[Federal Register Volume 71, Number 213 (Friday, November 3, 2006)]
[Proposed Rules]
[Pages 64653-64655]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-18574]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-25929; Directorate Identifier 2006-CE-54-AD]
RIN 2120-AA64


Airworthiness Directives; Pilatus Aircraft Ltd., PC-6 Series 
Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (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 results from mandatory 
continuing airworthiness information (MCAI) issued by an aviation 
authority of another country to identify and correct an unsafe 
condition on an aviation product. The MCAI describes the unsafe 
condition as the discovery of exfoliation corrosion in the fittings of 
some PC-6 airplanes. These fittings are installed exterior to the 
bottom skin of the wing skin. If not corrected, undetected corrosion in 
this area could lead to failure of the fitting and subsequent loss of 
control of the airplane. The proposed AD would require actions that are 
intended to address the unsafe condition described in the MCAI.

DATES: We must receive comments on this proposed AD by December 4, 
2006.

ADDRESSES: You may send comments by any of the following methods:
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Fax: (202) 493-2251.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590-0001.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
     Federal eRulemaking Portal: http://www.regulations.gov. 
Follow the instructions for submitting comments.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://dms.dot.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

[[Page 64654]]

proposed AD, the regulatory evaluation, any comments received, and 
other information. The street address for the Docket Office (telephone 
(800) 647-5227) is in the ADDRESSES section. Comments will be available 
in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Doug Rudolph, Aerospace Engineer, FAA, 
Small Airplane Directorate, 901 Locust Street, Room 301, Kansas City, 
Missouri 64106; telephone: (816) 329-4059; fax: (816) 329-4090.

SUPPLEMENTARY INFORMATION:

Streamlined Issuance of AD

    The FAA is implementing a new process for streamlining the issuance 
of ADs related to MCAI. The streamlined process will allow us to adopt 
MCAI safety requirements in a more efficient manner and will reduce 
safety risks to the public. This process continues to follow all FAA AD 
issuance processes to meet legal, economic, Administrative Procedure 
Act, and Federal Register requirements. We also continue to meet our 
technical decision-making responsibilities to identify and correct 
unsafe conditions on U.S.-certificated products.

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include ``Docket No. FAA-2006-
25929; Directorate Identifier 2006-CE-54-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://dms.dot.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

    The Federal Office for Civil Aviation (FOCA), which is the 
airworthiness authority for Switzerland, has issued FOCA AD HB-2006-
400, effective date September 28, 2006 (referred to after this as ``the 
MCAI''), to correct an unsafe condition for the specified products. The 
MCAI states the FOCA AD was prompted due to the discovery of 
exfoliation corrosion in the fittings of some PC-6 airplanes. These 
fittings are installed exterior to the bottom skin of the wing skin. If 
not corrected, undetected corrosion in this area could lead to failure 
of the fitting and subsequent loss of control of the airplane. In order 
to correct and control the situation, the MCAI requires a one time 
inspection of the wing strut fitting and the replacement of corroded 
wing strut fittings with new retrofit wing strut fittings. You may 
obtain further information by examining the MCAI in the AD docket.

Relevant Service Information

    Pilatus Aircraft Ltd., has issued Service Bulletin No. 57-003, 
dated June 13, 2006. The actions described in this service information 
are intended to correct the unsafe condition identified in the MCAI.

FAA's Determination and Requirements of the Proposed AD

    This product has been approved by the aviation authority of another 
country, and is approved for operation in the United States. Pursuant 
to our bilateral agreement with this State of Design Authority, they 
have notified us of the unsafe condition described in the MCAI and 
service information referenced above. We are proposing this AD because 
we evaluated all information and determined the unsafe condition exists 
and is likely to exist or develop on other products of the same type 
design.

Differences Between This Proposed AD and the MCAI or Service 
Information

    We have reviewed the MCAI and related service information and, in 
general, agree with their substance. But we might have found it 
necessary to use different words from those in the MCAI to ensure the 
AD is clear for U.S. operators and is enforceable. In making these 
changes, we do not intend to differ substantively from the information 
provided in the MCAI and related service information.
    We might also have proposed different actions in this AD from those 
in the MCAI in order to follow FAA policies. Any such differences are 
described in a separate paragraph of the proposed AD. These 
requirements, if ultimately adopted, will take precedence over the 
actions copied from the MCAI.

Costs of Compliance

    Based on the service information, we estimate that this proposed AD 
would affect about 49 products of U.S. registry. We also estimate that 
it would take about 27 work-hours per product to comply with the 
proposed AD. The average labor rate is $80 per work-hour. Required 
parts would cost about $2,500 per wing, or $5,000 per product. Where 
the service information lists required parts costs that are covered 
under warranty, we have assumed that there will be no charge for these 
costs. As we do not control warranty coverage for affected parties, 
some parties may incur costs higher than estimated here. Based on these 
figures, we estimate the cost of the proposed AD on U.S. operators to 
be $350,840, or $7,160 per product.

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); 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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

[[Page 64655]]

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 AD:

Pilatus Aircraft Ltd.: FAA-2006-25929; Directorate Identifier 2006-
CE-54-AD

Comments Due Date

    (a) We must receive comments by December 4, 2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Models PC-6, PC-6-H1, PC-6-H2, PC-6/350, 
PC-6/350-H1, PC-6/350-H2, PC-6/A, PC-6/A-H1, PC-6/A-H2, PC-6/B-H2, 
PC-6/B1-H2, PC-6/B2-H2, PC-6/B2-H4, PC-6/C-H2, and PC-6/C1-H2 
airplanes; manufacturer serial numbers (MSN) 101 through 949, MSN 
951, and MSN 2001 through 2092; that are certificated in any 
category. These airplanes are also identified as Fairchild Republic 
Company PC-6 airplanes, Fairchild Industries PC-6 airplanes, 
Fairchild Heli Porter PC-6 airplanes, or Fairchild-Hiller 
Corporation PC-6 airplanes.

Reason

    (d) The Switzerland Federal Office for Civil Aviation (FOCA) 
Airworthiness Directive (AD) was prompted due to the discovery of 
exfoliation corrosion in the fittings of some PC-6 airplanes. These 
fittings are installed exterior to the bottom skin of the wing skin. 
If not corrected, undetected corrosion in this area could lead to 
failure of the fitting and subsequent loss of control of the 
airplane.

Actions and Compliance

    (e) Unless already done, do the following actions.
    (1) Within 12 months after the effective date of this AD and 
repetitively thereafter not to exceed 12 months, perform an 
inspection required by paragraph 3.B.(2) of PILATUS PC-6 Service 
Bulletin (SB) No. 57-003, dated June 13, 2006, of the fittings Part 
Number (P/N) 6102.0041.00, P/N 111.35.06.055 or P/N 111.35.06.056 
for signs of corrosion. Minor surface corrosion is permitted 
according to the Repair and Overhaul Manual (ROM) (Report No. 1391), 
Chap. 2 and 4. Corrosion outside these limits is not permitted.
    (2) If during any of the inspections required by paragraph 
(e)(1) of this AD, any minor surface corrosion is found, prior to 
further flight, remove the minor surface corrosion (Ref. ROM. Chap. 
2 and 4).
    (3) If during any of the inspections required by paragraph 
(e)(1) of this AD, any corrosion out of limits is found (Ref. ROM, 
Chap. 2 and 4), prior to further flight, replace the fittings in 
accordance with paragraph 4. of PILATUS PC-6 SB No. 57-003, dated 
June 13, 2006, with new (retrofit) fittings P/N 111.35.06.185 and/or 
P/N 111.35.06.186.
    (4) Replacement of the fittings with new (improved) fittings P/N 
111.35.06.185 (left hand side) and/or 111.35.06.186 (right hand 
side) terminates the repetitive inspection for that side.

FAA AD Differences

    Note: This AD differs from the MCAI and/or service information 
as follows:
    (1) The FAA AD is requiring repetitive inspections, not just a 
one time inspection as required in the MCAI.
    (2) The Service Bulletin specifies ``subsequent inspection for 
corrosion will be included in chapter 5 of the Aircraft Maintenance 
Manual (AMM).'' The only way we (FAA) can mandate these repetitive 
inspections is through an AD.

Other FAA AD Provisions

    (f) The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, 
Standards Staff, FAA, Attn: Doug Rudolph, Aerospace Engineer, FAA, 
Small Airplane Directorate, 901 Locust, Room 301, Kansas City, 
Missouri 64106; telephone: (816) 329-4059; facsimile: (816) 329-
4090, has the authority to approve AMOCs for this AD, if requested 
using the procedures found in 14 CFR 39.19.
    (2) Airworthy Product: For any requirement in this AD to obtain 
corrective actions from a manufacturer or other source, use these 
actions if they are FAA-approved. Corrective actions are considered 
FAA-approved if they are approved by the State of Design Authority 
(or their delegated agent). You are required to assure the product 
is airworthy before it is returned to service.
    (3) Reporting Requirements: For any reporting requirement in 
this AD, under the provisions of the Paperwork Reduction Act (44 
U.S.C. 3501 et.seq.), the Office of Management and Budget (OMB) has 
approved the information collection requirements and has assigned 
OMB Control Number 2120-0056.

Related Information

    (g) This AD is related to FOCA AD HB-2006-400, effective date 
September 28, 2006, which references Pilatus Aircraft Ltd. SB No. 
57-003, dated June 13, 2006.

    Issued in Kansas City, Missouri, on October 27, 2006.
James E. Jackson,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E6-18574 Filed 11-2-06; 8:45 am]
BILLING CODE 4910-13-P