Document ID: FAA-2011-0639-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: Piper Aircraft, Inc. Models PA-24, PA-24-250, and PA 24-260 Airplanes
Posted Date: 2011-06-22T04:00Z

[Federal Register Volume 76, Number 120 (Wednesday, June 22, 2011)]
[Proposed Rules]
[Pages 36395-36398]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-15543]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-0639; Directorate Identifier 2011-CE-016-AD]
RIN 2120-AA64

Airworthiness Directives; Piper Aircraft, Inc. Models PA-24, PA-
24-250, and PA-24-260 Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for the 
products listed above. This proposed AD would require either 
replacement of the stabilator horn assembly or repetitive inspection of 
the stabilator horn assembly for corrosion or cracks with replacement 
of the stabilator horn assembly if any corrosion or cracks are found. 
This proposed AD was prompted by reports of cracks developing in the 
stabilator horn assembly. We are proposing this AD to detect and 
correct corrosion or cracks in the stabilator horn assembly. Corrosion 
or cracks could lead to failure of the stabilator horn. Consequently, 
failure of the stabilator horn could lead to a loss of pitch control in 
flight.

DATES: We must receive comments on this proposed AD by August 8, 2011.

ADDRESSES: You may send comments by any of the following methods:

[[Page 36396]]

     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this proposed AD, contact 
Piper Aircraft, Inc., 2926 Piper Drive, Vero Beach, Florida 32960; 
telephone: (772) 567-4361; fax: (772) 978-6573; Internet: http://www.newpiper.com/company/publications.asp. You may review copies of the 
referenced service information at the FAA, Small Airplane Directorate, 
901 Locust St., Kansas City, Missouri 64106. For information on the 
availability of this material at the FAA, call (816) 329-4148.

Examining the AD Docket

    You may examine the AD docket 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 AD docket contains this proposed AD, the regulatory 
evaluation, any comments received, and other information. The street 
address for the Docket Office (phone: 800-647-5527) is in the ADDRESSES 
section. Comments will be available in the AD docket shortly after 
receipt.

FOR FURTHER INFORMATION CONTACT: Gregory K. Noles, Aerospace Engineer, 
FAA, Atlanta Aircraft Certification Office, 1701 Columbia Avenue, 
College Park, Georgia 30337; phone: (404) 474-5551; fax: (404) 474-
5606; e-mail: gregory.noles@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2011-0639; 
Directorate Identifier 2011-CE-016-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD because 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 about this proposed AD.

Discussion

    We issued Special Airworthiness Information Bulletin (SAIB) CE-04-
88, dated September 15, 2004. This SAIB alerted owners and operators of 
Piper Aircraft, Inc. (Piper) Models PA-23, PA-24, PA-30, and PA-39 
airplanes of potential corrosion of the stabilator torque tube, attach 
fittings, and attaching fasteners and recommended inspections of these 
parts. Based on the information available at issuance of this SAIB, the 
FAA had determined that an unsafe condition did not exist under 14 CFR 
part 39.
    After reviewing service data for corrosion on the stabilator torque 
tubes, Piper issued Piper Service Bulletin No. 1160, dated December 26, 
2005. This service information is for stabilator torque tube assembly 
inspection. We then received reports of cracks found in the stabilator 
horn, part number (P/N) 20397-00, during maintenance inspections per 
SAIB CE-04-88 or Service Bulletin 1160.
    With FAA assistance, the National Institute for Aviation Research 
(NIAR) investigated and concluded the root cause of the stabilator horn 
cracking was stress corrosion.
    We found two service difficulty reports for this safety issue. In 
parallel, the International Comanche Society (ICS) surveyed operators 
and provided additional service data. The ICS survey included 
approximately 80 targeted inspections and found 18 incidences of 
stabilator horn cracking, with all incidences occurring on Models PA-24 
and PA-24-250 airplanes. The same configuration of horn and torque 
assembly exists on Model PA-24-260 airplanes.
    This condition, if not corrected, could result in failure of the 
stabilator horn. Consequently, failure of the stabilator horn could 
lead to a loss of pitch control in flight.

Relevant Service Information

    We reviewed Piper Aircraft, Inc. Service Bulletin No. 1189, dated 
April 29, 2010. The service information describes procedures for 
stabilator horn assembly inspection.

FAA's Determination

    We are proposing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the same type design.

Proposed AD Requirements

    This proposed AD would require either replacement of the stabilator 
horn assembly or repetitive inspection of the stabilator horn assembly 
for corrosion or cracks with replacement of the stabilator horn 
assembly if any corrosion or cracks are found.

Differences Between the Proposed AD and the Service Information

    The service information requires an initial inspection of the 
stabilator horn assembly upon reaching the initial 1,000 hours time-in-
service (TIS), with a repetitive inspection every 100 hours TIS 
thereafter. After installation of a new stabilator horn assembly, the 
inspection cycle starts over with an initial inspection at 1,000 hours 
TIS since the new stabilator horn assembly was installed with the 100-
hour TIS repetitive inspections thereafter.
    This proposed AD requires either one of the following options: (1) 
An initial inspection of the stabilator horn assembly upon reaching 
1,000 hours TIS or within 100 hours TIS after the effective date of the 
AD, whichever occurs later, with repetitive inspections every 500 hours 
TIS or 3 years, whichever occurs first; or (2) replacement of the 
stabilator horn assembly upon reaching 1,000 hours TIS or within the 
next 100 hours TIS after the effective date of this AD, whichever 
occurs later. After replacement of the stabilator horn assembly, within 
1,000 hours TIS or 10 years, whichever occurs first, the stabilator 
horn assembly must be replaced or be initially inspected and start the 
inspection cycle in option 1.
    The service information applies to Piper Models PA-24, PA-24-250, 
PA-24-260, PA-24-400, PA-30, and PA-39 airplanes. We only have service 
history on Models PA-24 and PA-24-250 airplanes.
    While there is no service history of this unsafe condition on Model 
PA-24-260 airplanes, we are including it in the AD because it is an 
identical configuration to Models PA-24 and PA-24-250 airplanes for the 
horn and torque tube.
    There is no service history of this unsafe condition on the Models 
PA-24-400, PA-30, and PA-39 airplanes, including inspections from the 
ICS operator survey. Also, these models have a thicker torque tube, 
which reduces clamp-up forces; clamp-up forces are a key factor of the 
stress corrosion cracking. Therefore, we are not including the Models 
PA-24-400,

[[Page 36397]]

PA-30, and PA-39 airplanes in the applicability of this AD.

Costs of Compliance

    We estimate that this proposed AD affects 3,100 airplanes of U.S 
registry.
    We estimate the following costs to comply with this proposed AD:

                                                 Estimated costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
            Action                    Labor cost               Parts cost             product        operators
----------------------------------------------------------------------------------------------------------------
Stabilator horn assembly        12 work-hours x $85     Not applicable..........          $1,020      $3,162,000
 inspection.                     per hour = $1,020.
----------------------------------------------------------------------------------------------------------------

     We estimate the following costs to do any necessary replacements 
that would be required based on the results of the proposed inspection. 
We have no way of determining the number of airplanes that might need 
this replacement:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                   Action                                 Labor cost                Parts cost        product
----------------------------------------------------------------------------------------------------------------
Stabilator horn assembly replacement.......  12 work-hours x $85 per hour =                 $572          $1,592
                                              $1,020.
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     According to the manufacturer, some of the costs of this proposed 
AD may be covered under warranty, thereby reducing the cost impact on 
affected individuals. We do not control warranty coverage for affected 
individuals. As a result, we have included all costs in our cost 
estimate.

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 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 this 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),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) 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.

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 39--AIRWORTHINESS 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 
airworthiness directive (AD):

Piper Aircraft, Inc.: Docket No. FAA-2011-0639, Directorate 
Identifier 2011-CE-016-AD.

Comments Due Date

    (a) We must receive comments by August 8, 2011.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to the following Piper Aircraft, Inc. 
airplanes, certificated in any category:
    (1) Model PA-24, serial numbers (SNs) 24-1 through 24-3687;
    (2) Model PA-24-250, SNs 24-1, 24-103 through 24-3687; and
    (3) Model PA-24-260, SNs 24-3642 and 24-4000 through 24-5034.

Subject

    (d) Joint Aircraft System Component (JASC)/Air Transport 
Association (ATA) of America Code 27: Flight Controls.

Unsafe Condition

    (e) This AD was prompted by reports of cracks developing in the 
stabilator horn assembly. We are issuing this AD to detect and 
correct corrosion or cracks in the stabilator horn assembly. 
Corrosion or cracks could lead to failure of the stabilator horn. 
Consequently, failure of the stabilator horn could lead to a loss of 
pitch control in flight.

Compliance

    (f) Comply with this AD following Piper Aircraft, Inc. Service 
Bulletin No. 1189, dated April 29, 2010, within the compliance times 
specified in this AD, unless already done (does not eliminate the 
repetitive actions of this AD).

Inspection/Replacement

    (g) When the stabilator horn assembly reaches a total of 1,000 
hours time-in-service (TIS) or within the next 100 hours TIS after 
the effective date of this AD, whichever occurs later, do either of 
the following actions:
    (1) Initially inspect the stabilator horn assembly for corrosion 
or cracks. Repetitively thereafter inspect at intervals not to 
exceed 500 hours TIS or 3 years, whichever occurs first; or
    (2) Replace the stabilator horn assembly with a new stabilator 
horn assembly. Repetitively thereafter replace the stabilator horn 
assembly with a new stabilator horn assembly within the next 1,000 
hours TIS

[[Page 36398]]

after the last replacement or within the next 10 years after the 
last replacement, whichever occurs first.
    (h) If any corrosion or cracks are found during any of the 
inspections required in paragraph (g)(1) of this AD, before further 
flight, you must replace the stabilator horn assembly with a new 
stabilator horn assembly. After the new stabilator horn assembly 
reaches a total of 1,000 hours TIS or within the next 10 years after 
the last replacement, whichever occurs first, you must do either of 
the actions required in paragraphs (g)(1) or (g)(2) of this AD.
    (i) You may at any time replace the stabilator horn assembly 
with a new stabilator horn assembly, provided no corrosion or cracks 
were found during an inspection that would require replacement 
before further flight. After the new stabilator horn assembly 
reaches a total of 1,000 hours TIS or within the next 10 years after 
the last replacement, whichever occurs first, you must do either of 
the actions required in paragraphs (g)(1) or (g)(2) of this AD.
    (j) If you replace the stabilator horn assembly as specified in 
paragraph (g)(2) of this AD, after the new stabilator horn assembly 
reaches a total of 1,000 hours TIS or within the next 10 years after 
the last replacement, whichever occurs first, you may begin the 
inspection requirements of paragraph (g)(1) instead of the 
repetitive replacement requirements of paragraph (g)(2).

    Note:  Piper Aircraft, Inc. Service Bulletin No. 1160, dated 
December 26, 2005; Special Airworthiness Information Bulletin CE-04-
88, dated September 15, 2004; and AD 74-13-03, Amendment 39-2588 (41 
FR 17371, April 26, 1976) are related to this AD action. For the 
attached torque tube, you may consider combining that inspection 
with the requirements of this AD.

Special Flight Permit

    (k) Special flight permits are permitted with the following 
limitation: flight with known cracks is prohibited.

Alternative Methods of Compliance (AMOCs)

    (l)(1) 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. In accordance with 14 
CFR 39.19, send your request to your principal inspector or local 
Flight Standards District Office, as appropriate. If sending 
information directly to the manager of the ACO, send it to the 
attention of the person identified in the Related Information 
section of this AD.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.

Related Information

    (m) For more information about this AD, contact Gregory K. 
Noles, Aerospace Engineer, FAA, Atlanta ACO, 1701 Columbia Avenue, 
College Park, Georgia 30337; phone: (404) 474-5551; fax: (404) 474-
5606; e-mail: gregory.noles@faa.gov.
    (n) For service information identified in this AD, contact Piper 
Aircraft, Inc., 2926 Piper Drive, Vero Beach, Florida 32960; 
telephone: (772) 567-4361; fax: (772) 978-6573; Internet: http://www.newpiper.com/company/publications.asp. You may review copies of 
the referenced service information at the FAA, Small Airplane 
Directorate, 901 Locust St., Kansas City, Missouri 64106. For 
information on the availability of this material at the FAA, call 
(816) 329-4148.

    Issued in Kansas City, Missouri on June 16, 2011.
John Colomy,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-15543 Filed 6-21-11; 8:45 am]
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