[Federal Register Volume 72, Number 103 (Wednesday, May 30, 2007)]
[Proposed Rules]
[Pages 29895-29897]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-10315]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
 ========================================================================
 

  Federal Register / Vol. 72, No. 103 / Wednesday, May 30, 2007 / 
Proposed Rules  

[[Page 29895]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-28157; Directorate Identifier 2007-CE-046-AD]
RIN 2120-AA64


Airworthiness Directives; Pilatus Aircraft Ltd. Model 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) originated 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:

    This Airworthiness Directive (AD) is prompted due to the 
discovery of cracks in the upper wing strut fittings of some PC-6 
aircraft.
    It is possible that the spherical bearing of the wing strut 
fittings installed in the underwing can be loose in the fitting or 
cannot rotate because of corrosion. In this condition, the joint 
cannot function as designed and fatigue cracks may then develop. 
Undetected cracks in this area could lead to failure of upper 
attachment fitting. This could result in the failure of the wing 
structure with 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 June 29, 2007.

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: Go to 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 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, 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. This 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.
    This proposed AD references the MCAI and related service 
information that we considered in forming the engineering basis to 
correct the unsafe condition. The proposed AD contains text copied from 
the MCAI and for this reason might not follow our plain language 
principles.

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-2007-
28157; Directorate Identifier 2007-CE-046-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 European Aviation Safety Agency (EASA), which is the Technical 
Agent for the Member States of the European Community, has issued AD 
No: 2007-0114, dated May 2, 2007 (referred to after this as ``the 
MCAI''), to correct an unsafe condition for the specified products. The 
MCAI states:

    This Airworthiness Directive (AD) is prompted due to the 
discovery of cracks in the upper wing strut fittings of some PC-6 
aircraft.
    It is possible that the spherical bearing of the wing strut 
fittings installed in the underwing can be loose in the fitting or 
cannot rotate because of corrosion. In this condition, the joint 
cannot function as designed and fatigue cracks may then develop. 
Undetected cracks in this area could lead to failure of upper 
attachment fitting. This could result in the failure of the wing 
structure with subsequent loss of control of the airplane. In order 
to correct and monitor this situation, the present AD mandates a 
one-time inspection of the wing strut fittings and replacement of 
damaged wing strut fittings with new ones. This AD also requires 
examination of the spherical bearings installed in the wing strut 
fittings and their replacement for bearings that do not pass the 
examination criteria.

You may obtain further information by examining the MCAI in the AD 
docket.

Relevant Service Information

    Pilatus Aircraft Ltd. has issued Service Bulletin No. 57-004, dated 
April 16, 2007. The actions described in this service information are 
intended to

[[Page 29896]]

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 
highlighted in a NOTE within the proposed AD.

Costs of Compliance

    Based on the service information, we estimate that this proposed AD 
would affect about 50 products of U.S. registry. We also estimate that 
it would take about 7 work-hours per product to comply with the basic 
requirements of this proposed AD. The average labor rate is $80 per 
work-hour.
    Based on these figures, we estimate the cost of the proposed AD on 
U.S. operators to be $28,000, or $560 per product.
    In addition, we estimate that any necessary follow-on actions would 
take about 15 work-hours and require parts costing $2,500 for a cost of 
$3,700 per fitting or $7,400 per product if both fittings are replaced. 
We have no way of determining the number of products that may need 
these actions.

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.

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.: Docket No. FAA-2007-28157; Directorate 
Identifier 2007-CE-046-AD.

Comments Due Date

    (a) We must receive comments by June 29, 2007.

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 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.

Subject

    (d) Air Transport Association of America (ATA) Code 57: Wings.

Reason

    (e) The mandatory continuing airworthiness information (MCAI) 
states:

    This Airworthiness Directive (AD) is prompted due to the 
discovery of cracks in the upper wing strut fittings of some PC-6 
aircraft.
    It is possible that the spherical bearing of the wing strut 
fittings installed in the underwing can be loose in the fitting or 
cannot rotate because of corrosion. In this condition, the joint 
cannot function as designed and fatigue cracks may then develop. 
Undetected cracks in this area could lead to failure of upper 
attachment fitting. This could result in the failure of the wing 
structure with subsequent loss of control of the airplane.
    In order to correct and monitor this situation, the present AD 
mandates a one time inspection of the wing strut fittings and 
replacement of damaged wing strut fittings with new ones. This AD 
also requires examination of the spherical bearings installed in the 
wing strut fittings and their replacement for bearings that do not 
pass the examination criteria.

Actions and Compliance

    (f) Unless already done, do the following actions:
    (1) For MSN 2001 through MSN 2092: Within the next 100 hours 
time-in-service (TIS) on the upper wing strut fitting after the 
effective date of this AD or within 3 months after the effective 
date of this AD, whichever occurs first, and repetitively thereafter 
at intervals not to exceed 12 months, do the actions specified in 
paragraph (f)(3) of this AD.
    (2) For MSN 101 through MSN 951 do the following actions, as 
applicable:
    (i) If the upper wing strut fitting has less than 3,500 hours 
TIS or has been installed for less than 84 months (7 years): Within 
the next 1,000 hours TIS on the upper wing strut fitting after the 
effective date of this AD or within 24 months after the effective 
date of this AD without exceeding 3,600 hours TIS

[[Page 29897]]

or 87 months (7 years, 3 months), whichever occurs first, and 
repetitively thereafter at intervals not to exceed 12 months, do the 
actions specified in paragraph (f)(3) of this AD, or;
    (ii) If the upper wing strut fitting has 3,500 or more hours TIS 
or has been installed for 84 months (7 years) or longer: Within the 
next 100 hours TIS on the upper wing strut fitting after the 
effective date of this AD or within 3 months after the effective 
date of this AD, whichever occurs first, and repetitively thereafter 
at intervals not to exceed 12 months, do the actions specified in 
paragraph (f)(3) of this AD.

    Note 1: If the TIS of the upper wing strut fittings cannot be 
positively determined by a review in the airplane maintenance 
records, then by default the upper wing strut fittings were 
installed from the date of original Certificate of Airworthiness.

    (3) Do the following at the times specified in paragraph (f)(1) 
or (f)(2) of this AD:
    (i) Perform a visual and non-destructive inspection of the upper 
wing strut fittings for cracks following the Accomplishment 
Instructions in Pilatus Aircraft Ltd. Service Bulletin No. 57-004, 
dated April 16, 2007.
    (ii) Examine for conformity the spherical bearings following the 
Accomplishment Instructions in Pilatus Aircraft Ltd. Service 
Bulletin No. 57-004, dated April 16, 2007.
    (4) If during any inspection required by paragraph (f)(3)(i) of 
this AD, cracks are found in the upper wing strut fitting, before 
further flight replace the wing strut fitting with a new part number 
(P/N) 111.35.06.185 (left side) or P/N 111.35.06.186 (right side) 
following the Accomplishment Instructions in Pilatus Aircraft Ltd. 
Service Bulletin No. 57-004, dated April 16, 2007. Replacement of 
the upper wing strut fitting does not terminate the repetitive 
inspection specified in paragraph (f)(3) of this AD.
    (5) If during any inspection required by paragraph (f)(3)(ii) of 
this AD, the spherical bearing is found not in conformity, replace 
the bearing with a new P/N 944.61.00.109 following the 
Accomplishment Instructions in Pilatus Aircraft Ltd. Service 
Bulletin No. 57-004, dated April 16, 2007. Replacement of the 
spherical bearing does not terminate the repetitive inspection 
specified in paragraph (f)(3) of this AD.
    (6) Report to Pilatus Aircraft Ltd. Customer Liaison Manager 
results of the inspection/examination using Table 1 of Pilatus 
Aircraft Ltd. Service Bulletin No. 57-004, dated April 16, 2007.

FAA AD Differences

    Note 2: This AD differs from the MCAI and/or service information 
as follows:
    (1) The FAA AD is requiring repetitive inspections and reporting 
results to the manufacturer, not just a one-time inspection and 
report as required in the MCAI.
    (2) The Service Bulletin specifies ``subsequent inspections for 
cracks 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

    (g) The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, 
Standards Staff, FAA, has the authority to approve AMOCs for this 
AD, if requested using the procedures found in 14 CFR 39.19. Send 
information to ATTN: Doug Rudolph, Aerospace Engineer, FAA, Small 
Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 
64106; telephone: (816) 329-4059; fax: (816) 329-4090. Before using 
any approved AMOC on any airplane to which the AMOC applies, notify 
your appropriate principal inspector (PI) in the FAA Flight 
Standards District Office (FSDO), or lacking a PI, your local FSDO.
    (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

    (h) Refer to MCAI European Aviation Safety Agency (EASA) AD No: 
2007-0114, dated May 02, 2007; and Pilatus Aircraft Ltd. Service 
Bulletin No. 57-004, dated April 16, 2007, for related information.

    Issued in Kansas City, Missouri, on May 23, 2007.
David R. Showers,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E7-10315 Filed 5-29-07; 8:45 am]
BILLING CODE 4910-13-P