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 de Havilland Model DHC-8-100 and -300 series airplanes, was published in the Federal Register on September 21, 1994 (59 FR 48408). That action proposed to require a visual inspection to verify the integrity of the shield grounds for the cable harness of the EEC, and correction of any discrepancy. That action also proposed to require measurement of the electrical resistance of certain shield grounds, and repair, if necessary.
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 requests that the proposed 45-day compliance time in paragraph (b) of the proposed AD be extended to permit operators to schedule the proposed actions according to the size of their individual fleets and, specifically, to allow up to 165 days for a fleet-wide inspection. The commenter bases this request on the following factors:
1. The commenter states that, to accomplish the proposed measurement requirement, the use of a low resistance ohm meter (micro-ohm) is necessary. The commenter has only one low resistance ohm meter to perform the measurement of all the airplanes in its fleet. With only one micro-ohm meter available, the commenter could inspect only a limited number of its fleet of airplanes during its regularly scheduled maintenance visits, and would not be able to accomplish the proposed inspections within the proposed 45-day compliance time. Further, the commenter does not believe it should have to purchase or otherwise obtain additional units to satisfy the requirements of the proposed AD.
2. The commenter states that the actions specified in the service bulletin could not be accomplished in less than 25 hours and, that based on the amount of time available for a scheduled maintenance visit, up to 4 visits may be required to complete the inspection. The commenter is concerned about these additional expenses that would be associated with this action.
The FAA does not concur with the commenter's request to extend the compliance time. 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 normal maintenance schedules for timely accomplishment of the actions required by the final rule for all affected airplanes to continue to operate without compromising safety. In consideration of these items, the FAA has determined that the 45-day compliance time represents an average maintenance interval for the affected fleet, during which time the required inspections, measurement, repair, and restoration can reasonably be accomplished and an acceptable level of safety can be maintained. However, under the provisions of paragraph (e) 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.
As for the commenter's concern regarding the expenses associated with accomplishing the requirements of this AD, the FAA recognizes that the obligation to maintain aircraft in an airworthy condition is vital, but sometimes expensive. Because AD's require specific actions (such as testing with special equipment) to address specific unsafe conditions as required in this rule, they appear to impose costs that would not otherwise be borne by operators. Attributing those costs solely to the issuance of this AD is unrealistic because, in the interest of maintaining safe aircraft, prudent operators would accomplish the required actions in a timely manner even if they were not required to do so by the AD.
One commenter requests that a certain procedure for repairing frayed or broken harnesses be referenced in the proposed rule as an acceptable means of repair. The commenter states that accomplishment of this repair procedure may be necessary in the course of performing the required inspections. The commenter notes that this repair procedure is not included in any service bulletin or manual.
The FAA does not concur. The FAA does not consider it appropriate to include various provisions in an AD applicable to a single operator. Paragraph (e) of this AD provides for the approval of alternative methods of compliance to address these types of unique circumstances.
As a result of recent communications with the Air Transport Association (ATA) of America, the FAA has learned that, in general, some operators may misunderstand the legal effect of AD's on airplanes that are identified in the applicability provision of the AD, but that have been altered or repaired in the area addressed by the AD. The FAA points out that all airplanes identified in the applicabilityprovision of an AD are legally subject to the AD. If an airplane has been altered or repaired in the affected area in such a way as to affect compliance with the AD, the owner or operator is required to obtain FAA approval for an alternative method of compliance with the AD, in accordance with the paragraph of each AD that provides for such approvals. A note has been included in this notice to clarify this long-standing requirement.
The FAA has recently reviewed the figures it has used over the past several years in calculating the economic impact of AD activity. In order to account for various inflationary costs in the airline industry, the FAA has determined that it is necessary to increase the labor rate used in these calculations from $55 per work hour to $60 per work hour. The economic impact information, below, has been revised to reflect this increase in the specified hourly labor rate.
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.
The FAA estimates that 141 airplanes of U.S. registry will be affected by this AD, that it will take approximately 16 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 total cost impact of the AD on U.S. operators is estimated to be $135,360, or $960 per airplane.
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 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 bythe 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. 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: