Airworthiness Directives; Saab Model SAAB 2000 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 2000 series airplanes. This proposal would require replacing the dual shuttle valve in the number 2 hydraulic system with a new improved valve; and, for certain airplanes, modifying the hydraulic system. This action is necessary to prevent failure of the dual shuttle valve in the number 2 hydraulic system, with reduced maximum elevator rate on the left side, which could result in pilot induced pitch oscillation, and consequent reduced controllability of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by October 20, 2003.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-365-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 (425) 227-1232. Comments may also be sent via the Internet using the following address: 9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must contain “Docket No. 2001-NM-365-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, Linköping, Sweden. 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 (425) 227-1175; fax (425) 227-1149.

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-365-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-365-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 2000 series airplanes. The LFV advises that fatigue testing revealed that the body of the dual shuttle valve in the number 2 hydraulic system may crack at the pressure side. This cracking may cause the loss of hydraulic pressure to the left inboard elevator, resulting in reduced maximum elevator rate on the failed side, for which the flight crew could attempt to compensate. This condition, if not corrected, could result in pilot induced pitch oscillation, and consequent reduced controllability of the airplane.

Explanation of Relevant Service Information

Saab has issued Service Bulletin 2000-29-020, dated August 14, 2001. The service bulletin describes procedures for replacing the dual shuttle valve in the number 2 hydraulic system with a new, improved valve on airplanes that have had Modification 5952 implemented.

Saab has also issued Service Bulletin 2000-29-010, Revision 02, dated August 14, 2001, which describes procedures for the completion of Modification 5952. That modification presents changes to let the integrated hydraulic package (IHP) operate in a standby mode. The service bulletin also introduces a dual shuttle valve in the IHP system, changes the position of the check valve, replaces the IHP, installs new tubing and connections, and introduces a new filter.

The LFV classified Saab Service Bulletin 2000-29-020 as mandatory and issued Swedish airworthiness directive 1-164, dated August 17, 2001, to ensure the continued airworthiness of these airplanes in Sweden. The LFV approved Saab Service Bulletin 2000-29-010, Revision 02.

Accomplishment of the actions specified in the service bulletins is intended to adequately address the identified unsafe condition.

FAA's Conclusions

This airplane model is manufactured in Sweden and is type certificated for operation in the United States under the provisions of § 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 service bulletins described previously, except as discussed below.

Differences Between the Proposed Rule, Swedish Airworthiness Directive, and the Service Bulletins

Where this proposed AD would require completion of Saab Service Bulletin 2000-29-020, dated August 14, 2001, and Saab Service Bulletin 2000-29-010, Revision 02, dated August 14, 2001, the LFV has specifically mandated only Service Bulletin 2000-29-020. However, that service bulletin specifies that Service Bulletin 2000-29-010 must be done before Service Bulletin 2000-29-020, so Service Bulletin 2000-29-010 may be implicitly required by the LFV.

As a result, the proposed compliance time differs from that of the Swedish airworthiness directive. This proposed AD would require that the valve be replaced per Service Bulletin 2000-29-020 within 15,000 flight hours after the effective date of the AD if Service Bulletin 2000-29-010 has been incorporated. If Service Bulletin 2000-29-010 has not been incorporated, this proposed AD would require its accomplishment within 90 days, and replacement of the valve within 15,000 flight hours thereafter. However, the Swedish airworthiness directive does not specifically mandate incorporation of Service Bulletin 2000-29-010 and therefore does not provide a compliance time for that action.

Saab Service Bulletin 2000-29-010, Revision 02, dated August 14, 2001, also recommends accomplishment of the actions in Saab Service Bulletins 2000-29-008, 2000-29-009, 2000-29-011, and 2000-29-013. However, this proposed AD would not require those additional actions.

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. Because we have now included this material in part 39, only the office authorized to approve AMOCs is identified in each individual AD.

Change to Labor Rate Estimate

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 3 airplanes of U.S. registry would be affected by this proposed AD.

The proposed replacement would take approximately 4 work hours per airplane, at an average labor rate of $65 per work hour. Parts would be provided to the operator at no charge. Based on these figures, the cost impact of the proposed replacement on U.S. operators is estimated to be $780, or $260 per airplane.

The proposed modification, if required, would take approximately 60 work hours per airplane at an average labor rate of $65 per work hour. Parts would be provided to the operator at no charge. Based on these figures, the cost impact of the proposed modification is estimated to be $3,900 per airplane.

The cost impact figures discussed above are 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.