Federal Register, Volume 75 Issue 194 (Thursday, October 7, 2010)

[Federal Register Volume 75, Number 194 (Thursday, October 7, 2010)]
[Proposed Rules]
[Pages 62005-62008]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-25289]

[[Page 62005]]

-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2009-0622; Directorate Identifier 2009-CE-034-AD]
RIN 2120-AA64

Airworthiness Directives; Pilatus Aircraft Ltd. 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

AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: We propose to adopt a new airworthiness directive (AD) for the
products listed above that would revise an existing AD. 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:

Findings of corrosion, wear and cracks in the upper wing strut
fittings on some PC-6 aircraft have been reported in the past. 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, wear and/or corrosion in this area could cause failure of
the upper attachment fitting, leading to failure of the wing
structure and subsequent loss of control of the aircraft.
To address this problem, FOCA published AD TM-L Nr. 80.627-6/
Index 72-2 and HB-2006-400 and EASA published AD 2007-0114 to
require specific inspections and to obtain a fleet status. Since the
issuance of AD 2007-0114, the reported data proved that it was
necessary to establish and require repetitive inspections.
EASA published Emergency AD 2007-0241-E to extend the
applicability and to require repetitive eddy current and visual
inspections of the upper wing strut fitting for evidence of cracks,
wear and/or corrosion and examination of the spherical bearing and
replacement of cracked fittings. Collected data received in response
to Emergency AD 2007-0241-E resulted in the issuance of EASA AD
2007-0241R1 that permitted extending the intervals for the
repetitive eddy current and visual inspections from 100 Flight Hours
(FH) to 300 FH and from 150 Flight Cycles (FC) to 450 FC,
respectively. In addition, oversize bolts were introduced by Pilatus
PC-6 Service Bulletin (SB) 57-005 R1 and the fitting replacement
procedure was adjusted accordingly.
Based on fatigue test results, EASA AD 2007-0241R2 was issued to
extend the repetitive inspection interval to 1100 FH or 12 calendar
months, whichever occurs first, and to delete the related flight
cycle intervals and the requirement for the ``Mild Corrosion
Severity Zone''. In addition, some editorial changes have been made
for reasons of standardization and readability.
Revision 3 of this AD referred to the latest revision of the PC-
6 Aircraft Maintenance Manual (AMM) Chapter 5 limitations which have
included the same repetitive inspection intervals and procedures
already mandated in the revision 2 of AD 2007-0241. Besides the
inspections, in the latest revision of the PC-6 AMM, the replacement
procedures for the fittings were included.
Additionally, EASA AD 2007-0241R3 introduced the possibility to
replace the wing strut fitting with a new designed wing strut
fitting. With this optional part replacement, in the repetitive
inspection procedure the 1100 FH interval is deleted so that only
calendar defined intervals of inspections remained applicable.

DATES: We must receive comments on this proposed AD by November 22,
2010.

ADDRESSES: You may send comments by any of the following methods:
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: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays.

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 (telephone (800) 647-5527) 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:

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-2009-0622;
Directorate Identifier 2009-CE-034-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://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

On August 18, 2009, we issued AD 2009-18-03, Amendment 39-15999 (74
FR 43636; August 27, 2009). That AD required actions intended to
address an unsafe condition on the products listed above.
Since we issued AD 2009-18-03, Pilatus has updated their
maintenance programs with new requirements and limitations. Another
proposed AD action, Docket No. FAA-2010-1011, will require the
incorporation of the updated maintenance requirements into the
airworthiness limitations section of the instructions for continued
airworthiness. Those updated maintenance requirements will include the
repetitive inspections for the wing strut fittings and the spherical
bearings currently included in AD 2009-18-03.
The European Aviation Safety Agency (EASA), which is the Technical
Agent for the Member States of the European Community, has issued EASA
AD No.: 2007-0241R4, dated August 31, 2010 (referred to after this as
``the MCAI''), to correct an unsafe condition for the specified
products. The MCAI states:

[[Page 62006]]

obtain a fleet status. Since the issuance of AD 2007-0114, the
reported data proved that it was necessary to establish and require
repetitive inspections.
EASA published Emergency AD 2007-0241-E to extend the
applicability and to require repetitive eddy current and visual
inspections of the upper wing strut fitting for evidence of cracks,
wear and/or corrosion and examination of the spherical bearing and
replacement of cracked fittings. Collected data received in response
to Emergency AD 2007-0241-E resulted in the issuance of EASA AD
2007-0241R1 that permitted extending the intervals for the
repetitive eddy current and visual inspections from 100 Flight Hours
(FH) to 300 FH and from 150 Flight Cycles (FC) to 450 FC,
respectively. In addition, oversize bolts were introduced by Pilatus
PC-6 Service Bulletin (SB) 57-005 R1 and the fitting replacement
procedure was adjusted accordingly.
Based on fatigue test results, EASA AD 2007-0241R2 was issued to
extend the repetitive inspection interval to 1100 FH or 12 calendar
months, whichever occurs first, and to delete the related flight
cycle intervals and the requirement for the ``Mild Corrosion
Severity Zone''. In addition, some editorial changes have been made
for reasons of standardization and readability.
Revision 3 of this AD referred to the latest revision of the PC-
6 Aircraft Maintenance Manual (AMM) Chapter 5 limitations which have
included the same repetitive inspection intervals and procedures
already mandated in the revision 2 of AD 2007-0241. Besides the
inspections, in the latest revision of the PC-6 AMM, the replacement
procedures for the fittings were included.
Additionally, EASA AD 2007-0241R3 introduced the possibility to
replace the wing strut fitting with a new designed wing strut
fitting. With this optional part replacement, in the repetitive
inspection procedure the 1100 FH interval is deleted so that only
calendar defined intervals of inspections remained applicable.
The aim of this new revision is to only mandate the initial
inspection requirement and consequently to limit its applicability
to aeroplanes which are not already in compliance with EASA AD 2007-
0241R3. All aeroplanes which are in compliance with EASA AD 2007-
0241R3 have to follow the repetitive inspection requirements as
described in Pilatus PC-6 AMM Chapter 04-00-00, Document Number
01975, Revision 12 and the Airworthiness Limitations (ALS) Document
Number 02334 Revision 1 mandated by EASA AD 2010-0176. Therefore the
repetitive inspection requirements corresponding paragraphs have
been deleted in this new EASA AD revision. The paragraph numbers of
EASA AD 2007-0241R numbering has been maintained for referencing
needs.

The proposed AD would require actions that are intended to address the
unsafe condition described in the MCAI. You may obtain further
information by examining the MCAI in the AD docket.

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

We estimate that this proposed AD will affect 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 $85 per work-hour.
Based on these figures, we estimate the cost of the proposed AD on
U.S. operators to be $29,750, or $595 per product.
In addition, we estimate that any necessary follow-on actions would
take about 30 work-hours and require parts costing $5,000, for a cost
of $7,550 per product. 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, 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 removing Amendment 39-15999 (74 FR
43636; August 27, 2009), and adding the following new AD:

Pilatus Aircraft Ltd.: Docket No. FAA-2009-0622; Directorate
Identifier 2009-CE-034-AD.

[[Page 62007]]

Comments Due Date

(a) We must receive comments by November 22, 2010.

Affected ADs

(b) This AD revises AD 2009-18-03, Amendment 39-15999.

Applicability

(c) This AD applies to Pilatus Aircraft Ltd. 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, all manufacturer serial number (MSN), and
MSN 2001 through 2092, 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:
Findings of corrosion, wear and cracks in the upper wing strut
fittings on some PC-6 aircraft have been reported in the past. 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, wear and/or corrosion in this area could cause failure of
the upper attachment fitting, leading to failure of the wing
structure and subsequent loss of control of the aircraft.
To address this problem, FOCA published AD TM-L Nr. 80.627-6/
Index 72-2 and HB-2006-400 and EASA published AD 2007-0114 to
require specific inspections and to obtain a fleet status. Since the
issuance of AD 2007-0114, the reported data proved that it was
necessary to establish and require repetitive inspections.
EASA published Emergency AD 2007-0241-E to extend the
applicability and to require repetitive eddy current and visual
inspections of the upper wing strut fitting for evidence of cracks,
wear and/or corrosion and examination of the spherical bearing and
replacement of cracked fittings. Collected data received in response
to Emergency AD 2007-0241-E resulted in the issuance of EASA AD
2007-0241R1 that permitted extending the intervals for the
repetitive eddy current and visual inspections from 100 Flight Hours
(FH) to 300 FH and from 150 Flight Cycles (FC) to 450 FC,
respectively. In addition, oversize bolts were introduced by Pilatus
PC-6 Service Bulletin (SB) 57-005 R1 and the fitting replacement
procedure was adjusted accordingly.
Based on fatigue test results, EASA AD 2007-0241R2 was issued to
extend the repetitive inspection interval to 1100 FH or 12 calendar
months, whichever occurs first, and to delete the related flight
cycle intervals and the requirement for the ``Mild Corrosion
Severity Zone''. In addition, some editorial changes have been made
for reasons of standardization and readability.
Revision 3 of this AD referred to the latest revision of the PC-
6 Aircraft Maintenance Manual (AMM) Chapter 5 limitations which have
included the same repetitive inspection intervals and procedures
already mandated in the revision 2 of AD 2007-0241. Besides the
inspections, in the latest revision of the PC-6 AMM, the replacement
procedures for the fittings were included.
Additionally, EASA AD 2007-0241R3 introduced the possibility to
replace the wing strut fitting with a new designed wing strut
fitting. With this optional part replacement, in the repetitive
inspection procedure the 1100 FH interval is deleted so that only
calendar defined intervals of inspections remained applicable.
The aim of this new revision is to only mandate the initial
inspection requirement and consequently to limit its applicability
to aeroplanes which are not already in compliance with EASA AD 2007-
0241R3. All aeroplanes which are in compliance with EASA AD 2007-
0241R3 have to follow the repetitive inspection requirements as
described in Pilatus PC-6 AMM Chapter 04-00-00, Document Number
01975, Revision 12 and the Airworthiness Limitations (ALS) Document
Number 02334 Revision 1 mandated by EASA AD 2010-0176. Therefore the
repetitive inspection requirements corresponding paragraphs have
been deleted in this new EASA AD revision. The paragraph numbers of
EASA AD 2007-0241R numbering has been maintained for referencing
needs.
The proposed AD would require actions that are intended to address
the unsafe condition described in the MCAI.

Actions and Compliance

(f) Unless already done, do the following actions:
(1) For airplanes that have not had both wing strut fittings
replaced within the last 100 hours time-in-service (TIS) before
September 26, 2007 (the effective date of AD 2007-19-14), or have
not been inspected using an eddy current inspection method following
Pilatus Aircraft Ltd. Pilatus PC-6 Service Bulletin No. 57-004,
dated April 16, 2007, within the last 100 hours TIS before September
26, 2007 (the effective date of AD 2007-19-14): Before further
flight after either September 26, 2007 (the effective date of AD
2007-19-14), or October 1, 2009 (the effective date of AD 2009-18-
03), visually inspect the upper wing strut fittings and examine the
spherical bearings following the Pilatus Aircraft Ltd. Pilatus PC-6
Service Bulletin No. 57-005, REV No. 2, dated May 19, 2008.
(2) For all airplanes: Within 25 hours TIS after September 26,
2007 (the effective date of AD 2007-19-14), or within 30 days after
September 26, 2007 (the effective date of AD 2007-19-14), whichever
occurs first, visually and using eddy current methods, inspect the
upper wing strut fittings and examine the spherical bearings
following Pilatus Aircraft Ltd. Pilatus PC-6 Service Bulletin No.
57-005, REV No. 2, dated May 19, 2008.
(3) You may also take ``unless already done'' credit for any
inspection specified in paragraphs (f)(1) or (f)(2) of this AD if
done before October 1, 2009 (the effective date retained from AD
2009-18-03) following Pilatus Aircraft Ltd. Pilatus PC-6 Service
Bulletin No. 57-005, dated August 30, 2007; or Pilatus Aircraft Ltd.
Pilatus PC-6 Service Bulletin No. 57-005, REV No. 1, dated November
19, 2007.
(4) For all airplanes: If during any inspection required by
paragraphs (f)(1) or (f)(2) of this AD you find cracks in the upper
wing strut fitting or the spherical bearing is not in conformity,
before further flight, replace the cracked upper wing strut fitting
and/or the nonconforming spherical bearing following Chapter 57-00-
02 of Pilatus Aircraft Ltd. Pilatus PC-6 Aircraft Maintenance
Manual, dated November 30, 2008.

Note 1: Another proposed AD action, Docket No. FAA-2010-1011,
proposes to require the incorporation of the updated maintenance
requirements into the airworthiness limitations section of the
instructions for continued airworthiness. Those updated maintenance
requirements include the repetitive inspections for the wing strut
fittings and the spherical bearings currently included in AD 2009-
18-03.

FAA AD Differences

Note 2: This AD differs from the MCAI and/or service information
as follows: No differences.

Other FAA AD Provisions

(g) The following provisions also apply to this AD:
(1) Alternative Methods of Compliance (AMOCs): The Manager,
Standards Office, 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 EASA AD No.: 2007-0241R4, dated August 31,
2010; Pilatus Aircraft Ltd. Pilatus PC-6 Service Bulletin No. 57-
005, REV No. 2, dated May 19, 2008;

[[Page 62008]]

Pilatus Aircraft Ltd. Pilatus PC-6 Service Bulletin No. 57-005, REV
No. 1, dated November 19, 2007; Pilatus Aircraft Ltd. Pilatus PC-6
Service Bulletin No. 57-005, dated August 30, 2007; Pilatus Aircraft
Ltd. Pilatus PC-6 Service Bulletin No. 57-004, dated April 16, 2007;
and Chapter 57-00-02 of Pilatus Aircraft Ltd. Pilatus PC-6 Aircraft
Maintenance Manual, dated November 30, 2008, for related
information.

Issued in Kansas City, Missouri, on September 30, 2010.
John Colomy,
Acting Manager, Small Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2010-25289 Filed 10-6-10; 8:45 am]
BILLING CODE 4910-13-P