04-8537. Airworthiness Directives; Saab Model SAAB SF340A and SAAB 340B Series 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 certain Saab Model SAAB SF340A and SAAB 340B series airplanes. This proposal would require replacement of the retract actuator bracket attachment bolt (RABAB) of the main landing gear (MLG) with a new RABAB, and reidentification of the MLG shock strut. This action is necessary to prevent failure of the RABAB, which could result in loosening of the actuator bracket and consequent failure of the MLG to retract, with considerable damage to other landing gear parts, including the MLG trunnion fitting. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by May 17, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2002-NM-182-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. 2002-NM-182-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 Saab Aircraft AB, SAAB Aircraft Product Support, S-581.88, Linkoping, Sweden. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT:

Rosanne Ryburn, 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 2002-NM-182-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. 2002-NM-182-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The Luftfartsverket (LFV), which is the airworthiness authority for Sweden, notified the FAA that an unsafe condition may exist on certain Saab Model SAAB SF340A and SAAB 340B series airplanes. The LFV advises that it has received reports of failures of the retract actuator bracket attachment bolt (RABAB) of the main landing gear (MLG) due to hydrogen embrittlement. This can be caused by failure to fully de-embrittle after electroplating the RABAB during manufacture. This condition, if not corrected, could result in loosening of the retract actuator bracket and consequent failure of the MLG to retract, with considerable damage to other landing gear parts, including the MLG trunnion fitting.

Explanation of Relevant Service Information

Saab has issued Service Bulletin 340-32-124, Revision 01, dated May 21, 2002, including as Attachments 1 and 2, APPH Ltd. Service Bulletins AIR83022-32-28 and AIR83064-32-08, both dated January 2002, which describes procedures for replacement of the RABAB with a new RABAB.

Saab has also issued Service Bulletin 340-32-125, dated April 29, 2002, including as Attachments 1 and 2, APPH Ltd. Service Bulletins AIR83022-32-29 and AIR83064-32-09, both dated April 2002, which describes procedures for reidentification of the MLG shock strut.

Accomplishment of the actions specified in the service bulletins is intended to adequately address the identified unsafe condition. The LFV classified these service bulletins as mandatory and issued Swedish airworthiness directive 1-173, dated March 4, 2002, to ensure the continued airworthiness of these airplanes in Sweden.

FAA's Conclusions

These airplane models are manufactured in Sweden and are 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 LFV has kept the FAA informed of the situation described above. The FAA has examined the findings of the LFV, 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 Saab service bulletins described previously.

Cost Impact

The FAA estimates that 281 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 7 work hours per airplane to accomplish the proposed actions, and that the average labor rate is $65 per work hour. Required parts would be supplied at no cost by the manufacturer. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $127,855, or $455 per airplane.

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:

Saab Aircraft AB: Docket 2002-NM-182-AD.

Applicability: Model SAAB SF340A series airplanes, serial numbers (S/Ns) 004 through 159 inclusive; and Model SAAB 340B series airplanes, S/Ns 160 through 459 inclusive; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent failure of the retract actuator bracket attachment bolt (RABAB) and in loosening of the retract actuator bracket and consequent failure of the MLG to retract, with considerable damage to other landing gear parts, including the MLG trunnion fitting, accomplish the following:

Replacement/Reidentification

(a) Within 12 months after the effective date of this AD, perform the actions specified in paragraphs (a)(1) and (a)(2) of this AD.

(1) Replace the existing RABAB with a new RABAB in accordance with the Accomplishment Instructions of Saab Service Bulletin 340-32-124, Revision 01, dated May 21, 2002, including Attachments 1 and 2, both dated January 2002.

Note 1:

APPH Ltd. Service Bulletins AIR83022-32-28 and AIR83064-32-08, both dated January 2002, comprising Attachments 1 and 2, are incorporated into Saab Service Bulletin 340-32-124 as additional sources of service information.

(2) Reidentify the MLG shock strut by replacing the nameplate with a new nameplate, or adding the Source Control Number to the existing nameplate; in accordance with the Accomplishment Instructions of Saab Service Bulletin 340-32-125, dated April 29, 2002, including Attachments 1 and 2, both dated April 2002.

Note 2:

APPH Ltd. Service Bulletins AIR83022-32-29 and AIR83064-32-09, both dated April 2002, comprising Attachments 1 and 2, are incorporated into Saab Service Bulletin 340-32-125 as additional sources of service information.

Parts Installation

(b) As of the effective date of this AD, no person may install a RABAB, part number (P/N) AIR83022-5 through -18, or P/N AIR83064 (any suffix), on any airplane.

Special Flight Permits

(c) Special flight permits are not allowed as specified in section 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199).

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 (AMOCs) for this AD.

Note 3:

The subject of this AD is addressed in Swedish airworthiness directive 1-173, dated March 4, 2002.

Issued in Renton, Washington, on April 6, 2004.

Kevin M. Mullin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.