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

[Federal Register Volume 66, Number 109 (Wednesday, June 6, 2001)]
[Rules and Regulations]
[Pages 30300-30302]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-13580]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-CE-82-AD; Amendment 39-12243; AD 2001-11-02]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes Airworthiness Directive (AD) 99-17-
08, which currently requires modifying the generator 2 excitation by 
removing certain diodes and installing a new 5-amp circuit breaker and 
suppression filter on certain Pilatus Aircraft Ltd. (Pilatus) Models 
PC-12 and PC-12/45 airplanes. This AD is the result of the Federal 
Aviation Administration's determination that the A250 voltage spike 
suppression filter in the modification kit can cause the circuit 
breaker 235 to trip because of overload. In extreme circumstances, this 
can lead to overheating of wiring. This AD requires you to modify the 
generator 2 excitation by removing certain diodes and installing a new 
5-amp circuit breaker and suppression filter of improved design in 
accordance with revised procedures. This AD is the result of mandatory 
continuing airworthiness information (MCAI) issued by the airworthiness 
authority for Switzerland. The actions specified by this AD are 
intended to prevent damage to electrical components if generator 2 is 
not switched off before engine shutdown and it overheats. This could 
result in loss of electrical power to certain critical airplane 
components.

DATES: This AD becomes effective on July 23, 2001.
    The Director of the Federal Register approved the incorporation by 
reference of Pilatus Service Bulletin No. 24-014, dated October 27, 
1999, as of July 23, 2001.
    The Director of the Federal Register previously approved the 
incorporation by reference of Pilatus Service Bulletin No. 24-012, 
dated February 19, 1999, as of October 4, 1999 (64 FR 45149, August 19, 
1999).

ADDRESSES: You may get the service information referenced in this AD 
from Pilatus Aircraft Ltd., Customer Liaison Manager, CH-6371 Stans, 
Switzerland; telephone: +41 41 619 65 09; facsimile: +41 41 610 33 51. 
You may examine this information at the Federal Aviation Administration 
(FAA), Central Region, Office of the Regional Counsel, Attention: Rules 
Docket No. 99-CE-82-AD, 901 Locust, Room 506, 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: Doug Rudolph, Aerospace Engineer, FAA, 
Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 
64106; telephone: (816) 329-4059; facsimile: (816) 329-4090.

SUPPLEMENTARY INFORMATION:   

Discussion

Has FAA Taken Any Action to This Point?

    The FAA issued AD 99-17-08, Amendment 39-11256 (64 FR 45149, August 
19, 1999), against Pilatus models PC-12 and PC-12/45 airplanes, to 
prevent damage to electrical components if generator 2 is not switched 
off before engine shutdown and it overheats. This could result in loss 
of electrical power to certain critical airplane components.
    AD 99-17-08 requires that you do the following on the affected 
airplanes:

--modify the generator 2 excitation by removing certain diodes; and
--install a new 5-amp circuit breaker and suppression filter.

    AD 99-17-08 was the result of mandatory continuing airworthiness 
information (MCAI) issued by the airworthiness authority for 
Switzerland.

What Has Happened Since AD 99-17-08 To Begin This Action?

    The Federal Office for Civil Aviation (FOCA), which is the 
airworthiness authority for Switzerland, notified the FAA of the need 
to change AD 99-17-08. The FOCA reports that after installation of the 
modification kit in accordance with Pilatus Service Bulletin SB 24-012 
and turning on electrical power on one of the affected airplanes, the 
circuit breaker CB 235 tripped.
    Investigation revealed that the suppression filter (A250) (part 
number 524.52.12.358) was shorted. The suppression diode installed in 
the filter was shorted and was the wrong type. The manufacturer's A250 
voltage spike suppression filter is inadequate and has been replaced 
with an A250 voltage spike suppression filter of improved design.

Has FAA Taken Any Action to This Point?

    We issued a proposal to amend part 39 of the Federal Aviation 
Regulations (14 CFR part 39) to include an AD that would apply to 
certain Pilatus Models PC-12 and PC-12/45 airplanes. This proposal was 
published in the Federal Register as a notice of proposed rulemaking 
(NPRM) on March 5, 2001 (66 FR 13271). The NPRM proposed to supersede 
AD 99-17-08, Amendment 39-11256 (64 FR 45149, August 19, 1999). The 
NPRM also proposed to require you to modify the generator 2 excitation 
by removing certain diodes and installing a new 5-amp circuit breaker 
and suppression filter of improved design in accordance with revised 
procedures.

Was the Public Invited To Comment?

    Interested persons were afforded an opportunity to participate in 
the making of this amendment. No comments were received on the proposed 
rule or the FAA's determination of the cost to the public.

FAA's Determination

What Is FAA's Final Determination on This Issue?

    After careful review of all available information related to the 
subject

[[Page 30301]]

presented above, we have determined that air safety and the public 
interest require the adoption of the rule as proposed except for minor 
editorial corrections. We determined that these minor corrections:

--Will not change the meaning of the AD; and
--Will not add any additional burden upon the public than was already 
proposed.

Cost Impact

How Many Airplanes Does This AD Impact?

    We estimate that this AD affects 69 airplanes in the U.S. registry.

What Is the Cost Impact of This AD on Owners/Operators of the Affected 
Airplanes?

    We estimate the following costs to do the modification of the 
generator 2 excitation:

----------------------------------------------------------------------------------------------------------------
                                                                                Total cost  per   Total cost on
                Labor cost                              Parts cost                  airplane      U.S. operators
----------------------------------------------------------------------------------------------------------------
8 workhours  x  $60 per hour = $480.......  Parts will be provided at no cost             $480          $33,120
                                             to the owners/operators of the
                                             affected aircraft.
----------------------------------------------------------------------------------------------------------------

    If the modification of the generator 2 excitation has been done 
with the manufacturer's modification kit, then we estimate the 
following costs to remove the A250 voltage spike suppression filter and 
replace it with the new A250 voltage spike suppression filter:

----------------------------------------------------------------------------------------------------------------
                                                                                Total cost  per   Total cost  on
                Labor cost                              Parts cost                  airplane     U.S.  operators
----------------------------------------------------------------------------------------------------------------
3 workhours  x  $60 per hour = $180.......  Parts will be provided at no cost             $180          $12,420
                                             to the owners/operators of the
                                             affected aircraft.
----------------------------------------------------------------------------------------------------------------

Regulatory Impact

Does This AD Impact Various Entities?

    The regulations adopted herein will not have a substantial direct 
effect 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, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.

Does This AD Involve a Significant Rule or Regulatory Action?

    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) 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 final evaluation prepared for this 
action is contained 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, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, under 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. FAA amends Sec. 39.13 by removing airworthiness directive (AD) 
99-17-08, Amendment 39-11256 (64 FR 45149, August 19, 1999), and by 
adding a new AD to read as follows:

2001-11-02  Pilatus Aircraft Ltd.: Amendment 39-12243; Docket No. 
99-CE-82-AD, Supersedes AD 99-17-08, Amendment 39-11256.

    (a) What airplanes are affected by this AD? This AD affects 
Models PC-12 and PC-12/45 airplanes, serial numbers 101 through 289, 
that are certificated in any category.
    (b) Who must comply with this AD? Anyone who wishes to operate 
any of the above airplanes must comply with this AD.
    (c) What problem does this AD address? The actions specified by 
this AD are intended to prevent damage to electrical components if 
generator 2 is not switched off before engine shutdown and it 
overheats. This could result in loss of electrical power to certain 
critical airplane components.
    (d) What actions must I accomplish to address this problem? To 
address this problem, you must accomplish the following:

------------------------------------------------------------------------
           Actions                 Compliance            Procedures
------------------------------------------------------------------------
(1) Modify the generator 2    Within the next 100   Do this action
 excitation with the           hours time-in-        following the
 modification kit, part        service (TIS) after   ACCOMPLISHMENT
 number (P/N) 500.50.12.192,   July 23, 2001 (the    INSTRUCTIONS
 which requires you to:        effective date of     section of Pilatus
(i) Remove certain diodes;     this AD), unless      Service Bulletin
(ii) Install a new 5-ramp      already done.         No. 24-012, dated
 circuit breaker, P/N                                February 19, 1999,
 972.55.18.406; and                                  and Service
(iii) Install an A250                                Bulletin No. 24-
 voltage spike suppression                           014, dated October
 filter, P/N 524.52.12.502,                          27, 1999.
 which replaces P/N
 524.52.358
------------------------------------------------------------------------

[[Page 30302]]

 
(2) If the modification kit,  Within the next 100   Do this action
 part number 500.50.12.192,    hours TIS after       following the
 is already installed using    July 23, 2001 (the    ACCOMPLISHMENT
 the A250 voltage spike        effect date of this   INSTRUCTIONS
 suppression filter, part      AD), unless already   section of Pilatus
 number 524.52.12.358,         done.                 Service Bulletin
 replace only this voltage                           No. 24-014, dated
 spike suppression filter                            October 27, 1999.
 with a new A250 voltage
 spike suppression filter,
 part number 524.52.12.502.
(3) Do not install any A250   As of July 23, 2001   Not Applicable.
 voltage spike suppression     (the effective date
 filter, part number           of this AD).
 524.52.358, or FAA-approved
 equivalent part number.
------------------------------------------------------------------------

    (e) Can I comply with this AD in any other way? You may use an 
alternative method of compliance or adjust the compliance time if:
    (1) Your alternative method of compliance provides an equivalent 
level of safety; and
    (2) The Manager, Small Airplane Directorate, approves your 
alternative. Submit your request through an FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Small Airplane Directorate.
    (3) Alternative methods of compliance that were approved in 
accordance with AD 99-17-08 are not considered approved as 
alternative methods of compliance for this AD.

    Note 1: This AD applies to each airplane identified in paragraph 
(a) of this AD, 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 you have not eliminated the unsafe condition, specific 
actions you propose to address it.

    (f) Where can I get information about any already-approved 
alternative methods of compliance? Contact Doug Rudolph, Aerospace 
Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, 
Kansas City, Missouri 64106; telephone: (816) 329-4059; facsimile: 
(816) 329-4090.
    (g) What if I need to fly the airplane to another location to 
comply with this AD? The FAA can issue a special flight permit under 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate your airplane to a location where 
you can accomplish the requirements of this AD.
    (h) Are any service bulletins incorporated into this AD by 
reference? Actions required by this AD must be done in accordance 
with Pilatus Service Bulletin No. 24-012, dated February 19, 1999, 
and Pilatus Service Bulletin No. 24-014, dated October 27, 1999.
    (1) The Director of the Federal Register approved this 
incorporation by reference of Pilatus Service Bulletin No. 24-014, 
dated October 27, 1999, under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) The Director of the Federal Register previously approved 
incorporation by reference of Pilatus Service Bulletin No. 24-012, 
dated February 19, 1999, as of October 4, 1999 (64 FR 45149, August 
19, 1999).
    (3) You can get copies from Pilatus Aircraft Ltd., Customer 
Liaison Manager, CH-6371 Stans, Switzerland. You can look at copies 
at the FAA, Central Region, Office of the Regional Counsel, 901 
Locust, Room 506, Kansas City, Missouri, or at the Office of the 
Federal Register, 800 North Capitol Street, NW, suite 700, 
Washington, DC.
    (i) When does this amendment become effective? This amendment 
becomes effective on July 23, 2001.

    Note 2: The subject of this AD is addressed in Swiss AD Numbers 
HB 99-143, dated February 19, 1999, and HB 99-542, dated October 29, 
1999.


    Issued in Kansas City, Missouri, on May 22, 2001.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 01-13580 Filed 6-5-01; 8:45 am]
BILLING CODE 4910-13-P

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