Airworthiness Directives; BAE Systems (Operations) Limited (Jetstream) Model 4101 Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule.

SUMMARY:

This amendment adopts a new airworthiness directive (AD), applicable to all BAE Systems (Operations) Limited (Jetstream) Model 4101 airplanes, that requires various inspections of the fuselage nose structure between stations 4 and 11, and corrective actions if necessary. This action is necessary to detect and correct fatigue cracking in the primary structure of the nose of the airplane at the forward avionics bay (fuselage stations 4 to 11), which could result in reduced structural integrity of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Effective August 31, 2004.

The incorporation by reference of certain publications, as listed in the regulations, is approved by the Director of the Federal Register as of August 31, 2004.

ADDRESSES:

The service information referenced in this AD may be obtained from British Aerospace Regional Aircraft American Support. This information may be examined at the Federal Aviation Administration (FAA), Transport Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call (202) 741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

FOR FURTHER INFORMATION CONTACT:

Todd Thompson, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-1175; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION:

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 BAE Systems (Operations) Limited (Jetstream) Model 4101 airplanes was published in the Federal Register on October 1, 2003 (68 FR 56596). That action proposed to require various inspections of the fuselage nose structure between stations 4 and 11, and corrective actions if necessary.

Comments

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

Request To Withdraw Proposed AD

The commenter, an operator, states that the proposed AD is an unnecessary burden to operators. The commenter suggests that instead of the FAA issuing an AD, the maintenance review board (MRB) report should be revised to include the actions required by the proposed AD. The commenter states that it currently performs numerous inspections for cracking on its fleet of Jetstream Model 4101 airplanes using procedures specified in the commenter's maintenance programs. The commenter notes that BAE Systems (Operations) Limited Service Bulletin J41-53-047, Revision 1, dated July 19, 2002, specifies that when the inspections and procedures in the service bulletin are published in the MRB report and the maintenance planning document (MPD), the inspections and procedures will be deleted from the service bulletin and the MRB report will become the published source document. The commenter also notes that another operator, with a fleet of 27 Jetstream Model 4101 airplanes, did the inspections specified in the service bulletin and did not find any cracking. Compliance with the proposed AD would require the commenter to bring 25 airplanes “off-line” to access and inspect the areas specified in the proposed AD. The commenter states that if the inspection procedures were added to the MRB report through a revision, an operator could merge these inspections into its established maintenance program so the inspections coincide with the operator's heavy maintenance program, which would reduce the operational impact.

The FAA infers that the commenter is requesting that the AD be withdrawn. We do not agree. The procedures specified in operators' MRB reports are not mandatory. Therefore, we must issue an AD to ensure that the identified unsafe condition is properly addressed. We acknowledge that some operators may currently have maintenance programs that address the unsafe condition. If a program is adequate, an operator would be in a position to request approval for an alternative method of compliance with the AD (i.e., to follow the operator's current program rather than revise it to comply with the AD). Our obligation to issue the AD and address an unsafe condition remains; the rule must apply to everyone to ensure that all affected airplanes are covered, regardless of who operates them. Furthermore, the airworthiness authority for the state of design issued an airworthiness directive mandating the same actions required by this AD. This AD has not been changed regarding this issue.

Request To Revise Cost Impact Section

The commenter notes that the figure in the Cost Impact section of the proposed AD does not include incidental costs, such as the time required to gain access and close up an airplane. The commenter states that these costs are not incidental, and that the majority of time required to perform the various inspections is spent accessing the areas to be inspected.

We infer that the commenter is requesting that the Cost Impact section of the proposed AD be revised. We do not agree. As stated in the proposed AD, “the figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD.” The specific actions required by the AD are various inspections of the fuselage nose structure between stations 4 and 11. We expect that most operators will be able to do the actions required by this AD during scheduled maintenance. We attempt to set compliance times that generally coincide with operators' maintenance schedules. However, because operators' schedules vary substantially, we cannot accommodate every operator's optimal scheduling in each AD. The time necessary for gaining access to and closing the inspection area is incidental. This AD has not been changed regarding this issue.

The commenter also objects to the FAA's assumption that “no operator would accomplish those actions in the future if this AD were not adopted.” The commenter states that it performs numerous inspections for cracking in accordance with its maintenance program.

The commenter appears to have misunderstood the context of the quoted statement: “The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted.” The purpose of the Cost Impact section of the NPRM is to estimate the costs of compliance with the proposed AD. As stated, for this purpose, the FAA assumes that all operators taking the required actions are doing so only because the AD requires it. We recognize that in most cases this assumption is incorrect, and that the resulting costs attributed to the AD are exaggerated. But we do not have access to data that would enable us to accurately determine on what percentage of affected airplanes the actions would be done in the absence of the AD. This AD has not been changed regarding this issue.

Explanation of Changes to This AD

We have included the headers “Inspections” and “Corrective Actions” in the body of this AD. These headers were inadvertently omitted from the proposed AD. We also changed the citations for the appropriate source of service information from Jetstream Service Bulletin J41-53-047, Revision 1, dated July 19, 2002, to BAE Systems (Operations) Limited Service Bulletin J41-53-047, Revision 1, dated July 19, 2002, to comply with the Office of the Federal Register's guidelines for material incorporated by reference. We have determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

Conclusion

After careful review of the available data, including the comments noted above, we have determined that air safety and the public interest require the adoption of the rule with the changes previously described.

Cost Impact

The FAA estimates that 57 airplanes of U.S. registry will be affected by this AD, that it will take approximately 50 work hours per airplane to accomplish the required actions, and that the average labor rate is $65 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $185,250, or $3,250 per airplane, per inspection cycle.

The cost impact figure discussed above is 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. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

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.

2. Section 39.13 is amended by adding the following new airworthiness directive:

2004-15-06 BAE Systems (Operations) Limited (Formerly British Aerospace Regional Aircraft): Amendment 39-13740. Docket 2001-NM-270-AD.

Applicability: All Model Jetstream 4101 airplanes, certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To detect and correct fatigue cracking in the primary structure of the nose of the airplane at the forward avionics bay (fuselage stations 4 to 11), which could result in reduced structural integrity of the airplane, accomplish the following:

Inspections

(a) Perform detailed, radiographic, and eddy current inspections of the fuselage nose structure between stations 4 and 11 for discrepancies (including cracking, corrosion, and exposed wiring), per the Accomplishment Instructions of BAE Systems (Operations) Limited Service Bulletin J41-53-047, Revision 1, dated July 19, 2002, except that reporting results of inspection findings is not required by this AD. Do the inspections at the later of the times specified in paragraphs (a)(1) and (a)(2) of this AD. Repeat the inspections thereafter at intervals not to exceed 6,000 landings.

(1) Prior to the accumulation of 10,000 total landings, but not before the accumulation of 7,000 total landings.

(2) Within 3,000 landings after the effective date of this AD, or at the next 8-year environmental (corrosion) inspection, whichever occurs first.

Note 1:

For the purposes of this AD, a detailed inspection is defined as: “An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required.”

(b) For the inspections of the surround structure for the avionics bay doors, operators may either remove the high intensity radiated field (HIRF) seal and do a detailed inspection, or do radiographic and eddy current inspections with the HIRF seal in place.

Corrective Actions

(c) If any discrepancy is found during any inspection required by this AD, before further flight, repair per BAE Systems (Operations) Limited Service Bulletin J41-53-047, Revision 1, dated July 19, 2002. Where the service bulletin specifies contacting the manufacturer for disposition of repairs, before further flight, repair per a method approved by the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate; or the Civil Aviation Authority (or its delegated agent).

Alternative Methods of Compliance

(d) In accordance with 14 CFR 39.19, the Manager, International Branch, ANM-116, FAA, is authorized to approve alternative methods of compliance for this AD.

Incorporation by Reference

(e) Unless otherwise specified in this AD, the actions shall be done in accordance with BAE Systems (Operations) Limited Service Bulletin J41-53-047, Revision 1, dated July 19, 2002. 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 British Aerospace Regional Aircraft American Support, 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 National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call (202) 741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

Note 2:

The subject of this AD is addressed in British airworthiness directive 001-06-2001.

Effective Date

(f) This amendment becomes effective on August 31, 2004.