AD 94-09-14

This amendment adopts a new airworthiness directive (AD), applicable to certain SAAB Model SAAB 340B series airplanes, that requires replacement of the existing actuator assembly on the motor operated fuel valve assembly with a new, improved actuator assembly. This amendment is prompted by electromagnetic interference (EMI) tests, which indicate that the actuator assemblies of certain fuel shut-off valves may fail to function after exposure to EMI, such as lightning or high intensity radiated fields. The actions specified by this AD are intended to prevent loss of function of the fuel shut-off valves, which could result in unchecked fuel leakage or fuel imbalance after fuel system failure.

Final rule

94-09-14 SAAB AIRCRAFT AB (formerly SAAB-SCANIA): Amendment 39-8903. Docket 93-NM-160-AD.
Applicability: Model SAAB 340B series airplanes; serial numbers 271, and 275 through 300, inclusive; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent loss of function of the fuel shut-off valves, which could result in unchecked fuel leakage or fuel imbalance after fuel system failure, accomplish the following:

(a) Within 6 months after the effective date of this AD, modify the engine left- and right-hand fuel shutoff valve, the interconnect valve, the crossfeed valve, and the de-fuel shutoff valve from a part number (P/N) AV16B2117B-2 (SAAB P/N 9303149-002) configuration to a P/N AV16B2117B-4 (SAAB P/N 9303149-004) configuration, by removing the existing actuator assembly, P/N 130001C, and installing a new, improved actuator assembly, P/N 130003N; and perform a functional test of the modified valves once they are installed; in accordance with SAAB Service Bulletin SAAB 340-28-016, dated October 21, 1992.

(b) As of the effective date of this AD, no person shall install a fuel shutoff valve assembly having P/N AV16B2117B-2 (SAAB P/N 9303149-002) on any airplane.

(c) 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, Standardization Branch, ANM-113. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Standardization Branch, ANM-113.

NOTE: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113.

(d) 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.

(e) The replacement actions shall be done in accordance with SAAB Service Bulletin SAAB 340-28-016, dated October 21, 1992. 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 SAAB-Aircraft AB, Product Support, S581.88, Link ping, Sweden. 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.

(f) This amendment becomes effective on June 17, 1994.

A proposal to amend part 39 of the Federal Aviation Regulations to include an airworthiness directive (AD) that is applicable to certain SAAB Model SAAB 340B series airplanes was published in the Federal Register on November 16, 1993 (58 FR 60413). That action proposed to require replacement of the existing actuator assembly on the motor operated fuel valve assembly with a new, improved actuator assembly, and accomplishment of a functional test of the engine fuel shutoff valve.

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 proposal.

One of the commenters points out that the current name of the airplane manufacturer is "SAAB Aircraft AB." rather than "SAAB-Scania" as was referenced in the proposal. The commenter suggests that all references to the manufacturer be updated accordingly. The FAA concurs and has revised all references in the final rule to indicate "SAAB Aircraft AB."

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 with the change previously described. The FAA has determined that this change will neither increase the economic burden on any operator nor increase the scope of the AD.

The FAA estimates that 6 airplanes of U.S. registry will be affected by this AD, that it will take approximately 3 work hours per airplane to accomplish the required actions, and that the average labor rate is $55 per work hour. Required parts will be provided by the airplane manufacturer at no cost to operators. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $990, or $165 per airplane.

The total 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 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 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 14 CFR part 39 of the Federal Aviation Regulations as follows:

PART 39 - AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89.

39.13 - [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive: