[Federal Register Volume 63, Number 95 (Monday, May 18, 1998)]
[Rules and Regulations]
[Pages 27195-27197]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-13060]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-CE-40-AD; Amendment 39-10528; AD 98-11-01]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment supersedes Airworthiness Directive (AD) 97-23-
04, which currently requires replacing the fuel tank vent valves with 
modified fuel tank vent valves on certain Pilatus Aircraft Ltd. 
(Pilatus) Models PC-12 and PC-12/45 airplanes. This AD retains the fuel 
tank vent valves replacement required by AD 97-23-04, and requires 
drilling a 4.8 millimeter (0.1875 inch) hole in each fuel filler cap. 
This AD also requires inserting a temporary revision in the Pilot's 
Operating Handbook (POH) that specifies checking to assure that the 
fuel filler cap hole is clear of ice and foreign objects. This AD is 
the result of mandatory continued airworthiness information (MCAI) 
issued by the airworthiness authority for Switzerland. The actions 
specified by this AD are intended to prevent the fuel tank inward vent 
valve from freezing, which, if followed by a cold soak at altitude, 
could result in wing airfoil distortion and structural damage with 
consequent degradation of the airplane's handling qualities.

DATES: Effective June 7, 1998.
    The incorporation by reference of Pilatus Service Bulletin No. 28-
003, Revision 1, dated September 30, 1997, as listed in the 
regulations, was previously approved by the Director of the Federal 
Register as of December 1, 1997 (62 FR 59993, November 6, 1997).
    The incorporation by reference of Pilatus Service Bulletin No. 28-
004, dated March 27, 1998, is approved by the Director of the Federal 
Register as of June 7, 1998.
    Comments for inclusion in the Rules Docket must be received on or 
before July 13, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Central Region, Office of the Regional Counsel, 
Attention: Rules Docket No. 98-CE-40-AD, Room 1558, 601 E. 12th Street, 
Kansas City, Missouri 64106.
    Service information that applies to this AD may be obtained from 
Pilatus Aircraft Ltd., CH-6370 Stans, Switzerland. This information may 
also be examined at the Federal Aviation Administration (FAA), Central 
Region, Office of the Regional Counsel, Attention: Rules Docket No. 98-
CE-40-AD, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106; 
or at the

[[Page 27196]]

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) 426-6934; facsimile:
    (816) 426-2169.

SUPPLEMENTARY INFORMATION:

Discussion

    AD 97-23-04, Amendment 39-10192 (62 FR 5993, ovember 6, 1997), 
currently requires replacing the fuel tank vent valves with modified 
fuel tank vent valves on certain Pilatus Models PC-12 and PC-12/45 
airplanes. AD 97-23-04 was the result of a report from the Federal 
Office for Civil Aviation (FOCA), which is the airworthiness authority 
for Switzerland, of an instance of abnormal automatic engagement of the 
fuel booster pumps during normal operation of a Pilatus Model PC-12 
airplane. The FOCA's investigation revealed that the fuel tank inward 
vent valves may fail in the closed position under certain conditions. 
Moisture ingestion, followed by cold soak, can lead to the fuel tank 
inward vent valve freezing.
    This condition, if not corrected, could result in wing airfoil 
distortion and structural damage with consequent degradation of the 
airplane's handling qualities.

Actions Since Issuance of Previous Rule

    The FOCA recently notified the FAA that an unsafe condition may 
still exist on certain Pilatus Models PC-12 and PC-12/45 airplanes, 
even after compliance with AD 97-23-04. The FOCA reports that the 
inward vent valve of the fuel tank froze closed on one of the affected 
airplanes that was in compliance with the fuel tank vent valves 
replacement requirement of AD 97-23-04. This resulted in permanent 
structural damage to the wing skins and ribs.

Relevant Service Information

    Pilatus has issued Service Bulletin No. 28-004, dated March 27, 
1998, which specifies procedures for drilling a 4.8 millimeter (0.1875 
inch) hole in each fuel filler cap. This service bulletin also 
references a temporary revision to the POH that specifies checking to 
assure that the fuel filler cap hole is clear of ice and foreign 
objects. This document is entitled ``PC-12 Pilot's Operating Handbook, 
Pilatus Report No. 01973-001, Temporary Revision, Fuel Filler Cap, 
dated March 27, 1998.''
    The FOCA of Switzerland classified this service bulletin as 
mandatory and issued Swiss AD HB 98-086, dated March 31, 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.
    The FAA has examined the findings of the FOCA of Switzerland; 
reviewed all available information, including the service bulletin 
referenced in this document; 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 This AD

    Since an unsafe condition has been identified that is likely to 
exist or develop in other Pilatus Models PC-12 and PC-12/45 airplanes 
of the same type design registered for operation in the United States, 
the FAA is issuing an AD to supersede AD 97-23-04. This AD retains the 
fuel tank vent valves replacement required by AD 97-23-04, and requires 
drilling a 4.8 millimeter (0.1875 inch) hole in each fuel filler cap. 
This AD also requires inserting the following temporary revision to the 
POH that specifies checking to assure that the fuel filler cap hole is 
clear of ice and foreign objects:

PC-12 Pilot's Operating Handbook, Pilatus Report No. 01973-001, 
Temporary Revision, Fuel Filler Cap, dated March 27, 1998.

    Accomplishment of the actions specified in this AD is required in 
accordance with the instructions in Pilatus Service Bulletin No. 28-
004, dated March 27, 1998.

Determination of the Effective Date of the AD

    Since a situation exists (possible wing airfoil distortion and 
structural damage with consequent degradation of the airplane's 
handling qualities) that requires the immediate adoption of this 
regulation, it is found that notice and opportunity for public prior 
comment hereon are impracticable, and that good cause exists for making 
this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting immediate flight safety and, thus, was not 
preceded by notice and opportunity to comment, comments are invited on 
this rule. Interested persons are invited to comment on this 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 will be considered, 
and this rule may be amended in light of the comments received. Factual 
information that supports the commenter's ideas and suggestions is 
extremely helpful in evaluating the effectiveness of the AD action and 
determining whether additional rulemaking action would be needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the 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 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket No. 98-CE-40-AD.'' The postcard will be date stamped and 
returned to the commenter.

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.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and is not a significant regulatory action under 
Executive Order 12866. It has been determined further that this action 
involves an emergency regulation under DOT Regulatory Policies and 
Procedures

[[Page 27197]]

(44 FR 11034, February 26, 1979). If it is determined that this 
emergency regulation otherwise would be significant under DOT 
Regulatory Policies and Procedures, a final regulatory evaluation will 
be prepared and placed in the Rules Docket (otherwise, an evaluation is 
not required). A copy of it, if filed, may be obtained from the Rules 
Docket.

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 removing Airworthiness Directive 
(AD) 97-23-04, Amendment No. 39-10192 (62 FR 59993, November 6, 1997), 
and by adding a new AD to read as follows:

98-11-01 Pilatus Aircraft, Ltd.: Amendment 39-10528; Docket No. 98-
CE-40-AD; Supersedes AD 97-23-04, Amendment No. 39-10192.

    Applicability: Models PC-12 and PC-12/45 airplanes; serial 
numbers 101 through 230, 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 (e) 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 fuel tank inward vent valve from freezing, which, 
if followed by a cold soak at altitude, could result in wing airfoil 
distortion and structural damage with consequent degradation of the 
airplane's handling qualities, accomplish the following:
    (a) Within the next 10 hours time-in-service (TIS) after 
December 1, 1997 (the effective date of AD 97-23-04), replace the 
fuel tank vent valves with modified fuel tank vent valves in 
accordance with the Accomplishment Instructions section of Pilatus 
Service Bulletin No. 28-003, Revision 1, dated September 30, 1997.
    (b) Within the next 10 hours TIS after the effective date of 
this AD, accomplish the following:
    (1) Drill a 4.8 millimeter (0.1875 inch) hole in each fuel 
filler cap in accordance with the Accomplishment Instructions 
section of Pilatus Service Bulletin No. 28-004, dated March 27, 
1998.
    (2) Insert a temporary revision (as referenced in Pilatus 
Service Bulletin 28-004, dated March 27, 1998) into the Pilot's 
Operating Handbook (POH) that specifies checking to assure that the 
fuel filler cap hole is clear of ice and foreign objects. This 
document is entitled ``PC-12 Pilot's Operating Handbook, Pilatus 
Report No. 01973-001, Temporary Revision, Fuel Filler Cap, dated 
March 27, 1998.''
    (c) Inserting the POH revision, as required by paragraph (b)(2) 
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).
    (d) 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.
    (e) 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, FAA, 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 97-23-04 (superseded by this action) are considered approved 
as alternative methods of compliance for this AD.

    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.

    (f) Questions or technical information related to Pilatus 
Service Bulletin No. 28-004, dated March 27, 1998, should be 
directed to Pilatus Aircraft Ltd., CH-6370 Stans, Switzerland. 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.
    (g) The replacement required by this AD shall be done in 
accordance with Pilatus Service Bulletin No. 28-003, Revision 1, 
dated September 30, 1997. The drilling required by this AD shall be 
done in accordance with Pilatus Service Bulletin No. 28-004, dated 
March 27, 1998.
    (1) The incorporation by reference of Pilatus Service Bulletin 
No. 28-003, Revision 1, dated September 30, 1997, was previously 
approved by the Director of the Federal Register as of December 1, 
1997 (62 FR 59993, November 6, 1997).
    (2) The incorporation by reference of Pilatus Service Bulletin 
No. 28-004, dated March 27, 1998, was approved by the Director of 
the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR 
part 51.
    (3) Copies of these service bulletins may be obtained from 
Pilatus Aircraft Ltd., CH-6370 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 3: The subject of this AD is addressed in Swiss AD HB 97-
432A, dated October 3, 1997, and Swiss AD HB 98-086, dated March 31, 
1998.

    (h) This amendment supersedes AD 97-23-04, Amendment No. 39-
10192.
    (i) This amendment becomes effective on June 7, 1998.

    Issued in Kansas City, Missouri, on May 8, 1998.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 98-13060 Filed 5-15-98; 8:45 am]
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