Discussion
What Events Have Caused This AD?
We have received several reports that a condition exists in some of the electrical control modules in the airplane electrical system.
FAA analysis indicates that there is inadequate clearance and inadequate electrical isolation between the load terminal and metal case. The modules load terminal is cutting through the rubber insulating grommet and contacting the module's metal case. This causes the electrical short circuit and electrical arcing.
The following electrical system components are potentially affected by this condition: engine start; strobe light; left/right taxi light; liquid crystal display (LCD) dimming; dual flasher (recognition light); left/right pitot heat; avionics dimming (Bezel buttons for radios); prop heat; left/right fuel pump; position light landing light; instrument panel light dimming; ice light; vent defog (vent blower); hi/low blower; stall heat; and dimmer switch lighting (overhead switch panel switches).
What Is the Potential Impact If FAA Took No Action?
If not corrected, short circuit failure and electrical arcing of the electronic control modules could result in loss of the electrical systems components or burning of wiring insulation and cause smoke in the cockpit. This condition could lead to the inability to properly control the airplane.
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 Piper Model PA-46-500TP airplanes. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on October 9, 2003 (68 FR 58289). The NPRM proposed to require you to replace all electronic control modules in the airplane electrical system with newly designed modules.
Comments
Was the Public Invited To Comment?
We provided the public the opportunity to participate in developing this AD. The following presents the comment received on the proposal and FAA's response to the comment:
Comment Issue: Revise Costs of Compliance
What Is the Commenter's Concern?
The manufacturer recommends revising the costs of compliance based on the following, updated information:
--There are 152 airplanes affected by this AD instead of 130 as stated in the proposed AD;
--Although all affected airplanes will have the parts modified under warranty, 108 of the affected airplanes will get warranty credit for the labor costs to have the parts removed, replaced, and tested after reinstallation;
--The workhours for labor are 12 instead of 22 as stated in the proposed AD.
--The total cost on U.S. operators will be $34,320 instead of $185,900 as stated in the proposed AD based on 44 affected airplanes not covered under warranty for the labor costs, which are recalculated using 12 workhours.
What Is FAA's Response to the Concern?
We agree that the new cost data provided by the manufacturer be used in the AD.
We are changing the final rule AD action accordingly.
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 152 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 accomplish the modification:
Labor cost
Parts cost
Total cost per airplane
Total cost on U.S. operators
12 workhours $65 per hour = $780
Parts are covered under warranty by the manufacturer for all affected airplanes.
$780
$780 44 = $34,320.
There are 108 of the affected airplanes that are also covered under warranty for the labor costs to have the parts removed, replaced, and tested after reinstallation.
Regulatory Findings
Will This AD Impact Various Entities?
We have determined that this AD will not havefederalism 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"AD Docket No. 2003-CE-32-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: