[Federal Register Volume 63, Number 147 (Friday, July 31, 1998)]
[Rules and Regulations]
[Pages 40807-40809]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-20439]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-CE-40-AD; Amendment 39-10681; AD 98-11-01 R2]
RIN 2120-AA64
Airworthiness Directives; Pilatus Aircraft Ltd. Models PC-12 and
PC-12/45 Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; correction.
-----------------------------------------------------------------------
SUMMARY: This amendment clarifies information contained in
Airworthiness Directive (AD) 98-11-01 R1, 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 R1 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. The intent of AD 98-11-01
R1 was to provide the option of incorporating new modified fuel tank
vent valves instead of the replacement, drilling, and POH insertion
requirements. The new modified vent valves cannot be incorporated
without removing the fuel tank vent valves installed as originally
required by AD 97-23-04 and carried over in the current AD. This
provision of removing those vent valves is currently not provided for.
This document clarifies and corrects this procedure. 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, was previously approved by the Director of the
Federal Register as of September 22, 1998 (63 FR 34565, June 25, 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, Amendment 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
[[Page 40808]]
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.
Pilatus then 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 FAA followed by issuing AD 98-11-01 R1, mendment 39-10608 (63
FR 34565, June 25, 1998), to incorporate Pilatus Service Bulletin No.
28-005, dated May 4, 1998, as an alternative method of compliance to AD
98-11-01 R1.
Need for the Correction
The way AD 98-11-01 R1 is currently written makes it impossible for
the new modified fuel vent valves to be incorporated because it does
not provide the option of removing the previous replacement fuel tank
vent valves as originally required by AD 97-23-04 and carried over in
the current AD. In particular, paragraph (d) reads:
(d) As an alternative method of compliance to the actions
required in paragraph (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.
Paragraph (b)(1) requires the 4.8 millimeter hole to be drilled in each
filler cap and paragraph (b)(2) requires the insertion of the temporary
POH revision. Paragraph (a) requires replacement of the fuel tank vent
valves.
The new modified vent valves cannot be incorporated without
removing the vent valves required by paragraph (a) of the current AD.
AD 98-11-01 R1 currently does not provide for this.
Consequently, the FAA sees a need to clarify AD 98-11-01 R1 to
assure that the modification can be fully carried out as an alternative
method of compliance for all the actions of the AD.
Correction of Publication
This document clarifies the intent of the fuel tank vent valve
modification specified in Pilatus Service Bulletin No. 28-005, dated
May 4, 1998, as an alternative method of compliance to all of the
actions of AD 98-11-01 R1. This document also adds the amendment to
section 39.13 of the Federal Aviation Regulations (14 CFR 39.13).
Since this action only clarifies the intent of the fuel tank vent
valve modication, it has no adverse economic impact and imposes no
additional burden on any person than would have been necessary to
comply with paragraph (d) of AD 98-11-01 R1. Therefore, the FAA has
determined that prior notice and opportunity for public comment are
unnecessary.
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 R1, Amendment 39-10608 (63 FR 34565, June 25, 1998), and
by adding a new AD to read as follows:
98-11-01 R1 Pilatus Aircraft, Ltd.: Amendment 39-10681; Docket No.
98-CE-40-AD; Revises AD 98-11-01 R1, Amendment 39-10608; which
revised AD 98-11-01, Amendment 39-10528; which superseded AD 97-23-
04, Amendment 39-34565.
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 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).
[[Page 40809]]
(d) As an alternative method of compliance to the actions
required by this AD, including the actions in paragraphs (a),
(b)(1), and (b)(2), 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 R1 (revised by this action), AD 98-11-01 (revised
by AD 98-11-01 R1), and 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, 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 previously 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, was previously approved by the
Director of the Federal Register as of September 22, 1998 (63 FR
34565, June 25, 1998).
(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 R1, amendment 39-10608;
which revised 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 July 23, 1998.
Michael Gallagher,
Acting Manager, Small Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-20439 Filed 7-30-98; 8:45 am]
BILLING CODE 4910-13-U