[Federal Register Volume 71, Number 78 (Monday, April 24, 2006)]
[Proposed Rules]
[Pages 20919-20922]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-6055]


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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-24094; Directorate Identifier 2006-CE-20-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 revise Airworthiness Directive (AD) 68-17-03, 
which applies to all Pilatus Aircraft Ltd. PC-6 series airplanes. AD 
68-17-03 currently requires you to repetitively inspect the rudder end 
rib for cracks and replace the rudder end rib with a modified rudder 
end rib when you find cracks. Installing the modified rudder end rib 
terminates the repetitive inspection requirements of AD 68-17-03. Under 
a licensing agreement with Pilatus, Fairchild Republic Company (also 
identified as Fairchild Industries, Fairchild Heli Porter, or 
Fairchild-Hiller Corporation) produced Model PC-6 series airplanes 
(manufacturer serial numbers 2001 through 2092) in the United States. 
AD 68-17-03 was intended to apply to all affected serial numbers of 
Model PC-6 series airplanes listed on Type Certificate Data Sheet 
(TCDS) No. 7A15, including the Fairchild-produced airplanes. 
Consequently, this proposed AD would clarify that all models of the PC-
6 airplane on TCDS No. 7A15 (including those models produced under the 
licensing agreement by Fairchild Republic Company) are included in the 
applicability. We are proposing this AD to detect and correct cracks in 
the rudder end rib, which could result in failure of the rudder end 
rib. This failure could result in loss of directional control.

DATES: We must receive comments on this proposed AD by May 24, 2006.

ADDRESSES: Use one of the following addresses to comment on this 
proposed AD:
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590-0001.
     Fax: (202) 493-2251.
     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.
    For service information identified in this proposed AD, contact 
Pilatus Aircraft Ltd., Customer Liaison Manager, CH-6371 Stans, 
Switzerland; telephone: +41 41 619 63 19; facsimile: +41 41 619 6224.

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

SUPPLEMENTARY INFORMATION:

[[Page 20920]]

Comments Invited

    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-
2006-24094; Directorate Identifier 2006-CE-20-AD'' 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://dms.dot.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

    Fatigue cracks found in the bottom nose rib on the rudders of 
certain Model PC-6 series airplanes prompted us to issue AD 68-17-03, 
Amendment 39-634. AD 68-17-03 currently requires the following on all 
Pilatus Aircraft Ltd. (Pilatus) Model PC-6 series airplanes:
     Repetitively inspecting the rudder end rib for cracks;
     Replacing the rudder end rib with a modified rudder end 
rib when you find cracks; and
     Terminating the repetitive inspections when the modified 
rudder end rib is installed.
    The Federal Office for Civil Aviation (FOCA), which is the 
airworthiness authority for Switzerland, notified the FAA of the need 
to revise AD 68-17-03 to address an unsafe condition that may exist or 
could develop on all Pilatus Model PC-6 series airplanes. The FOCA 
reports that clarification is needed to assure the applicability of AD 
68-17-03 to all Model PC-6 series airplanes listed on Type Certificate 
Data Sheet (TCDS) No. 7A15, including those produced in the United 
States through a licensing agreement between Pilatus and Fairchild 
Republic Company (also identified as Fairchild Industries, Fairchild 
Heli Porter, or Fairchild-Hiller Corporation).
    This condition, if not detected and corrected, could result in 
failure of the rudder end rib. This failure could result in loss of 
directional control.

Foreign Airworthiness Authority Information

    The FOCA recently issued Swiss AD Number HB 2005-289, effective 
date August 23, 2005, to ensure the continued airworthiness of all 
Model PC-6 series airplanes listed on TC No. 7A15, including those 
produced in the United States under a licensing agreement with Pilatus 
and Fairchild Republic Company (also identified as Fairchild 
Industries, Fairchild Heli Porter, or Fairchild-Hiller Corporation).
    The State of Design for Pilatus Model PC-6 series airplanes is 
Switzerland and the airplanes are type-certificated for operation in 
the United States under the provisions of section 21.29 of the Federal 
Aviation Regulations (14 CFR 21.29) and the applicable bilateral 
airworthiness agreement.
    Under this bilateral airworthiness agreement, the FOCA has kept us 
informed of the situation described above.

FAA's Determination and Requirements of This Proposed AD

    We are proposing this AD because we have examined the FOCA's 
findings, evaluated all information and determined the unsafe condition 
described previously is likely to exist or develop on other products of 
the same type design that are certificated for operation in the United 
States.
    This proposed AD would revise AD 68-17-03 with a new AD that would 
retain all actions currently required by AD 68-17-03 and would clarify 
the applicability of the affected airplanes by:
     Identifying those airplanes produced in the United States 
through a licensing agreement with the Fairchild Republic Company; and
     Listing all Pilatus Model PC-6 series airplanes on TCDS 
No. 7A15 in the applicability section.

Costs of Compliance

    We estimate that this proposed AD would affect 49 airplanes in the 
U.S. registry.
    We estimate the following costs to do the proposed inspection:

----------------------------------------------------------------------------------------------------------------
                                                        Total cost  per
           Labor cost                  Parts cost           airplane           Total cost on U.S. operators
----------------------------------------------------------------------------------------------------------------
1 work hour x $80 per hour = $80  Not applicable.....               $80   $80 x 49 = $3,920
----------------------------------------------------------------------------------------------------------------

    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 may need 
this replacement:

------------------------------------------------------------------------
                                                        Total cost  per
             Labor cost                  Parts cost         airplane
------------------------------------------------------------------------
9 work hours x $80 per hour = $720..            $821             $1,541
------------------------------------------------------------------------

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.

[[Page 20921]]

    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

Where Can I Go To View the Docket Information?

    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://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 Docket Office (telephone (800) 647-5227) 
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, 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 Airworthiness Directive 
(AD) 68-17-03, Amendment 39-634, and adding the following new AD:

Pilatus Aircraft LTD: Docket No. FAA-2006-24094; Directorate 
Identifier 2006-CE-20-AD.

Comments Due Date

    (a) We must receive comments on this proposed airworthiness 
directive (AD) action by May 24, 2006.

Affected ADs

    (b) This AD revises AD 68-17-03, Amendment 39-634.

Applicability

    (c) This AD affects the following airplane models, all 
manufacturer serial numbers (MSN), that are certificated in any 
category.

    Note: MSNs 2001 through 2092 were manufactured by Fairchild 
Republic Company (also identified as Fairchild Industries, Fairchild 
Heli Porter, and Fairchild-Hiller Corporation) in the United States 
under a license agreement and are covered by Type Certificate Data 
Sheet No. 7A15.

    (1) PC-6
    (2) PC-6-H1
    (3) PC-6-H2
    (4) PC-6/350
    (5) PC-6/350-H1
    (6) PC-6/350-H2
    (7) PC-6/A
    (8) PC-6/A-H1
    (9) PC-6/A-H2
    (10) PC-6/B-H2
    (11) PC-6/B1-H2
    (12) PC-6/B2-H2
    (13) PC-6/B2-H4
    (14) PC-6/C-H2
    (15) PC-6/C1-H2

Unsafe Condition

    (d) This AD results from fatigue cracks found in the bottom nose 
rib on the rudders of certain PC-6 airplanes. We are issuing this AD 
to detect and correct cracks in the rudder end rib, which could 
result in failure of the rudder. This failure could lead to loss of 
rudder control.

Compliance

    (e) To address this problem, you must do the following:

------------------------------------------------------------------------
            Actions                   Compliance           Procedures
------------------------------------------------------------------------
(1) With the aid of a mirror,   Within the next 50      Follow Pilatus
 inspect the rudder end rib,     hours time-in-service   Service
 part number (P/N) 6302.27 (or   (TIS) after August      Bulletin No.
 FAA-approved equivalent P/N)    19, 1968 (the           80, dated April
 for crack(s).                   effective date of AD    1968.
                                 68-17-03).
                                 Repetitively inspect
                                 thereafter at
                                 intervals not to
                                 exceed 50 hours TIS.
(2) If you detect crack(s)      Before further flight   Follow Pilatus
 during any inspection           after any inspection    Service
 required in paragraph (e)(1)    required in paragraph   Bulletin No.
 of this AD, replace the         (e)(1) of this AD in    80, dated April
 rudder end rib with a           which you find          1968.
 modified rudder end rib         cracks. Installing
 assembly, P/N 6302.26 Pos. 2,   the modified rudder
 channel reinforcement, P/N      end rib terminates
 113.40.06.002, and torque       the repetitive
 tube, P/N 113/40.06.003 (or     inspection
 FAA-approved equivalent P/Ns).  requirement in
                                 paragraph (e)(1) of
                                 this AD.
(3) 14 CFR 21.303 allows for    Not applicable........  Not applicable.
 replacement parts through
 parts manufacturer approval
 (PMA). The phrase ``or FAA-
 approved equivalent part
 number'' in this AD is
 intended to signify those
 parts that are PMA parts
 approved through identicality
 to the design of the part
 under the type certificate
 and replacement parts to
 correct the unsafe condition
 under PMA (other than
 identicality). If parts are
 installed that are identical
 to the unsafe parts, then the
 corrective actions of the AD
 affect these parts also. In
 addition, equivalent
 replacement parts to correct
 the unsafe condition under
 PMA (other than identicality)
 may also be installed
 provided they meet current
 airworthiness standards,
 which include those actions
 cited in this AD.
(4) Installing the modified     Not applicable........  Not applicable.
 rudder end rib assembly
 terminates the repetitive
 inspection requirement in
 paragraph (e)(1) of this AD.
------------------------------------------------------------------------


[[Page 20922]]

Alternative Methods of Compliance (AMOCs)

    (f) The Manager, Standards Office, 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 alternative methods of 
compliance (AMOCs) for this AD, if requested using the procedures 
found in 14 CFR 39.19.
    (g) AMOCs approved for AD 68-17-03 are approved for this AD.

Related Information

    (h) Swiss AD Number HB 2005-289, effective date August 23, 2005, 
also addresses the subject of this AD. To get copies of the 
documents referenced in this AD, contact Pilatus Aircraft Ltd., 
Customer Liaison Manager, CH-6371 Stans, Switzerland; telephone: +41 
41 619 63 19; facsimile: +41 41 619 6224. To view the AD docket, go 
to the Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-
401, Washington, DC, or on the Internet at http://dms.dot.gov. The 
docket number is Docket No. FAA-2006-24094; Directorate Identifier 
2006-CE-20-AD.

    Issued in Kansas City, Missouri, on April 17, 2006.
John R. Colomy,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E6-6055 Filed 4-21-06; 8:45 am]
BILLING CODE 4910-13-P