually inspect the left and right windscreens for PVB interlayer cracks in accordance with the ACCOMPLISHMENT INSTRUCTIONS section of Jetstream Service Bulletin (SB) 56-JA 92043, Revision No. 1, dated December 16, 1993.

(1) If any crack is found that is within the limits specified in Pilkington Aerospace SB No. 037-56-1001, Issue Date: October 21, 1992, Revision 1: March 31, 1993, reinspectwithin the next 300 hours TIS, and replace or reinspect the windscreen thereafter as applicable.

(2) If any crack is found that exceeds the limits specified in Pilkington Aerospace SB No. 037-56-1001, Issue Date: October 21, 1992, Revision 1: March 31, 1993, prior to further flight, replace the windscreen with a new windscreen and reinspect within the next 2,400 hours TIS, and replace or reinspect the windscreen thereafter as applicable.

(3) If no cracks are found, reinspect the windscreen within the next 2,400 hours TIS, and replace or reinspect the windscreen thereafter as applicable.

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

(d) The inspections required by this AD shall be done in accordance with Jetstream Service Bulletin 56-JA 920843, Revision No. 1, dated December 16, 1993. 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 March 10, 1995.

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 HP137 Mk1, Jetstream series 200, and Jetstream Models 3101 and 3201 airplanes was published in the Federal Register on October 14, 1994 (59 FR 52102). The action proposed to require repetitively inspecting the left and right pilot windscreens for PVB interlayer cracks, and replacing any windscreen that has a crack exceeding certain limits. The proposed action would be accomplished in accordance with Jetstream Service Bulletin 56-JA 920843, Revision 1, dated December 16, 1993.

Interested persons have been afforded an opportunity to participate in the making of this amendment. One comment was received in favor of the proposed rule and no comments were received on the FAA's determination of the cost to the public.

After careful review of all available information, 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 nor add any additional burden upon the public than was already proposed.

The FAA estimates that 160 airplanes in the U.S. registry will be affected by this AD, that it will take approximately 1 workhour per airplane to accomplish the required action, and that the average labor rate is approximately $55 an hour. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $8,800. This figure does not take into account any possible window replacements or repetitive inspections. The FAA has no way of determining how many windscreens may have PVB interlayer cracks that exceed the limitations and would require replacement, or the number of repetitive inspections each owner/operator may incur.

The regulations adopted herein will not have substantial direct effects on theStates, 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 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89.

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