03-24846. Airworthiness Directives; BAE Systems (Operations) Limited (Jetstream) Model 4101 Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all BAE Systems (Operations) Limited (Jetstream) Model 4101 airplanes. This proposal would require 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:

Comments must be received by October 31, 2003.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-270-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 2001-NM-270-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 or 2000 or ASCII text.

The service information referenced in the proposed rule may be obtained from British Aerospace Regional Aircraft American Support, 13850 Mclearen Road, Herndon, Virginia 20171. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

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 [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received.

Submit comments using the following format:

• Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
• For each issue, state what specific change to the proposed AD is being requested.
• Include justification (e.g., reasons or data) for each request.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2001-NM-270-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-270-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom, notified the FAA that an unsafe condition may exist on all BAE Systems (Operations) Limited (Jetstream) Model 4101 airplanes. The CAA advises that during an inspection done in accordance with Jetstream Service Bulletin J41-A53-023, referenced in AD 98-24-01, amendment 39-10888 (63 FR 63975, November 18, 1998), which addresses the diaphragms in the nose cone structure, operators found damage in diaphragms 14153005-177 and -178. When those diaphragms were removed to allow for replacement, fatigue cracking was found in the primary structure of the nose of the airplane at the forward avionics bay (fuselage stations 4 to 11). Such fatigue cracking, if not detected and corrected in a timely manner, could result in reduced structural integrity of the airplane.

Explanation of Relevant Service Information

The manufacturer has issued Jetstream Service Bulletin J41-53-047, Revision 1, dated July 19, 2002, which describes procedures for various inspections of the fuselage nose structure between stations 4 and 11, and corrective actions, if necessary, as follows:

• Repetitive detailed visual inspections of (1) the forward avionics bay doors for damage, and repair of damage within certain limits; (2) the cho-shield conductive coating for cracking, flaking, wearing, and any uneven surface; restoration of the coating, if necessary; and surface resistance tests of the coating; (3) the forward and rear faces of the station 4 bulkhead and the attached parts for damage, and repair of damage within certain limits; (4) all the aircraft structure between the rear face of the station 4 bulkhead and station 8 for damage, and repair of damage within certain limits; and (5) all the aircraft structure between stations 8 and 11 for damage, and repair of damage within certain limits.
• Repetitive detailed visual inspections for cracks and corrosion of the surround structures for the avionics bay doors including the aft vertical closing frames, frame 8, upper gutters, corner gussets, and lower gutters.
• Repetitive radiographic and eddy current inspections for cracks and corrosion of the avionics bay doors apertures including the door frames, gutters and corner gussets.
• Repetitive radiographic and eddy current inspections of the high intensity radiated field (HIRF) seal at the avionics bay doors apertures for damage (including mechanical damage, corrosion, and exposure of the ferrex wire in the bulb of the seal), and replacement of the seal, if necessary; and surface resistance tests of the HIRF seal.

Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition. The CAA classified this service bulletin as mandatory and issued British airworthiness directive 001-06-2001 to ensure the continued airworthiness of these airplanes in the United Kingdom.

FAA's Conclusions

This airplane model is manufactured in the United Kingdom and is type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the CAA has kept the FAA informed of the situation described above. The FAA has examined the findings of the CAA, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, the proposed AD would require accomplishment of the actions specified in the service bulletin described previously, except as discussed below.

Differences Between the Service Bulletin and This Proposed AD

Operators should note that, although the Accomplishment Instructions of the referenced service bulletin describe procedures for submitting reports of inspection findings, this proposed AD would not require those actions. The FAA does not need this information from operators.

Although the service bulletin describes a detailed visual inspection, this proposed AD would require a detailed inspection.

Also, the service bulletin specifies that operators may contact the manufacturer for disposition of repairs, this proposal would require operators to repair per a method approved by either the FAA or the CAA (or its delegated agent). In light of the type of repair that would be required to address the unsafe condition, and consistent with existing bilateral airworthiness agreements, we have determined that, for this proposed AD, a repair approved by either the FAA or the CAA (or its delegated agent) would be acceptable for compliance with this proposed AD.

The Planning Information in Jetstream Service Bulletin J41-53-047, Revision 1, dated July 19, 2002, states that operators may remove the HIRF seal and do a detailed visual inspection of the avionics bay door surround structure under the HIRF seal, or do a radiographic and eddy current inspection of the avionics bay door surround structure. The Accomplishment Instructions of the service bulletin do not specify that operators may choose which type of inspection to perform. This proposed AD clarifies that operators may choose to do either a detailed inspection or radiographic and eddy current inspections.

Changes to 14 CFR Part 39/Effect on the Proposed AD

On July 10, 2002, the FAA issued a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs the FAA's airworthiness directives system. The regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance (AMOCs). Because we have now included this material in part 39, only the office authorized to approve AMOCs is identified in each individual AD.

Explanation of Labor Rate Increase

We have reviewed the figures we have used over the past several years to calculate AD costs to operators. To account for various inflationary costs in the airline industry, we find it necessary to increase the labor rate used in these calculations from $60 per work hour to $65 per work hour. The cost impact information, below, reflects this increase in the specified hourly labor rate.

Cost Impact

The FAA estimates that 57 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 50 work hours per airplane to accomplish the proposed inspection, and that the average labor rate is $65 per work hour. Based on these figures, the cost impact of the proposed 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 proposed 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 proposed herein would 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 proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this proposed regulation (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, 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 draft regulatory 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
• Safety

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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 adding the following new airworthiness directive:

BAE Systems (Operations) Limited (Formerly British Aerospace Regional Aircraft): 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:

(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 Jetstream 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.

(c) If any discrepancy is found during any inspection required by this AD, before further flight, repair per Jetstream 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.

Note 2:

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

Issued in Renton, Washington, on September 24, 2003.

Ali Bahrami,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.