[Federal Register Volume 64, Number 120 (Wednesday, June 23, 1999)]
[Proposed Rules]
[Pages 33445-33447]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-15927]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-CE-119-AD]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to adopt a new airworthiness directive 
(AD) that would apply to certain Pilatus Aircraft Ltd. (Pilatus) Models 
PC-12 and PC-12/45 airplanes. The proposed AD would require inspecting 
all flap actuators in the internal gear system to assure that correct 
end-play and backlash measurements exist, and accomplishing any 
corrective adjustments as necessary. The proposed AD would also require 
incorporating a temporary revision into the Pilot's Operating Handbook 
(POH) in order to update operating procedures for the flap actuators; 
and would require incorporating temporary revisions to the maintenance 
manual in order to make the proposed inspection part of the future 
maintenance program. The proposed AD is the result of mandatory 
continuing airworthiness information (MCAI) issued by the airworthiness 
authority for Switzerland. The actions specified by the proposed AD are 
intended to prevent premature wear of the internal gear system caused 
by excessive backlash in the flight control flap actuators, which could 
eventually result in loss of actuator output with possible reduced or 
loss of airplane control.

DATES: Comments must be received on or before July 28, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Central Region, Office of the Regional Counsel, 
Attention: Rules Docket No. 98-CE-119-AD, Room 1558, 601 E. 12th 
Street, Kansas City, Missouri 64106. Comments may be inspected at this 
location between 8 a.m. and 4 p.m., Monday through Friday, holidays 
excepted.
    Service information that applies to the proposed 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 also may be examined at the Rules Docket at the 
address above.

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:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications should identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report that summarizes each FAA-public contact concerned 
with the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket No. 98-CE-119-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Central Region, Office of the Regional Counsel, Attention: 
Rules Docket No. 98-CE-119-AD, Room 1558, 601 E. 12th Street, Kansas 
City, Missouri 64106.

Discussion

    The Federal Office for Civil Aviation (FOCA), which is the 
airworthiness authority for Switzerland, recently notified the FAA that 
an unsafe condition may exist on certain Pilatus Models PC-12 and PC-
12/45 airplanes. The FOCA of Switzerland reports excessive backlash 
found in the flap actuators of the internal gear system. Excessive 
backlash will lead to premature wear of the gear.
    This condition, if not detected and corrected, could result in 
internal failure of the internal gear system with loss of actuator 
output and possible reduced or loss of airplane control.

Relevant Service Information

    Pilatus has issued Service Bulletin No. 27-005, November 18, 1998, 
which specifies procedures for:

--Inspecting all flap actuators in the internal gear system to assure 
that correct end-play and backlash measurements exist;
--Incorporating both Temporary Revision No. 27-04, and Temporary 
Revision No. 04-01, both dated November 18, 1998; into the Pilatus PC-
12 Maintenance Manual; and
--Incorporating PC-12 Pilot's Operating Handbook, Pilatus Report No. 
01973-001, Temporary Revision No. 4, Flap Actuators, dated November 18, 
1998.

    The FOCA of Switzerland classified this service bulletin as 
mandatory and issued Swiss AD HB 98-460, dated November 23, 1998, in 
order to assure the continued airworthiness of these airplanes in 
Switzerland.

The FAA's Determination

    This airplane model is manufactured in Switzerland and is 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. Pursuant to this 
bilateral airworthiness agreement, the FOCA of Switzerland has kept the 
FAA informed of the situation described above.

[[Page 33446]]

    The FAA has examined the findings of the FOCA of Switzerland; 
reviewed all available information, including the service information 
referenced above; and determined that AD action is necessary for 
products of this type design that are certificated for operation in the 
United States.

Explanation of the Provisions of the Proposed AD

    Since an unsafe condition has been identified that is likely to 
exist or develop in other Pilatus PC-12 and PC-12/45 airplanes of the 
same type design that incorporate a certain flight control flap 
actuator and that are registered in the United States, the FAA is 
proposing AD action. The proposed AD would require inspecting all flap 
actuators in the internal gear system to assure that correct end-play 
and backlash measurements exist, and accomplishing any corrective 
adjustments as necessary. The proposed AD would also require 
incorporating the temporary revision into the POH in order to update 
operating procedures for the flap actuators; and would require 
incorporating temporary revisions to the maintenance manual in order to 
make the proposed inspection part of the future maintenance program.
    The affected airplanes could incorporate one of the following 
flight control flap actuators:

--Pilatus part number (P/N) 978.71.20.302--Actuator, Linear (951D100-
5);
--Pilatus P/N 978.71.20.303--Actuator, Linear (951D100-7); and
--Pilatus P/N 978.71.20.304--Actuator, Linear (951D100-9).

    Accomplishment of the proposed inspection would be in accordance 
with Pilatus Service Bulletin No. 27-005, November 18, 1998. The 
proposed adjustments, if necessary, would be accomplished in accordance 
with the maintenance manual.

Cost Impact

    The FAA estimates that 69 airplanes in the U.S. registry would be 
affected by the proposed AD, that it would take approximately 6 
workhours per airplane to accomplish the proposed action, and that the 
average labor rate is approximately $60 an hour. The manufacturer will 
provide parts free-of-charge to the owners/operators of the affected 
aircraft. Based on these figures, the total cost impact of the proposed 
AD on U.S. operators is estimated to be $24,840, or $360 per airplane.
    Incorporating the proposed POH and maintenance manual revisions may 
be performed by the owner/operator holding at least a private pilot 
certificate as authorized by section 43.7 of the Federal Aviation 
Regulations (14 CFR 43.7), and must be entered into the aircraft 
records showing compliance with the proposed AD in accordance with 
section 43.9 of the Federal Aviation Regulations (14 CFR 43.9). The 
only cost impact the proposed POH and maintenance manual revision 
requirements impose is the time it would take each owner/operator of 
the affected airplanes to incorporate this information into the POH and 
maintenance manual.

Regulatory Impact

    The regulations proposed herein would 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 
proposal would 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) if promulgated, 
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 draft regulatory evaluation 
prepared for this action has been placed 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, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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:

    Pilatus Aircraft LtD.: Docket No. 98-CE-119-AD.

    Applicability: Models PC-12 and PC-12/45 airplanes, manufacturer 
serial numbers (MSN) 101 through MSN 236; certificated in any 
category, that have one of the following flight control flap 
actuators installed:

--Pilatus part number (P/N) 978.71.20.302--Actuator, Linear 
(951D100-5);
--Pilatus P/N 978.71.20.303--Actuator, Linear (951D100-7); and
--Pilatus P/N 978.71.20.304-- Actuator, Linear (951D100-9).

    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 (f) 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 premature wear of the internal gear system caused by 
excessive backlash in the flight control flap actuators, which could 
eventually result in loss of actuator output with possible reduced 
or loss of airplane control, accomplish the following:
    (a) Within the next 50 hours time-in-service (TIS) after the 
effective date of this AD, inspect all flap actuators in the 
internal gear system to assure that correct end-play and backlash 
measurements exist, in accordance with the ACCOMPLISHMENT 
INSTRUCTIONS section of Pilatus Service Bulletin No. 27-005, 
November 18, 1998. Prior to further flight, perform any corrective 
adjustments, as necessary, in accordance with the maintenance 
manual.
    (b) As of the effective date of this AD, no person may install, 
on any airplane, a flap actuator that has not been inspected and 
adjusted (as necessary) as required by paragraph (a) this AD.
    (c) Prior to further flight after the inspection and possible 
modification required by paragraph (a) of this AD, accomplish the 
following:
    (1) Insert Pilatus Report No. 01973-001, Temporary Revision No. 
4, Flap Actuators, dated November 18, 1998, into the Pilot's 
Operating Handbook (POH).
    (2) Insert Temporary Revision No. 27-04, and Temporary Revision 
No. 04-01, both dated November 18, 1998; into the Pilatus PC-12 
Maintenance Manual.
    (d) Accomplishment of the POH revision and maintenance manual 
insertions, as required by paragraph (c) of this AD, may be

[[Page 33447]]

performed by the owner/operator holding at least a private pilot 
certificate as authorized by section 43.7 of the Federal Aviation 
Regulations (14 CFR 43.7), and must be entered into the aircraft 
records showing compliance with this AD in accordance with section 
43.9 of the Federal Aviation Regulations (14 CFR 43.9).
    (e) Special flight permits may be issued in accordance with 
sections 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.
    (f) An alternative method of compliance or adjustment of the 
compliance times 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 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Small Airplane Directorate.

    (g) Questions or technical information related to Pilatus 
Service Bulletin No. 27-005, dated November 18, 1998, 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.

    Note 3: The subject of this AD is addressed in Swiss AD HB 98-
460, dated November 23, 1998.

    Issued in Kansas City, Missouri, on June 16, 1999.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 99-15927 Filed 6-22-99; 8:45 am]
BILLING CODE 4910-13-U