AD 98-26-15

This amendment supersedes an existing airworthiness directive (AD), applicable to certain British Aerospace (Jetstream) Model 4101 airplanes, that currently requires repetitive detailed visual inspections to detect cracks in the shear cleats of the roller guide structural support of the passenger door, and replacement of any cracked shear cleat with a new shear cleat. That AD also provides for an optional terminating modification that constitutes terminating action for the repetitive inspections. This amendment mandates accomplishment of the previously optional terminating modification. This amendment is prompted by reports indicating that fatigue cracking was detected in the roller guide shear cleats of the passenger door. The actions specified by this AD are intended to prevent such fatigue-related cracking, which could result in structural failure or loss of the passenger door, and consequent rapid depressurization of the airplane during flight.

Final rule

98-26-15 BRITISH AEROSPACE REGIONAL AIRCRAFT [Formerly Jetstream Aircraft Limited; British Aerospace (Commercial Aircraft) Limited]: Amendment 39-10958. Docket 97-NM-195-AD. Supersedes AD 97-16-01, Amendment 39-10090.
Applicability: Jetstream Model 4101 airplanes, constructor's numbers 41004 through 41099 inclusive; 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 (d) 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 prevent fatigue-related cracking in the shear cleats of the roller guide structural support of the passenger door, which could result in structural failure or loss of the passenger door, and consequent rapid depressurization of the airplane during flight, accomplish the following: RESTATEMENT OF REQUIREMENTS OF AD 97-16-01:

(a) Except as provided by paragraph (b) of this AD: Prior to the accumulation of 6,000 landings, or within 60 days after August 12, 1997 (the effective date of AD 97-16-01, amendment 39-10090), whichever occurs later, perform a detailed visual inspection to detect cracks of the shear cleats of the roller guide structural support of the passenger door, in accordance with Part 1 of the Accomplishment Instructions of Jetstream Alert Service Bulletin J41-A52-043, Revision 2, dated May 6, 1997. Repeat the detailed visual inspection, as specified in Part 2 of the Accomplishment Instructions of the alert service bulletin, thereafter at intervals not to exceed 1,500 landings.

NOTE 2: Accomplishment of the initial detailed visual inspection prior to August 12, 1997, in accordance with Jetstream Alert Service Bulletin J41-52-043, dated March 14, 1997, or Revision 1, dated April 11, 1997, is considered acceptable for compliance with the initial inspection required by paragraph (a) of this AD.

(1) If one cracked shear cleat is detected, and the crack is greater than 0.50 inches, prior to further flight, replace the cracked shear cleat with a new shear cleat in accordance with the alert service bulletin.

(2) If one cracked shear cleat is detected, and the crack is less than or equal to 0.50 inches, within 170 landings following accomplishment of the inspection required by this paragraph, replace the cracked shear cleat with a new shear cleat in accordance withthe alert service bulletin.

(3) If more than one cracked shear cleat is detected, but no single crack is greater than 0.50 inches in length, prior to further flight, replace all cracked shear cleats with new shear cleats in accordance with the alert service bulletin.

(b) For airplanes on which all shear cleats have been replaced: Inspect as required by paragraph (a) of this AD, prior to the accumulation of 6,000 total landings on the highest time new shear cleat, or within 60 days after August 12, 1997, whichever occurs later. Repeat the detailed visual inspection thereafter at intervals not to exceed 1,500 landings. NEW REQUIREMENTS OF THIS AD:

(c) Modify the passenger door (Modification No. JM41576) at all four roller guide locations in accordance with Jetstream Service Bulletin J41-52-050, dated May 6, 1997, at the time specified in paragraph (c)(1) or (c)(2) of this AD, whichever occurs later. Accomplishment of this modification constitutes terminating action for the requirements of this AD.

(1) Within 4,000 landings or 2 years after accomplishment of the initial inspection required by paragraph (a) of this AD. Or

(2) Within 6 months after the effective date of this AD.

(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, 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.

(e) 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 toa location where the requirements of this AD can be accomplished.

(f) The actions shall be done in accordance with Jetstream Alert Service Bulletin J41-A52-043, Revision 2, dated May 6, 1997, and Jetstream Service Bulletin J41-52-050, dated May 6, 1997. This incorporation by reference was approved previously by the Director of the Federal Register as of August 12, 1997 (62 FR 40267, July 28, 1997). Copies may be obtained from AI(R) American Support, Inc., 13850 Mclearen Road, Herndon, Virginia 20171. 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 January 25, 1999.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 97-16-01, amendment 39-10090 (62 FR 40267, July 28, 1997), which is applicable to certain British Aerospace (Jetstream) Model 4101 airplanes, was published in the Federal Register on October 27, 1998 (63 FR 57266). The action proposed to require repetitive detailed visual inspections to detect cracks in the shear cleats of the roller guide structural support of the passenger door, and replacement of any cracked shear cleat with a new shear cleat. The action also proposed to mandate accomplishment of the previously optional terminating modification.

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 supports the proposed rule.
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
There are approximately 57 Jetstream Model 4101 airplanes of U.S. registry that will be affected by this AD.

The inspections that are currently required by AD 97-16-01, and retained in this AD, take approximately 3 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 currently required inspections on U.S. operators is estimated to be $10,260, or $180 per airplane, per inspection cycle.

The new modification that is required by this AD will take approximately 55 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts will cost approximately $2,460 per airplane. Based on these figures, the cost impact of the modification required by this AD on U.S. operators is estimated to be $328,320, or $5,760 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 removing amendment 39-10090 (62 FR 40267, July 28, 1997), and by adding a new airworthiness directive (AD), amendment 39-10958, to read as follows: