Discussion
What events have caused this AD? The Federal Office for Civil Aviation (FOCA), which is the airworthiness authority for Switzerland, recently notified FAA that an unsafe condition may exist on certain Pilatus Model PC-7 airplanes. The FOCA reports that there have been 11 reports of damaged fuel boost pump wire leads from 9 Model PC-12 airplanes that have a similar type design. Further, the FOCA reports that it is possible that the wire leads to the left and right fuel pumps are damaged. This could possibly cause electrical arcs from the leads in an air/fuel mixture.
What is the potential impact if FAA took no action? Any electrical arcing could lead to a fire or explosion in the fuel tank.
Has FAA taken any action to this point? We issued a proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to certain Pilatus Model PC-7 airplanes with any Lear Romec RR53710B type or Lear Romec RR53710K fuel booster pump (Pilatus part number 968.84.11.401; 968.84.11.403; or 968.84.11.404) installed. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on August 20, 2004 (69 FR 516161). The NPRM proposed to require you to check the airplane logbook to determine whether any installed fuel booster pump has been modified with spiral wrap to protect the wire leads and has the suffix letter "B" added to the serial number of the fuel booster pump identification plate. If any installed fuel booster pump has not been modified, you are required to inspect any installed fuel booster pump wire lead for defects; if defects are found, replace the fuel booster pump with a modified fuel booster pump with spiral wrap that protects the wire leads; or if no defects are found, install spiral wrap to protect any wire leads and add the suffix letter "B" to the serial number of the fuel booster pump identification plate. The pilot is allowed to do the logbook check. If the pilot can positively determine that the fuel booster pump wire leads with spiral wrap are installed following the service information and that the suffix letter "B" is included in the serial number of the fuel booster pump identification plate, no further action is required.
Comments
Was the public invited to comment? We provided the public the opportunity to participate in developing this AD. We received no comments on the proposal or on the determination of the cost to the public.
Conclusion
What is FAA's final determination on this issue? We have carefully reviewed the available data and determined that air safety and the public interest require adopting the AD as proposed except for minor editorial corrections. We have determined that these minor corrections:
--Are consistent with the intent that was proposed in the NPRM for correcting the unsafe condition; and
--Do not add any additional burden upon the public than was already proposed in the NPRM.
Changes to 14 CFR Part 39--Effect on the AD
How does the revision to 14 CFR part 39 affect this AD? On July 10, 2002, the FAA published a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs the FAA's AD system. This regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance. This material previously was included in each individual AD. Since this material is included in 14 CFR part 39, we will not include it in future AD actions.
Costs of Compliance
How many airplanes does this AD impact? We estimate that this AD affects 10 airplanes in the U.S. registry.
What is the cost impact of this AD on owners/operators of the affected airplanes? We estimate the following costs to do the inspection:
Labor cost
Parts cost
Total cost per airplane
Total cost on U.S. operators
1 workhour x $65 per hour = $65
Not applicable
$65
$65 x 10 = $650.
We estimate the following costs to do any necessary replacement of any fuel boost pump, including the installation of any wire wrap, that will be required based on the results of the inspection. We have no way of determining the number of airplanes that may need this installation:
Labor cost
Parts cost
Total cost per airplane
5 workhours x $65 per hour = $325
$2,800 for each fuel booster pump
$2,800 x $325 = $3,125 for each fuel booster pump installation.
Regulatory Findings
Will this AD impact various entities? We have determined that this AD will not have federalism implications under Executive Order 13132. This AD 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.
Will this AD involve a significant rule or regulatory action? For the reasons discussed above, I certify that this AD:
1. Is not a "significant regulatory action" under Executive Order 12866;
2. Is not a "significant rule" under the 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.
We prepared a summary of the costs to comply with this AD and placed it in the AD Docket. You may get a copy of this summary by sending a request to us at the address listed under ADDRESSES. Include "Docket No. FAA-2004-18579; Directorate Identifier 2004-CE-19-AD" in your request.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, under 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. FAA amends 39.13 by adding a new AD to read as follows: