AD 94-05-04

A proposal to amend part 39 of the Federal Aviation Regulations to include an airworthiness directive (AD) that is applicable to certain Boeing Model 727 series airplanes was published in the Federal Register on August 31, 1993 (58 FR 45861). That action proposed to require incorporation of certain structural modifications.

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

One commenter supports the proposed rule.

One commenter requests that the FAA issue one rulemaking action that would combine the requirements of this proposal, which proposes to require the modifications listed in Boeing Document Number D6-54860, "Aging Airplane Service Bulletin Structural Modification and Inspection Program - Model 727," Revision G, dated March 5, 1993, with the proposal to require the inspections listed in that Boeing Document. That rulemakingaction was proposed in AD Docket 93-NM-72-AD (58 FR 45863, August 31, 1993). This commenter requests that these two rulemaking actions be combined with AD 90-06-09, Amendment 39-6488 (55 FR 8370, March 7, 1990), which references Revision C, of Boeing Document Number D6-54860, dated December 11, 1989, for purposes of easing operators' tracking compliance with these three separate rulemaking actions. The FAA does not concur. The FAA's normal policy in this regard is that when an AD requires a substantive change, such as a change in the existing AD's requirements, the existing AD (AD 90-06-09) is superseded by being removed from the system and a new AD added. However, to supersede the existing AD and replace it with a new one having a new AD number, would serve no purpose in terms of the ability of affected operators to track compliance with the AD and maintain accurate records of compliance. In consideration of the consequent workload associated with revising maintenance records to enter new AD numbers to demonstrate compliance with requirements accomplished previously, the FAA has determined that a less burdensome approach is to issue a separate AD. This final rule is issued as a separate AD action since combining these rulemaking actions would necessitate recordkeeping changes to reflect new AD numbers. The FAA does not intend to supersede or revise AD 90-06-09. As such, the modifications required by this AD do not supersede the requirements of AD 90-06-09; operators must continue to comply with the requirements of that AD. Furthermore, the FAA's intent in keeping the requirement to accomplish the inspections listed in the Boeing Document separated from the requirement to accomplishment the modifications listed in the Boeing Document was to minimize the recordkeeping burden to the operators; i.e., operators will not be required to make recordkeeping changes to their inspection entries whenever revisions are made to modification requirements and vice versa.Several commenters request that proposed paragraph (a) be revised to clarify that only the structural modifications listed in Appendices A.3, B.3, and C.3 of the Boeing Document must be accomplished. Since the proposal stated that the modifications were listed in "Section 3 and Appendices A., B., and C.," of the Boeing Document, these commenters contend that the possibility exists for misinterpretation. Section 3 of the Boeing Document lists structural modifications that are required by AD 90-06-09 and Appendices A. and B. list structural inspections that are included in AD Docket 93-NM-72-AD (58 FR 45863, August 31, 1993), which proposes to require structural inspections of older airplanes. The FAA concurs. The FAA finds that these commenters' suggestion to reference the specific appendices of the Boeing Document (rather than the generalization cited in the proposal) would avoid any possibility for misinterpretation. Therefore, paragraph (a) of the final rule has been revisedaccordingly.

One commenter requests that the proposal be revised to permit deviations to the modifications required by proposed paragraph (a) to be accomplished in accordance with FAA-approved data, e.g., Structural Repair Manuals; FAA Form 8110-3, Statement of Compliance with the Federal Aviation Regulations; etc. The commenter's intent for requesting this change is to gain authorization to make minor deviations, such as oversizing fasteners and substituting materials, without obtaining approval for an alternative method of compliance for each deviation. The FAA does not concur. The FAA has determined that the Manager, Seattle Aircraft Certification Office, must approve any such deviations to the AD's requirements. Given that possible new relevant issues might be revealed during this process, it is imperative that the FAA, at this level, have such feedback. Only by reviewing deviation approvals can the FAA be assured of this feedback and of the adequacy of the repair methods. However, when the FAA has obtained an adequate sampling of the quality, type, and extent of repairs being made as a result of this AD, the FAA anticipates that it will, at some future date, authorize manufacturer's Designated Engineering Representatives to approve minor deviations to the modifications required by this final rule, as it has done in the past regarding the requirements of AD 90-06-09, and other aging fleet AD's.

One commenter noted that the economic impact information in the proposal reflects an extremely low estimate ($55 per work hour) of the labor rate incurred by industry. This commenter stated that a more realistic labor rate would be in the range of $60 to $100 per work hour. From this comment, the FAA infers that the commenter is requesting that the economic impact information be revised and computed using a higher labor rate figure. The FAA does not concur. The figure of $55 per work hour used in the economic impact information, below, was based upon data provided to the FAA by various operators in industry. As such, the FAA uses this figure based upon the best data available to date.

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.

There are approximately 1,635 Model 727 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 70 airplanes of U.S. registry will be affected by this AD within the initial threshold of 4 years. The cost to modify each airplane is estimated to be $260,155. This cost includes the price of modification kits, which is $186,180 per airplane, and the estimated number of work hours to accomplish the modifications, which is 1,345 work hours at $55 per work hour. It does notinclude downtime, planning, set up, familiarization, or tool acquisition costs. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $18,210,850 over the 4-year time period.

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 FAA recognizes that the obligation to maintain aircraft in an airworthy condition is vital, but sometimes expensive. Because AD's require specific actions to address specific unsafe conditions, they appear to impose costs that would not otherwise be borne by operators. However, because of the general obligation of operators to maintain aircraft in an airworthy condition, this appearance is deceptive. Attributing those costs solely to the issuance of this AD is unrealistic because, in the interest of maintaining safeaircraft, most prudent operators would accomplish the required actions even if they were not required to do so by the AD.

A full cost-benefit analysis has not been accomplished for this AD. As a matter of law, in order to be airworthy, an aircraft must conform to its type design and be in a condition for safe operation. The type design is approved only after the FAA makes a determination that it complies with all applicable airworthiness requirements. In adopting and maintaining those requirements, the FAA has already made the determination that they establish a level of safety that is cost- beneficial. When the FAA, as in this AD, makes a finding of an unsafe condition, this means that this cost-beneficial level of safety is no longer being achieved and that the required actions are necessary to restore that level of safety. Because this level of safety has already been determined to be cost-beneficial, a full cost-benefit analysis for this AD would be redundant and unnecessary.

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: