[Federal Register Volume 64, Number 156 (Friday, August 13, 1999)]
[Rules and Regulations]
[Pages 44112-44114]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-20568]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-CE-20-AD; Amendment 39-11250; AD 99-17-01]
RIN 2120-AA64


Airworthiness Directives; Pilatus Aircraft Ltd. Models PC-12 and 
PC-12/45 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
applies to certain Pilatus Aircraft Ltd. (Pilatus) Models PC-12 and PC-
12/45 airplanes. This AD requires replacing all flap drive shafts with 
flap drive shafts of improved design, installing additional gaskets on 
the power drive unit, and modifying the attachment and supporting 
hardware. This AD is the result of mandatory continuing airworthiness 
information (MCAI) issued by the airworthiness authority for 
Switzerland. The actions specified by this AD are intended to prevent 
the flap drive shafts from corroding to the point where the flexible 
shafts in the flap drive system rupture, which could result in the 
inability to utilize the flap system with reduced airplane control.

DATES: Effective October 1, 1999.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of October 1, 1999.

ADDRESSES: Service information that applies to this AD may be obtained 
from Pilatus Aircraft Ltd., Customer Liaison Manager, CH-6371 Stans, 
Switzerland; telephone: +41 41 619 63 19; facsimile: +41 41 610 33 51. 
This information may also be examined at the Federal Aviation 
Administration (FAA), Central Region, Office of the Regional Counsel, 
Attention: Rules Docket No. 99-CE-20-AD, Room 1558, 601 E. 12th Street, 
Kansas City, Missouri 64106; or at the Office of the Federal Register, 
800 North Capitol Street, NW, suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Mr. Roman T. Gabrys, Aerospace 
Engineer, FAA, Small Airplane Directorate, 1201 Walnut, suite 900, 
Kansas City, Missouri 64106; telephone: (816) 426-6932; facsimile: 
(816) 426-2169.

SUPPLEMENTARY INFORMATION:

[[Page 44113]]

Events Leading to the Issuance of This AD

    A proposal to amend part 39 of the Federal Aviation Regulations (14 
CFR part 39) to include an AD that would apply to certain Pilatus 
Models PC-12 and PC-12/45 airplanes was published in the Federal 
Register as a notice of proposed rulemaking (NPRM) on June 14, 1999 (64 
FR 31756). The NPRM proposed to require replacing all flap drive shafts 
with flap drive shafts of improved design, installing additional 
gaskets on the power drive unit, and modifying the attachment and 
supporting hardware. Accomplishment of the proposed action as specified 
in the NPRM would be required in accordance with Pilatus Service 
Bulletin No. 27-003, dated March 8, 1999.
    The NPRM was the result of mandatory continuing airworthiness 
information (MCAI) issued by the airworthiness authority for 
Switzerland.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were received on the 
proposed rule or the FAA's determination of the cost to the public.

The FAA's Determination

    After careful review of all available information related to the 
subject presented above, the FAA has determined that air safety and the 
public interest require the adoption of the rule as proposed except for 
minor editorial corrections. The FAA has determined that these minor 
corrections will not change the meaning of the AD and will not add any 
additional burden upon the public than was already proposed.

Compliance Time of This AD

    The unsafe condition specified by this AD is caused by corrosion. 
Corrosion can occur regardless of whether the aircraft is being 
operated. For example, corrosion could develop on one of the affected 
airplanes at a certain time; then, if allowed to go undetected, the 
corrosion could develop into a more serious problem even if the 
airplane is in storage. Therefore, to assure that the unsafe condition 
specified in this AD does not go undetected for a long period of time, 
the compliance is presented in calendar time instead of hours time-in-
service (TIS).

Cost Impact

    The FAA estimates that 69 airplanes in the U.S. registry will be 
affected by this AD, that it will take approximately 19 workhours per 
airplane to accomplish this action, and that the average labor rate is 
approximately $60 an hour. Parts will be provided by the manufacturer 
to the owners/operators of the affected aircraft free-of-charge. Based 
on these figures, the total cost impact of this AD on US operators is 
estimated to be $78,660, or $1,140 per airplane.

Regulatory Impact

    The regulations adopted herein will not have substantial direct 
effects 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. Therefore, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) Is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under 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. A copy of the final evaluation prepared for this 
action is contained in the Rules Docket. A copy of it may be obtained 
by contacting the Rules Docket at the location provided under the 
caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (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. Section 39.13 is amended by adding a new airworthiness directive 
(AD) to read as follows:

99-17-01  Pilatus Aircraft Ltd.: Amendment 39-11250; Docket No. 99-
CE-20-AD.

    Applicability: Models PC-12 and PC-12/45 airplanes, manufacturer 
serial number (MSN) 101 through 239, certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (d) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated in the body of this AD, unless 
already accomplished.
    To prevent the flap drive shafts from corroding to the point 
where the flexible shafts in the flap drive system rupture, which 
could result in the inability to utilize the flap system with 
reduced airplane control, accomplish the following:
    (a) Within the next 4 calendar months after the effective date 
of this AD, accomplish the following in accordance with the 
Accomplishment Instructions section of Pilatus Service Bulletin No. 
27-003, dated March 8, 1999:
    (1) Replace all flap drive shafts with flap drive shafts of 
improved design (part numbers as specified in paragraphs (b)(1) and 
(b)(2) of this AD);
    (2) Install additional gaskets on the power drive unit; and
    (3) Modify the attachment and supporting hardware.
    (b) As of the effective date of this AD, no person may install, 
on any affected airplane, a flap drive shaft assembly that is not of 
the following part numbers (or FAA-approved equivalent part 
numbers):
    (1) Part number 945.02.02.201: Flap Drive Shaft 953D100-5 
(Inboard); and
    (2) Part-number 945.02.02.202: Flap Drive Shaft 953D100-7 
(Outboard).

    Note 2: The FAA recommends that the owner/operator of the 
affected airplanes insert Pilatus Temporary Revision No. 27-07, 
dated January 8, 1999, into the PC12 Maintenance Manual at the same 
time this AD is accomplished to assure that the maintenance 
procedures for the improved design parts are current.

    (c) Special flight permits may be issued in accordance with 
Secs. 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 
21.197 and 21.199) to operate the airplane to a location where the 
requirements of this AD can be accomplished.
    (d) An alternative method of compliance or adjustment of the 
compliance time that provides an equivalent level of safety may be 
approved by the Manager, Small Airplane Directorate, 1201 Walnut, 
suite 900, Kansas City, Missouri 64106. The request shall be 
forwarded through an appropriate FAA Maintenance Inspector, who may 
add comments and then send it to the Manager, Small Airplane 
Directorate.

    Note 3: Information concerning the existence of approved 
alternative methods of

[[Page 44114]]

compliance with this AD, if any, may be obtained from the Small 
Airplane Directorate.

    (e) Questions or technical information related to Pilatus 
Service Bulletin No: 27-003, dated March 8, 1999, should be directed 
to Pilatus Aircraft Ltd., Customer Liaison Manager, CH-6371 Stans, 
Switzerland; telephone: +41 41 619 63 19; facsimile: +41 41 610 33 
51. This service information may be examined at the FAA, Central 
Region, Office of the Regional Counsel, Room 1558, 601 E. 12th 
Street, Kansas City, Missouri 64106.
    (f) The replacements, installations, and modification required 
by this AD shall be done in accordance with Pilatus Service Bulletin 
No: 27-003, dated March 8, 1999. This incorporation by reference was 
approved by the Director of the Federal Register in accordance with 
5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from 
Pilatus Aircraft Ltd., Customer Liaison Manager, CH-6371 Stans, 
Switzerland. Copies may be inspected at the FAA, Central Region, 
Office of the Regional Counsel, Room 1558, 601 E. 12th Street, 
Kansas City, Missouri, or at the Office of the Federal Register, 800 
North Capitol Street, NW, suite 700, Washington, DC.

    Note 4: The subject of this AD is addressed in Swiss AD HB 99-
241, dated May 8, 1999.

    (g) This amendment becomes effective on October 1, 1999.

    Issued in Kansas City, Missouri, on August 3, 1999.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 99-20568 Filed 8-12-99; 8:45 am]
BILLING CODE 4910-13-P