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 March 15, 2000 (65 FR 13921). That action proposed to require a one-time inspection to detect discrepancies of the flight idle stop override mechanism, and corrective action, if necessary.
Comment Received
Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comment received.
Objection to the Proposal
One commenter, an operator, states that mandating the inspection proposed in this AD has no value and will not contribute to safety. The commenter offers several reasons, described below, for this assertion.
1. The commenter states that the cable that originally stuck [prompting issuance of a related FAA AD, AD 98-08-16, amendment 39-10465 (63 FR 18118, April 14, 1998)], along with the uplock switch and knob, is fully contained within the control quadrant installed on each airplane, and the quadrants are interchangeable among airplanes. The commenter considers it extremely doubtful that the same quadrants are still installed in the airplanes that are specified in the applicability of the proposed AD.
2. The commenter states that the proposed AD does not cover quadrants installed in airplanes with serial numbers above 413, nor does it cover quadrants installed in airplanes that were listed in the original applicability of AD 98-08-16. Yet those quadrants, although not covered in that AD, have the same flight idle stop override mechanism as those installed on airplanes specified in the applicability of the proposed AD, and the commenter asserts that the same safety concern should exist on those airplanes as well.
3. Additionally, the commenter notes the issuance of two other FAA AD's, AD 99-21-31, amendment 39-11377 (64 FR 56426, October 20, 1999), and AD 99-27-08, amendment 39-11489 (65 FR 209, January 4, 2000), that also address the control quadrants. In order to comply with the terminating action for those AD's, operators must remove the quadrant from the airplane, and the quadrant must be modified or replaced. The commenter therefore asserts that a quadrant installed on an airplane when AD 98-08-16 was issued would no longer be installed in its original, unmodified condition.
4. The commenter also states that a Maintenance Review Board (MRB) task already exists to perform a periodic operational check of the flight idle stop override mechanism on all airplanes. The commenter states that this check would find any stiff or frozen cables in the override system; therefore, the intent of the proposed AD is already being met.
FAA Response
The FAA infers that the commenter is requesting that the proposed AD be withdrawn. The FAA does not concur, for the reasons set forth below. Further, the FAA considers that reiteration of the requirements for compliance with airworthiness directives is necessary. After the compliance time specified in an AD has passed, all corrective actions required by that AD must have been accomplished in order to correct the unsafe condition. If an airplane is returned to a configuration that allows the unsafe condition to exist, that airplane is being operated contrary to the requirements of the AD, which is prohibited per section 39.3 of the Federal Aviation Regulations (14 CFR 39.3). The FAA provides specific responses below to each of the commenter's assertions (numbered to correspond with the commenter's issues).
1. AD 98-08-16 refers to Saab Service Bulletin 340-76-041, dated May 29, 1997, and Revision 01, dated July 2, 1997, as the appropriate source of service information for the actions required by that AD. That service bulletin specifies that certain control quadrants (including those held as spares) are to be inspected, and repaired if necessary. Therefore, although control quadrants may have subsequently been interchanged among airplanes, the inspection and corrective actions required by AD 98-08-16 should have been accomplished for all affected quadrants. Additionally, the compliance time for that AD has already passed. If a quadrant is installed on an affected airplane after that date, and the quadrant has not been inspected per the requirements of AD 98-08-16, the airplane is being operated contrary to the requirements of that AD. No change to the final rule is necessary in this regard.
2. The FAA does not concur that additional airplanes are subject to the identified unsafe condition. Saab Service Bulletin 340-76-041 lists airplanes only through serial number (S/N) 413 in the effectivity; airplanes having higher S/N's did not need to be included in this effectivity because they were delivered with correctly functioning control quadrants installed. And, as stated above, for airplanes having higher S/N's that were affected by the requirements of AD 98-08-16, any quadrant installed after the compliance time should have been inspected according to the requirements of that AD. No change to the final rule is necessary in this regard.
3. The FAA acknowledges that other existing AD's may have required replacement of control quadrants with other quadrants. However, as stated above, after the compliance time for each AD has passed, the required corrective actions specified in each AD must have been accomplished for the affected airplanes, and for control quadrants subsequently installed on those airplanes. The FAA acknowledges that the one-time inspection required by this AD may have been previously accomplished as part of compliance with other AD's. In those cases, the requirements of this AD have been complied with, and no further action is required. No change to the final rule is necessary in this regard.
4. The FAA does not concur that the existing MRB task alone is adequate to address the unsafe condition identified in this AD, because the compliance time in the AD is much shorter than the time interval specified for the task in the MRB. However, the FAA has determined that the procedures specified in the MRB task for the operational check may also be used for compliance with the requirements of this AD. A NOTE has been added to the AD to give credit to operators that may have accomplished the MRB task prior to the effective date of this AD.
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 change described previously. The FAA has determined that this change will neither increase the economic burden on any operator nor increase the scope of the AD.
Cost Impact
The FAA estimates that 31 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 actions, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $1,860, or $60 per airplane.
The 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.
Regulatory Impact
The regulations adopted herein will 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 final rule does not have federalism implications under Executive Order 13132.
For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" underExecutive 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: