[Federal Register Volume 64, Number 187 (Tuesday, September 28, 1999)]
[Proposed Rules]
[Pages 52260-52263]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-25222]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-CE-61-AD]
RIN 2120-AA64


Airworthiness Directives; Pilatus Aircraft Ltd. Model PC-7 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to supersede Airworthiness Directive 
(AD) 98-08-07, which currently requires replacing the rudder and 
elevator pivot arms with parts of improved design on

[[Page 52261]]

certain Pilatus Aircraft Ltd. (Pilatus) Model PC-7 airplanes. The 
proposed AD would require replacing the rudder and elevator pivot arms 
with parts that have been improved since issuance of AD 98-08-07. 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 failure of the elevator and rudder caused by fatigue cracking 
of the pivot arms, which could result in reduced airplane 
controllability and possible loss of control of the airplane.

DATES: Comments must be received on or before October 27, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Central Region, Office of the Regional Counsel, 
Attention: Rules Docket No. 99-CE-61-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 65 09; facsimile: +41 41 610 33 51. 
This information also may be examined at the Rules Docket at the 
address above.

FOR FURTHER INFORMATION CONTACT: Roman T. Gabrys, Aerospace Engineer, 
FAA, Small Airplane Directorate, FAA, 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. 99-CE-61-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. 99-CE-61-AD, Room 1558, 601 E. 12th Street, Kansas 
City, Missouri 64106.

Discussion

    AD 98-08-07, Amendment 39-10456 (63 FR 17323, April 9, 1998), 
currently requires replacing the rudder and elevator pivot arms with 
the following parts of improved design, on certain Pilatus Model PC-7 
airplanes:

------------------------------------------------------------------------
                      Designation                         New part No.
------------------------------------------------------------------------
Pivot Arm--Left-hand Elevator.........................     113.50.07.108
Pivot Arm--Right-hand Elevator........................     113.50.07.109
Pivot Arm--Upper Rudder...............................     113.40.07.084
Pivot Arm--Lower Rudder...............................     113.40.07.083
------------------------------------------------------------------------

    Accomplishment of AD 98-08-07 was required in accordance with 
Pilatus Service Bulletin No. PC7-55-001, Revision No. 1, dated June 20, 
1995.
    AD 98-08-07 was the result of reports of cracks in the elevator and 
rudder trim tab pivot arms on the above-referenced airplanes.
    The actions specified in AD 98-08-07 were intended to prevent 
failure of the elevator and rudder caused by fatigue cracking of the 
pivot arms, which could result in reduced airplane controllability and 
possible loss of control of the airplane.

Actions Since Issuance of Previous Rule

    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 PC-7 airplanes. The 
FOCA of Switzerland advises that cracks have been found in the improved 
design rudder and elevator pivot arms that are specified in Pilatus 
Service Bulletin No. PC7-55-001, Revision No. 1, dated June 20, 1995, 
and mandated to be installed by AD 98-08-07.
    Analyis reveals that the cause of the cracks is due to a 
manufacturing defect where the manufacturing process deviated from the 
design specifications.

Relevant Service Information

    Pilatus has issued Service Bulletin No. 55-003, dated July 7, 1999, 
which specifies procedures for replacing the rudder and elevator pivot 
arms with parts of improved design, as follows:

------------------------------------------------------------------------
                               Previous part  No.
         Designation            installed  per AD       New part No.
                                    98-08-07
------------------------------------------------------------------------
Pivot Arm, Inner Elevator....       113.50.07.108  113.50.07.108
                                                   (green paint).
Pivot Arm, Outer Elevator....       113.50.07.109  113.50.07.109
                                                   (green paint).
Pivot Arm, Upper Rudder......       113.40.07.084  113.40.07.084
                                                   (green paint).
Pivot Arm, Lower Rudder......       113.40.07.083  113.40.07.083
                                                   (green paint).
------------------------------------------------------------------------

    The FOCA classified this service bulletin as mandatory and issued 
Swiss Airworthiness Directive HB 99-412, Effective Date: August 31, 
1999, 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

[[Page 52262]]

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.
    The FAA has examined the findings of the FOCA; reviewed all 
available information, including the referenced service information; 
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-7 airplanes of the same type 
design registered for operation in the United States, the FAA is 
proposing AD action to supersede AD 98-08-07. The proposed AD would 
require replacing the rudder and elevator pivot arms with parts that 
have been improved since issuance of AD 98-08-07.

Cost Impact

    The FAA estimates that 8 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. Parts cost 
approximately $300 per airplane. Based on these figures, the total cost 
impact of the proposed AD on U.S. operators is estimated to be $5,280, 
or $660 per airplane.

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 removing Airworthiness Directive 
(AD) 98-08-07, Amendment 39-10456, and by adding a new AD to read as 
follows:

Pilatus Aircraft Ltd.: Docket No. 99-CE-61-AD; Supersedes AD 98-08-
07, Amendment 39-10456.

    Applicability: Model PC-7 airplanes, manufacturer serial number 
(MSN) 001 through MSN 614, 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 fatigue failure of the elevator and rudder trim tab 
pivot arms because of cracks, which could result in the loss of 
airplane control, accomplish the following:
    (a) Within the next 100 hours time-in-service (TIS) after the 
effective date of this AD, replace the rudder and elevator pivot 
arms with parts of improved design (or FAA-approved equivalent part 
numbers), as specified in and in accordance with Pilatus Service 
Bulletin No. 55-003, dated July 7, 1999. The part numbers of the 
improved design pivot arms are reflected in the following chart:

------------------------------------------------------------------------
                                Previous part No.
         Designation            installed per AD        New part No.
                                    98-08-07
------------------------------------------------------------------------
Pivot Arm, Inner Elevator....       113.50.07.108  113.50.07.108
                                                   (green paint).
Pivot Arm, Outer Elevator....       113.50.07.109  113.50.07.109
                                                   (green paint).
Pivot Arm, Upper Rudder......       113.40.07.084  113.40.07.084
                                                   (green paint).
Pivot Arm, Lower Rudder......       113.40.07.083  113.40.07.083
                                                   (green paint).
------------------------------------------------------------------------

    (b) As of the effective date of this AD, no person may install, 
on any of the affected airplanes, an elevator or rudder pivot arm 
that is not of the improved design specified in paragraph (a) of 
this AD.
    (c) 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.
    (d) 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.
    (1) 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.
    (2) Alternative methods of compliance approved in accordance 
with AD 98-08-07 are not considered approved as alternative methods 
of compliance for this AD.


[[Page 52263]]


    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.

    (e) Questions or technical information related to Pilatus 
Service Bulletin No. 55-003, dated July 7, 1999, should be directed 
to Pilatus Aircraft Ltd., Customer Liaison Manager, CH-6371 Stans, 
Switzerland; telephone: +41 41 619 65 09; 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 
Airworthiness Directive HB 99-412, Effective Date: August 31, 1999.

    (f) This amendment supersedes AD 98-08-07, Amendment 39-10456.

    Issued in Kansas City, Missouri, on September 20, 1999.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 99-25222 Filed 9-27-99; 8:45 am]
BILLING CODE 4910-13-U