[Federal Register Volume 63, Number 122 (Thursday, June 25, 1998)]
[Rules and Regulations]
[Pages 34565-34567]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-16163]



[[Page 34565]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-CE-40-AD; Amendment 39-10608; AD 98-11-01 R1]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Direct final rule; request for comments.

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SUMMARY: This amendment revises Airworthiness Directive (AD) 98-11-01, 
which currently requires replacing the fuel tank vent valves and 
drilling a 4.8 millimeter (0.1875 inch) hole in each fuel filler cap on 
certain Pilatus Aircraft Ltd. (Pilatus) Models PC-12 and PC-12/45 
airplanes. AD 98-11-01 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 maintains the requirements of AD 98-11-01, and adds the option of 
modifying the fuel tank vent valves instead of the drilling and POH 
requirements carried over from AD 98-11-01. This AD is the result of 
mandatory continuing airworthiness information (MCAI) issued by the 
airworthiness authority for Switzerland. The actions specified in this 
AD are intended to continue to prevent moisture from entering the fuel 
tank inward vent valve and then freezing after a cold soak at altitude, 
which could result in wing airfoil distortion and structural damage 
with consequent degradation of the airplane's handling qualities.

DATES: Effective September 22, 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, as listed in the regulations, was previously 
approved by the Director of the Federal Register as of June 7, 1998 (63 
FR 27195, May 18, 1998).
    The incorporation by reference of Pilatus Service Bulletin No. 28-
005, dated May 4, 1998, is approved by the Director of the Federal 
Register as of September 22, 1998.
    Comments for inclusion in the Rules Docket must be received on or 
before July 24, 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 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

    On October 29, 1997, the FAA issued AD 97-23-04, mendment 39-10192 
(62 FR 5993, November 6, 1997), which applies to 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.
    AD 97-23-04 required replacing the fuel tank vent valves with 
modified fuel tank vent valves before the FAA superseded it with AD 98-
11-01, Amendment 39-10528 (63 FR 27195, May 18, 1998). AD 98-11-01 
currently requires 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 replacement is required in accordance with 
Pilatus Service Bulletin No. 28-003, Revision 1, dated September 30, 
1997. Accomplishment of the drilling and POH insertion is required in 
accordance with Pilatus Service Bulletin No. 28-004, dated March 27, 
1998.
    AD 98-11-01 was the result of a report of an incident where 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.
    This condition, if not corrected, could result in wing airfoil 
distortion and structural damage with consequent degradation of the 
airplane's handling qualities.

Relevant Service Information

    Pilatus has issued Service Bulletin No. 28-005, dated May 4, 1998, 
which specifies procedures for modifying the fuel tank vent valves. 
This modification, when incorporated, would eliminate the need for the 
drilling and POH requirements of AD 98-11-01.
    The FOCA of Switzerland classified this service bulletin as 
mandatory and issued Swiss AD HB 98-126, dated May 15, 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 
Sec. 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 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 This AD

    Since an unsafe condition has been identified that is likely to 
exist or develop in other Models PC-12 and PC-12/45 airplanes of the 
same type design registered in the United States, the FAA

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is issuing an AD to revise AD 98-11-01. This AD:

--Maintains the requirements in AD 98-11-01 of replacing the fuel tank 
vent valves, drilling a 4.8 millimeter (0.1875 inch) hole in each fuel 
filler cap, and inserting a temporary revision in the POH that 
specifies checking to assure that the fuel filler cap hole is clear of 
ice and foreign objects; and
--Adds the option of modifying the fuel tank vent valves instead of the 
drilling and POH requirements carried over from AD 98-11-01.

    Accomplishment of the actions specified in this AD would be 
required in accordance with the following:

--Replacement: Pilatus Service Bulletin No. 28-003, Revision 1, dated 
September 30, 1997;
--Drilling: Pilatus Service Bulletin No. 28-004, dated March 27, 1998; 
and
--Modification: Pilatus Service Bulletin No. 28-005, dated May 4, 1998.

Cost Impact

    The FAA estimates that 100 airplanes in the U.S. registry will be 
affected by this AD. The only difference between this AD and AD 98-11-
01 is the provision of accomplishing the modification instead of the 
drilling and POH insertion requirements carried over from AD 98-11-01. 
This replacement takes approximately 8 workhours per airplane to 
accomplish at an average labor rate of approximately $60 per work hour. 
Parts will be provided at no cost to the owner/operator of the affected 
airplanes. Based on these figures, the cost impact of this AD on U.S. 
operators that choose to incorporate the modification option instead of 
the drilling and POH requirements carried over from AD 98-11-01 is 
estimated to be $48,000, or $480 per airplane.

The Direct Final Rule Procedure

    The FAA anticipates that this regulation will not result in adverse 
or negative comment and therefore is issuing it as a direct final rule. 
The requirements of this direct final rule address an unsafe condition 
identified by a foreign civil airworthiness authority and do not impose 
a significant burden on affected operators. In accordance with 
Sec. 11.17 of the Federal Aviation Regulations (14 CFR 11.17) unless a 
written adverse or negative comment, or a written notice of intent to 
submit an adverse or negative comment, is received within the comment 
period, the regulation will become effective on the date specified 
above. After the close of the comment period, the FAA will publish a 
document in the Federal Register indicating that no adverse or negative 
comments were received and confirming the date on which the final rule 
will become effective. If the FAA does receive, within the comment 
period, a written adverse or negative comment, or written notice of 
intent to submit such a comment, a document withdrawing the direct 
final rule will be published in the Federal Register, and a notice of 
proposed rulemaking may be published with a new comment period.

Comments Invited

    Although this action is in the form of a final rule and was not 
preceded by notice and an opportunity for public 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 shall identify the Rules Docket number and be 
submitted in triplicate to the address specified under the caption 
ADDRESSES. 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 noncontroversial and 
unlikely to result in adverse or negative comments. For reasons 
discussed in the preamble, I certify that this regulation (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 final 
evaluation has been prepared for this action and is contained in the 
Rules Docket. A copy of it may be obtained from 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 removing Airworthiness Directive 
(AD) 98-11-01, Amendment 39-10528 (63 FR 27195, May 18, 1998), and by 
adding a new AD to read as follows:

98-11-01  R1 Pilatus Aircraft, LTD.: Amendment 39-10608; Docket No. 
98-CE-40-AD; Revises AD 98-11-01, Amendment 39-10528.

    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 (f) of 
this AD. The request should include an assessment of the

[[Page 34567]]

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 moisture from entering the fuel tank inward vent 
valve and then freezing after a cold soak at altitude, which 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 June 7, 1998 (the 
effective date of AD 98-11-01), 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) As an alternative method of compliance to the actions 
required in paragraphs (b)(1) and (b)(2) of this AD, modify the fuel 
tank vent valve system in accordance with the Accomplishment 
Instructions section of Pilatus Service Bulletin No. 28-005, dated 
May 4, 1998.
    (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, 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 98-11-01 (superseded by this action) and with AD 97-23-04 
(superseded by AD 98-11-01) 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.

    (g) Questions or technical information to the service 
information referenced in this document 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.
    (h) 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. The modification required by this AD shall be done 
in accordance with Pilatus Service Bulletin No. 28-005, dated May 4, 
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 as of June 7, 1998 (63 FR 27195, May 18, 1998).
    (3) The incorporation by reference of Pilatus Service Bulletin 
No. 28-005, dated May 4, 1998, is approved by the Director of the 
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 
51.
    (4) 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; Swiss AD HB 98-086, dated March 31, 
1998; and Swiss AD HB 98-126, dated May 15, 1998.

    (i) This amendment revises AD 98-11-01, Amendment 39-10528; 
which superseded AD 97-23-04, Amendment No. 39-10192.
    (j) This amendment becomes effective on September 22, 1998.

    Issued in Kansas City, Missouri, on June 11, 1998.
Ronald K. Rathgeber,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-16163 Filed 6-24-98; 8:45 am]
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