AD 96-11-04

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 McDonnell Douglas Model DC-9 and Model DC-9-80 series airplanes, Model MD-88 airplanes, and C-9 (military) series airplanes was published in the Federal Register on January 31, 1996 (61 FR 3341). That action proposed to require modification of the slant panel insulation blankets on the slant pressure panel of the main landing gear. That action also proposed to require a visual inspection to detect discrepancies of the left and right seal assemblies of the overwing emergency exit door, and replacement of the discrepant door seal.

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

Support for the Proposal

Two commenters support the proposed rule.

Requests to Extend the Compliance Time

Several commenters request that the compliance time for accomplishment of the modification be extended from the proposed 24 months. These commenters request an extension to as much as 36 months, which will allow the modification to be accomplished during a regularly scheduled heavy maintenance check when the airplanes are brought to main base for an extended hold. Two of these commenters state that they would have to special schedule their fleet in order to accomplish the modification within the proposed compliance time; this would entail considerable additional expenses.

After consideration of all the available information, the FAA cannot conclude that an extension of the proposed compliance time is warranted. In developing an appropriate compliance time for this action, the FAA considered not only the degree of urgency associated with addressing the subject unsafe condition, but the availability of required parts and the practical aspect of accomplishing the requiredmodification within an interval of time that parallels normal scheduled maintenance for the majority of affected operators. Further, the proposed compliance time of 24 months was arrived at initially with the concurrence of affected operators, the manufacturer, and the FAA. In light of this, and in consideration of the amount of time that has already elapsed since issuance of the original notice, the FAA has determined that further delay of accomplishment of the requirements of this final rule is not appropriate. However, under the provisions of paragraph (b) of the final rule, the FAA may approve requests for adjustments to the compliance time if data are submitted to substantiate that such an adjustment would provide an acceptable level of safety.

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 as proposed.

Cost Impact

Thereare approximately 1,500 McDonnell Douglas Model DC-9 and Model DC-9-80 series airplanes, Model MD-88 airplanes, and C-9 (military) series airplanes of the affected design in the worldwide fleet. The FAA estimates that 1,000 airplanes of U.S. registry will be affected by this AD, that it will take approximately 8 work hours 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 $480,000, or $480 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 substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution ofpower 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 USC 106(g), 40113, 44701.

§ 39.13 - (Amended)

2. Section 39.13 is amended by adding the following new airworthiness directive: