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CFR Citation: 14 CFR Part 39

Docket ID: [Docket No. FAA-2008-1085; Directorate Identifier 2008-CE-057-AD]

RIN ID: RIN 2120-AA64

NOTICE: PROPOSED RULES

ACTION: Airworthiness Directives:

DOCUMENT ACTION: Notice of proposed rulemaking (NPRM).

SUBJECT CATEGORY: Airworthiness Directives; Piper Aircraft, Inc. Models PA-46-350P, PA-46R-350T, and PA-46-500TP Airplanes

DATES: We must receive comments on this proposed AD by December 9, 2008.

DOCUMENT SUMMARY: We propose to adopt a new airworthiness directive (AD) for certain Piper Aircraft, Inc. (Piper) Models PA46350P, PA46R350T, and PA46500TP airplanes. This proposed AD would require you to install a stall warning heat control modification kit. This proposed AD results from ice forming on the stall vane heater during flights into icing conditions with the landing gear down. We are proposing this AD to prevent ice from forming on the stall vane, which may result in failure of the stall warning system. This failure could result in the pilot being unaware of an approaching stall situation.

SUMMARY: Piper Aircraft, Inc. Models PA-46-350P, PA-46R-350T, and PA-46-500TP Airplanes,

SUPPLEMENTAL INFORMATION

We invite you to send any written relevant data, views, or arguments regarding this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include the docket number, ``FAA 20081085; Directorate Identifier 2008CE057AD'' at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

We will post all comments we receive, without change, to http:// www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive concerning this proposed AD.

Discussion

Recently, it was discovered on a Piper Model PA46500TP airplane that the stall warning did not activate when expected. Upon landing, the stall vane was found iced over, which temporarily disabled the lift detector.

The design of the Model PA46500TP airplane includes a landing gear uplock switch. When this switch is not
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engaged, the electrical flow to the stall vane deicing element is reduced. After reviewing the maintenance manual, it was determined that the system was functioning as designed.

Piper changed the stall warning heat wiring schematic in Models PA 46350P, PA46R350T, and PA46500TP airplanes. All of the previous Piper PA46 series airplanes have a twostage stall vane heater. They are wired with a squat switch such that when stall warning heat is in the on position, the heater sets to low when there is weight on wheels (when the aircraft is on the ground) and switches to high when there is no weight on the wheels (during all phases of flight).

Instead of using the squat switch to change the heat setting from low to high, Piper Models PA46350P, PA46R350T, and PA46500TP airplanes use the landing gear uplock switch. When using this switch and the stall warning heat is in the on position, the heater sets to low when the landing gear doors are open and switches to high when the landing gear doors are closed.

This condition, if not corrected, could result in failure of the stall warning system. This failure could result in the pilot being unaware of an approaching stall situation.

Relevant Service Information

We have reviewed Piper Mandatory Service Bulletin No. 1192, dated September 15, 2008.

The service information specifies installing Stall Warning Heat Control Modification Kit, Piper part number 88452002.

FAA's Determination and Requirements of the Proposed AD

We are proposing this AD because we evaluated all information and determined the unsafe condition described previously is likely to exist or develop on other products of the same type design. This proposed AD would require you to install a stall warning heat control modification kit.

Costs of Compliance

We estimate that this proposed AD would affect 803 airplanes in the U.S. registry.

We estimate the following costs to do the proposed modification: Total cost per Total cost on Labor cost Parts cost airplane U.S. operators 1.5 workhours x $80 per hour = $120......................... $95 $215 $172,645

Warranty credit may be given to the extent noted in the service bulletin.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, ``General requirements.'' Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

Regulatory Findings

We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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.

For the reasons discussed above, I certify that the proposed regulation:

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 regulatory evaluation of the estimated costs to comply with this proposed AD and placed it in the AD docket. Examining the AD Docket

You may examine the AD docket that contains the proposed AD, the regulatory evaluation, any comments received, and other information on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone (800) 6475527) is located at the street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt. List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows: PART 39AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec. 39.13 [Amended]

2. The FAA amends Sec. 39.13 by adding the following new AD: Piper Aircraft, Inc.: Docket No. FAA20081085; Directorate
Identifier 2008CE057AD.
Comments Due Date
(a) We must receive comments on this airworthiness directive (AD) action by December 9, 2008.
Affected ADs
(b) None.
Applicability
(c) This AD applies to the following airplane models and serial numbers that are certificated in any category:
Model Serial Nos. PA46350P........................... 4622001 through 4622200 and 4636001 through 4636445. PA46R350T.......................... 4692001 through 4692054. PA46500TP.......................... 4697001 through 4697365. Unsafe Condition
(d) This AD results from ice forming on the stall vane heater during flights into icing conditions with the landing gear down. We are issuing this AD to prevent ice from forming on the stall vane, which may result in failure of the stall warning system. This failure could result in the pilot being unaware of an approaching stall situation.
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Compliance
(e) To address this problem, you must do the following, unless already done:
Actions Compliance Procedures Install Stall Warning Heat Control Within the next 100 hours timein As specified in Piper Mandatory Modification Kit, Piper part number service after the effective date of Service Bulletin No. 1192, dated 88452002. this AD. September 15, 2008, following Drawing No. 88452 dated June 19, 2008. Alternative Methods of Compliance (AMOCs)
(f) The Manager, Atlanta Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to

FOR FURTHER INFORMATION CONTACT John Lee, Aerospace Engineer, Federal Aviation Administration, Aircraft Certification Office, One Crown Center, 1895 Phoenix Blvd., Suite 450, Atlanta, Georgia 30349; telephone: (770) 9946736; fax: (770) 7036097.