AD 97-11-02 R1

This amendment revises an existing airworthiness directive (AD), applicable to certain British Aerospace (Jetstream) Model 4101 airplanes, that currently requires an inspection to determine the thickness of the intercostal that attaches the third crew member seat to the floor structure in the flight compartment, and replacement, if necessary. That action was prompted by a report from the manufacturer indicating that intercostals have been installed that are not of sufficient thickness (and consequent strength) to support the third crew member seat during emergency landing dynamic conditions. The actions specified by that AD are intended to prevent the failure of this intercostal during an emergency landing, which could consequently result in injury to the flight crew. This amendment revises the applicability of the existing AD by removing several airplanes.

Final rule

97-11-02 R1 BRITISH AEROSPACE REGIONAL AIRCRAFT [Formerly Jetstream Aircraft Limited; British Aerospace (Commercial Aircraft) Limited]: Amendment 39-10276. Docket 97-NM-127-AD. Revises AD 97-11-02, Amendment 39-10031.
Applicability: Jetstream Model 4101 airplanes, as listed in Jetstream Alert Service Bulletin J41-A53-030, Revision 2, dated February 14, 1997; 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 (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 failure during emergency landing dynamic conditions of the intercostal that attaches the third crew member seat ("third crew seat") to the floor structure in the flight compartment, which could consequently result in injury to the flight crew, accomplish the following:

(a) Within 30 days after July 2, 1997 (the effective date of AD 97-11-02, amendment 39-10031), inspect the intercostal in the floor structure that supports the third crew seat in the flight compartment to determine the thickness of this part, in accordance with Part 1 of Jetstream Alert Service Bulletin J41-A53-030, dated January 19, 1996, Revision 1, dated August 8, 1996, or Revision 2, dated February 14, 1997.

(b) If the thickness of the intercostal is 0.064 inch, no furtheraction is required by this AD.

(c) If the thickness of the intercostal is 0.048 inch, accomplish the actions specified in either paragraph (c)(1) or (c)(2) of this AD.

(1) Prior to further flight, replace the intercostal with a new part manufactured from material having the correct thickness, in accordance with Jetstream Alert Service Bulletin J41-A53- 030, dated January 19, 1996, Revision 1, dated August 8, 1996, or Revision 2, dated February 14, 1997. After replacement, no further action is required by this AD. Or

(2) Prior to further flight, install a placard, in accordance with Jetstream Alert Service Bulletin J41-A53-030, dated January 19, 1996, Revision 1, dated August 8, 1996, or Revision 2, dated February 14, 1997, to prohibit use of the third crew seat when the total weight of carry-on items stored in the forward right stowage area is more than 100 pounds. Within 6 months after installation of the placard, replace the intercostal with a new part manufactured from material having the correct thickness, in accordance with any of the service bulletins. After installation of the new intercostal, the placard may be removed.

(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 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.

(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 to a location where the requirements of this AD can be accomplished.

(f) The actions shall be done in accordance with Jetstream Alert Service Bulletin J41-A53-030, dated January 19, 1996; Jetstream Alert Service Bulletin J41-A53-030, Revision 1, dated August 8, 1996; and Jetstream Alert Service Bulletin J41-A53-030, Revision 2, dated February 14, 1997.

(1) The incorporation by reference of Jetstream Alert Service Bulletin J41-A53-030, Revision 1, dated August 8, 1996; and Jetstream Alert Service Bulletin J41-A53-030, Revision 2, dated February 14, 1997; is approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. These Jetstream alert service bulletins contain the following list of effective pages:

Service Bulletin
Referenced and Date

Page Number
Revision Level
Shown on Page
Date
Shown on Page

J41-A53-030,
Revision 1,
August 8, 1996
1, 3

2, 4-7
1

Original
August 8, 1996

January 19, 1996

J41-A53-030,
Revision 2,
February 14, 1997
1, 3

2,4-7
2

Original
February 14, 1997

January 19, 1996

(2) The incorporation by reference of Jetstream Alert Service Bulletin J41-53-030, dated January 19, 1996, was approved previously by the Director of the Federal Register as of July 2, 1997 (62 FR 28795, May 28, 1997).

(3) 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.

NOTE 3: The subject of this AD is addressed in British airworthiness directive 006-01-96.

(g) This amendment becomes effective on February 17, 1998.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by revising AD 97-11-02, amendment 39-10031 (62 FR 28795, May 28, 1997), which is applicable to certain British Aerospace (Jetstream) Model 4101 airplanes, was published in the Federal Register on October 14, 1997 (62 FR 53272). The action proposed to continue to require a one-time inspection of the intercostal of the third crew member seat to the floor structure in the flight compartment to determine the thickness of this part, and replacement with a new intercostal of the correct thickness, if necessary. The action also proposed to limit the applicability of the existing AD by removing several airplanes. Comments

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

Both commenters support the proposed rule. Conclusion

After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed. Cost Impact

Since this AD merely deletes airplanes from the applicability of the existing AD, it adds no additional costs, and requires no additional work to be performed by affected operators. The current costs associated with this AD are reiterated in their entirety (as follows) for the convenience of affected operators:

The FAA estimates that 14 Jetstream Model 4101 airplanes of U.S. registry will be affected by this AD, that it will take approximately 1 work hour per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $840, or $60 per airplane.

The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the requirements of this ADaction, 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 finalevaluation 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 39-10031 (62 FR 28795, May 28, 1997), and by adding a new airworthiness directive (AD), amendment 39-10276, to read as follows: