[Federal Register Volume 63, Number 62 (Wednesday, April 1, 1998)]
[Proposed Rules]
[Pages 15795-15797]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-8462]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-CE-08-AD]
RIN 2120-AA64


Airworthiness Directives; Pilatus Aircraft Ltd. Model PC-12 
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) Model 
PC-12 airplanes. The proposed action would require replacing and re-
routing the power return cables on the starter generator and generator 
2, inserting a temporary revision to the pilot operating handbook 
(POH), and installing a placard near the standby magnetic compass. 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 directional deviation on the standby magnetic compass caused by 
an overload of electrical current in the airplane structure, which, if 
not corrected, could result in flight-path deviation during critical 
phases of flight in icing conditions and instrument meteorologic 
conditions (IMC).

DATES: Comments must be received on or before May 4, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Central Region, Office of the Regional Counsel, 
Attention: Rules Docket No. 97-CE-08-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., Marketing Support Department, CH-6370 
Stans, Switzerland; telephone: +41 41-6196 233; facsimile: +41 41-6103 
351. This information also may be examined at the Rules Docket at the 
address above.

FOR FURTHER INFORMATION CONTACT: Roman T. Gabrys, Aerospace Engineer, 
Small Airplane Directorate, Airplane Certification Service, 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. 97-CE-08-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. 97-CE-08-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 Model PC-12 airplanes. 
FOCA reports that directional deviations are occurring on the standby 
magnetic compass when some systems are in operation during flight. A 
magnetic field created by additional electric loads caused unreliable 
readings on the compass while the airplane was flying in IMC and the 
pilot was relying on the Attitude and Heading Reference Systems (AHRS).
    These conditions, if not corrected, could result in a deviation of 
the

[[Page 15796]]

airplane flight path during critical phases of flight.

Relevant Service Information

    Pilatus has issued PC XII Service Bulletin No. 24-002, Revision No. 
1, dated September 20, 1996, which specifies procedures for re-routing 
and replacing the power return cables on the starter generator and 
generator 2, inserting a temporary revision in the pilot operating 
handbook (POH), and installing a placard near the standby magnetic 
compass.
    FOCA classified this service bulletin as mandatory and issued Swiss 
AD number HB 96-140, dated March 18, 1996, and Swiss AD number HB 97-
001, dated January 1, 1997, 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, FOCA 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 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 Model PC-12 airplanes of the same 
type design registered in the United States, the FAA is proposing AD 
action. The proposed AD would require replacing and re-routing the 
power return cables on the starter generator and generator 2; inserting 
a temporary revision to the POH; and installing a placard near the 
standby magnetic compass, using at least \1/8\-inch letters, with the 
following words:
STANDBY COMPASS FOR CORRECT READING CHECK: WINDSHIELD DE-ICE LH & RH 
HEAVY & COOLING SYSTEM OFF''
    Accomplishment of the proposed actions would be in accordance with 
Pilatus PC XII Service Bulletin No. 24-002, Revision No. 1, dated 
September 20, 1996.

Cost Impact

    The FAA estimates that 40 airplanes in the U.S. registry would be 
affected by the proposed AD, that it would take approximately 12 
workhours per airplane to accomplish the proposed action, and that the 
average labor rate is approximately $60 an hour. Parts cost will be 
provided free from the manufacturer upon request. Based on these 
figures, the total cost impact of the proposed AD on U.S. operators is 
estimated to be $28,800 or $720 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 adding a new airworthiness directive 
(AD) to read as follows:

Pilatus Aircraft Ltd.: Docket No. 97-CE-08-AD.

    Applicability: Model PC-12 airplanes (serial numbers 101 through 
147), 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 (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 within the next 100 hours time-in-service 
(TIS) after the effective date of this AD, unless already 
accomplished.
    To prevent directional deviation on the standby magnetic compass 
caused by an overload of electrical current in the airplane 
structure, which, if not corrected, could result in flight-path 
deviation during critical phases of flight in icing conditions and 
Instrument Meteorologic Conditions (IMC), accomplish the following:
    (a) Re-route and replace the starter generator cable and the 
generator 2 power return cables with new cables of improved design 
in accordance with the Accomplishment Instructions section in 
Pilatus PC XII Service Bulletin (SB) No. 24-002, Revision No. 1, 
dated September 20, 1996.
    (b) Remove the temporary revision titled ``Electrical Cables,'' 
dated March 7, 1996 from the Pilot Operating Handbook (POH) and 
insert a temporary revision titled ``Electrical Cables'' Rev. 1, 
dated July 12, 1996, in accordance with the Accomplishment 
Instructions section in Pilatus PC XII SB No. 24-002, Revision No. 
1, dated September 20, 1996.
    (c) Install a placard with the following words (using at least 
\1/8\-inch letters) near the standby magnetic compass in accordance 
with the Accomplishment Instructions section in Pilatus PC XII SB 
No. 24-002, Revision No. 1, dated September 20, 1996:

``STANDBY COMPASS FOR CORRECT READING CHECK: WINDSHIELD DE-ICE LH & RH 
HEAVY & COOLING SYSTEM OFF''

    (d) Incorporating the AFM revisions and installing a placard, as 
required by paragraphs (b) and (c) of this AD, 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 this AD in accordance with section 43.9 of the 
Federal Aviation Regulations (14 CFR 43.9).

[[Page 15797]]

    (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 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 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 PC XII 
Service Bulletin No. 24-002, Revision No. 1, dated September 20, 
1996, should be directed to Pilatus Aircraft Ltd., Customer Liaison 
Manager, CH-6370 Stans, Switzerland; telephone: +41 41 6196 233; 
facsimile: +41 41 6103 351. 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 Nos. HB-
96-140, dated March 18, 1996 and HB 97-001 dated, January 1, 1997.

    Issued in Kansas City, Missouri, on March 24, 1998.
Carolanne Cabrini,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-8462 Filed 3-31-98; 8:45 am]
BILLING CODE 4910-13-U