AD 98-20-15

This amendment adopts a new airworthiness directive (AD), applicable to certain Saab Model SAAB 340B series airplanes, that requires a one-time inspection for moisture or other contamination of a certain wiring harness, electrical relay, and relay socket; a one-time inspection for electrical damage of the same electrical relay and socket; corrective actions, if necessary; and replacement of certain nut plates with new, improved parts. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent a short circuit caused by fluid leakage, which could result in inability to retract the landing gear or require the use of emergency extension.

Final rule

98-20-15 SAAB AIRCRAFT AB: Amendment 39-10782. Docket 98-NM-176-AD.
Applicability: Model SAAB 340B series airplanes, manufacturer serial numbers 380 through 499 inclusive; certificated in any category.
NOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (b) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.
Compliance: Required as indicated, unless accomplished previously.
To prevent a short circuit caused by fluid leakage, which could result in inability to retract the landing gear or require the use of emergency extension, accomplish the following:
(a) Within 400 flight hours after the effective date of this AD, accomplish the actions required by paragraphs (a)(1), (a)(2), (a)(3), and (a)(4) of this AD, in accordance with Saab Service Bulletin 340-32-115, dated April 7, 1998, or Revision 01, dated August 12, 1998. As of the effective date of this AD, Revision 01 of the service bulletin shall be used.
(1) Perform a detailed visual inspection to detect moisture or other contamination of the electrical wiring harness above relay consoles 305VU and 306VU. If any moisture or other contamination is found, prior to further flight, clean the wiring harness.
(2) Perform a detailed visual inspection to detect moisture or other contamination of electrical relay 15GA and its socket. If any moisture or other contamination is found,prior to further flight, accomplish corrective actions.
(3) Perform a detailed visual inspection for electrical damage of electrical relay 15GA and its socket. If any sign of electrical damage (arcing, discoloration, or charring) is detected, prior to further flight, replace the existing relay and socket with new parts.
(4) Replace the existing nut plates on the floor of the cockpit with new, improved nut plates, on the left and right sides of the airplane.
(b) 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, International Branch, ANM-116, FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, International Branch, ANM-116.
NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, ifany, may be obtained from the International Branch, ANM-116.
(c) 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.
(d) The actions shall be done in accordance with Saab Service Bulletin 340-32-115, dated April 7, 1998, or Saab Service Bulletin 340-32-115, Revision 01, dated August 12, 1998. 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, SAAB Aircraft Product Support, S-581.88, 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.
NOTE 3: The subject of this AD is addressed in Swedish airworthiness directive SAD 1-125, dated April 7, 1998.
(e) This amendment becomes effective on October 27, 1998.

FOR FURTHER INFORMATION CONTACT: Norman B. Martenson, Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2110; fax (425) 227-1149. 3

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 certain Saab Model SAAB 340B series airplanes was published in the Federal Register on July 16, 1998 (63 FR 38353). That action proposed to require a one-time inspection for moisture or other contamination of a certain wiring harness, electrical relay, and relay socket; a one-time inspection for electrical damage of the same electrical relay and socket; corrective actions, if necessary; and replacement of certain nut plates with new, improved parts.

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

Request to Revise Descriptive Language
One commenter notes that the description of the incident that appeared in the Discussion section of the preamble to the notice of proposed rulemaking (NPRM) refers to ". . . the flightcrew being unable to extend and lock down the landing gear." The commenter notes that it was the normal extension operation that failed, and that the crew used emergency extension and made a normal landing. The commenter suggests that a more accurate description would be "the flightcrew having to use emergency extension of the landing gear." The FAA acknowledges that the commenter's wording is more accurate. Since the Discussion section is not restated in this final rule, no change to the final rule is necessary.

The same commenter also suggests that the description of the unsafe condition that appeared in the NPRM be revised to read ". . . which could result in inability to retract the landing gear or require the use of emergency extension . . ." The FAA concurs with this suggestion and has revised the pertinent wording throughout the final rule.

Request to Reference Latest Saab Service Bulletin
In addition, the commenter requests that paragraph (a) of the proposed AD be revised to reference Revision 01 of Saab Service Bulletin 340-32-115, dated August 12, 1998. The commenter notes that the reason for this revision was to clarify identification of wire numbers. The FAA concurs. Since issuance of the NPRM, Saab has issued Revision 01 of the subject service bulletin. The inspections, replacement, and corrective actions described in Revision 01 of the service bulletin are essentially identical to those described in the original version of the service bulletin (which was referenced in the NPRM as the appropriate source of service information). As noted by the commenter, the only relevant change is to clarify wire numbers. Therefore, the FAA has revised paragraph (a) of the final rule to reference Revision 01 of the subject service bulletin as an additional source of service information.
Conclusion
After careful review of the available data, including the comments noted above, the FAA has determined that air safety andthe public interest require the adoption of the rule with the changes described previously. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.
Cost Impact
The FAA estimates that 120 Model SAAB 340B series airplanes of U.S. registry will be affected by this AD.
It will take approximately 1 work hour per airplane to accomplish the required inspections, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the inspections required by this AD on U.S. operators is estimated to be $7,200, or $60 per airplane.
It would take approximately 3 work hours per airplane to accomplish the required replacement, at an average labor rate of $60 per work hour. Required parts will be provided by the manufacturer at no cost to operators. Based on these figures, the cost impact of the replacement required by this AD on U.S. operators is estimated to be $21,600, or $180 per airplane.
The cost impact figures discussed above are 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.
Regulatory Impact
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 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: 2. 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:

U.S. Department of Transportation Federal Aviation Administration The following Airworthiness Directive issued by the Federal Aviation Administration in accordance with the provisions of Federal Aviation Regulations, Part 39, applies to an aircraft model of which our records indicate you may be the registered owner. Airworthiness Directives affect aviation safety and are regulations which require immediate attention. You are cautioned that no person may operate an aircraft to which an Airworthiness Directive applies, except in accordance with the requirements of the Airworthiness Directive (reference FAR Subpart 39.3).