AD 99-27-08

This amendment adopts a new airworthiness directive (AD), applicable to certain Saab Model SAAB SF340A and SAAB 340B series airplanes, that requires repetitive inspections of the control quadrant for loose screws, and replacement of the control quadrant with a modified part, which constitutes terminating action for the repetitive inspections. 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 the power levers from binding due to the backing out of screws that secure the solenoid bracket within the flight idle stop assembly, which could result in the malfunction of the flight idle stop mechanism and the override function, and the inability to move the power levers aft of flight idle.

Final rule

99-27-08 SAAB AIRCRAFT AB: Amendment 39-11489. Docket 99-NM-200-AD. December 23, 1999.
Applicability: Model SAAB SF340A series airplanes, serial numbers 004 through 159 inclusive; and Model SAAB 340B series airplanes, series number 160 through 459 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 (e) 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 the power levers from binding due to the backing out of screws that secure the solenoid bracket within the flight idle stop assembly, which could result in the malfunction of the flight idle stop mechanism and the override function, and the inability to move the power levers aft of flight idle, accomplish the following:

Inspection
(a) Within 800 flight hours after the effective date of this AD, perform a borescopic inspection of the control quadrant for loose screws, in accordance with Saab Service Bulletin 340-76-043, Revision 01, dated July 29, 1999. If no loose screws are found, repeat the inspection thereafter at intervals not to exceed 800 flight hours, until the requirements of paragraph (c) are accomplished.

NOTE 2: Saab Service Bulletin 340-76-043, dated July 2, 1999, references Adams Rite Aerospace Service Letter General SL-01, dated April6, 1999, as an additional source of service information to accomplish the inspection.

NOTE 3: Inspections and replacements accomplished prior to the effective date of this AD in accordance with Saab Service Bulletin 340-76-043, dated July 2, 1999, are considered acceptable for compliance with the applicable action specified in this amendment.

Corrective Action
(b) If any loose screw is found during any inspection performed in accordance with paragraph (a) of this AD, prior to further flight, replace the existing control quadrant with a modified control quadrant, or with a serviceable control quadrant that has been inspected and found to have no loose screws, in accordance with Saab Service Bulletin 340-76-043, Revision 01, dated July 29, 1999.

Terminating Action
(c) Within 8,000 flight hours or 6 years after the effective date of this AD, whichever occurs earlier: Replace the existing control quadrant with a modified control quadrant in accordance with Saab ServiceBulletin 340-76-043, Revision 01, dated July 29, 1999. Such replacement constitutes terminating action for the repetitive inspections required by paragraph (a) of this AD.

Spares
(d) As of the effective date of this AD, no person shall install a control quadrant on any airplane, unless the quadrant has been modified, or has been inspected and found to have no loose screws, in accordance with the requirements of this AD.

Alternative Methods of Compliance
(e) 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 4: Information concerning the existence of approved alternative methods of compliance with this AD, ifany, may be obtained from the International Branch, ANM-116.

Special Flight Permits
(f) 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.

Incorporation by Reference
(g) The actions shall be done in accordance with Saab Service Bulletin 340-76-043, Revision 01, dated July 29, 1999. 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, Linkoping, 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 5: The subject of this AD is addressed in Swedish airworthiness directive SAD No. 1-143, dated July 2, 1999.

(h) This amendment becomes effective on February 8, 2000.

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 SF340A and SAAB 340B series airplanes was published in the Federal Register on September 13, 1999 (64 FR 49418). That action proposed to require repetitive inspections of the control quadrant for loose screws, and replacement of the control quadrant with a modified part, which would terminate action for the repetitive inspections.

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

Restatement of Unsafe Condition
One commenter, the manufacturer, requests that the proposed AD be revised to restate the identified unsafe condition. The commenter states that malfunction of the automatic flight idle stop mechanism would result in the inability to move the power levers aft of flight idle, rather than "to flight idle," as stated in the proposed AD. The commenter also notes that, should the automatic system fail, it can be overridden by the emergency override function. The commenter suggests that pertinent sections of the AD be revised to read ". . . could result in malfunction of the automatic flight idle stop mechanism and the override function, preventing the power lever to be moved aft of flight idle." The FAA concurs that the restatement suggested by the commenter is a more accurate reflection of the unsafe condition identified in this AD, and has revised the final rule accordingly.

Revision of Corrective Action
The same commenter requests that paragraph (b) of the proposed AD be revised to allow installation of an unmodified quadrant, provided it has been inspected without discrepancies detected, and provided it is subject to repetitive inspections until it has been modified. The commenter states that it believes that an acceptable level of safety can be maintained if these conditions are followed. This would allow a quadrant other than a modified quadrant to be installed in the event that loose screws are found in the installed quadrant during any inspection required by paragraph (a) of the AD.

The FAA concurs that installation of any control quadrant that has been modified, or that has been inspected in accordance with the requirements of this AD and found to have no loose screws, is an acceptable corrective action to address the identified unsafe condition. The FAA has revised paragraph (b) of the AD to require such action prior to further flight if loose screws are found in a control quadrant. The FAA also has revised paragraph (d) of the AD, which addresses installation of spare quadrants, to require such action for any control quadrant prior to installation on any airplane.

Revision of Spares Paragraph
The commenter also advises the FAA that the version of the proposed AD that was published inthe Federal Register omitted certain information pertinent to paragraph (d) of the AD and should be corrected. The commenter states that the list of combinations of acceptable part numbers and reference letters is incorrect, and the list is missing several combinations. The FAA acknowledges the inadvertent typographical error identified in the Federal Register version of the proposed AD. The omission related to certain modified control quadrants acceptable for installation on the airplane. However, as previously described, paragraph (d) of the AD has been broadened to allow installation of both modified and certain unmodified quadrants. Therefore, the list of combinations of part numbers and reference letters is now omitted, and further change to paragraph (d) of the AD is unnecessary.

Cost Estimate
The same commenter states that it believes an estimate of one work hour for the inspection, as provided in the cost impact information of the proposed AD, to be an overestimate.The FAA infers that the commenter is requesting that the cost estimate be revised downward. The FAA does not concur. The estimate of 1 work hour was obtained by rounding upward from the referenced service bulletin's Manpower estimate of 15 minutes. This practice is followed for simplicity in cost estimating, and does not significantly affect the total cost to operators. No change to the AD is necessary.

Change to the Proposed AD
Paragraph (a) of the proposed AD cites Saab Service Bulletin 340-76-043, Revision 01, dated July 29, 1999, as the appropriate source of service information. However, reference to this revision was inadvertently omitted from paragraphs (b) and (c) of the proposed AD. The procedures described in Revision 01 of the service bulletin are identical to those contained in the original issue of the service bulletin, dated July 2, 1999; and NOTE 3 in the AD gives credit to operators that may have previously accomplished required actions in accordance with theoriginal version. The FAA has revised paragraphs (b) and (c) of the AD to reference Revision 01 of the service bulletin.

Conclusion
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 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 289 airplanes of U.S. registry will be affected by this AD, that it will take approximately 1 work hour per airplane to accomplish the required inspection, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the required inspection on U.S. operators is estimated to be $17,340, or $60 per airplane, per inspection cycle. The FAA estimates that it will take approximately 4 work hours per airplane to accomplish the required replacement, at an average labor rate of $60 per work hour. Required parts will be supplied by the parts manufacturer at no cost to the operators. Based on these figures, the cost impact of the required replacement on U.S. operators is estimated to be $69,360, or $240 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:
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: