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

[Federal Register Volume 65, Number 107 (Friday, June 2, 2000)]
[Rules and Regulations]
[Pages 35270-35272]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-13874]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-CE-36-AD; Amendment 39-11762; AD 2000-11-14]
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 document adopts a new airworthiness directive (AD) that 
applies to all Pilatus Aircraft Ltd. (Pilatus) Models PC-12 and PC-12/
45 airplanes that are equipped with pneumatic deicing boots. This AD 
requires you to revise the Airplane Flight Manual (AFM) to include 
requirements for activation of the airframe pneumatic deicing boots. 
This AD is the result of reports of in-flight incidents and an accident 
(on airplanes other than the affected Pilatus airplanes) that occurred 
in icing conditions where the airframe pneumatic deicing boots were not 
activated. The Pilatus Models PC-12 and PC-12/45 airplanes have a 
similar type design (as it relates to airframe pneumatic ice boots) to 
the incident and accident airplanes. The actions specified by this AD 
are intended to assure that flightcrews activate the pneumatic wing and 
tail deicing boots at the first signs of ice accumulation. This action 
will prevent reduced controllability of the aircraft due to adverse 
aerodynamic effects of ice adhering to the airplane prior to the first 
deicing cycle.

EFFECTIVE DATE: July 17, 2000.

ADDRESSES: You may examine information related to this AD at the 
Federal Aviation Administration (FAA), Central Region, Office of the 
Regional Counsel, Attention: Rules Docket No. 99-CE-36-AD, 901 Locust, 
Room 506, Kansas City, Missouri 64106.

FOR FURTHER INFORMATION CONTACT: Mr. John P. Dow, Sr., Aerospace 
Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 506, Kansas 
City, Missouri 64106; telephone: (816) 329-4121; facsimile: (816) 329-
4090.

SUPPLEMENTARY INFORMATION:

Events Leading to the Issuance of This AD

What Caused This AD?

    This AD is the result of reports of in-flight incidents and an 
accident (on airplanes other than the affected Pilatus airplanes) that 
occurred in icing conditions where the airframe pneumatic deicing boots 
were not activated. The Pilatus Models PC-12 and PC-12/45 airplanes 
have a similar type design (as it relates to airframe pneumatic ice 
boots) to the incident and accident airplanes.

What Is the Potential Impact If FAA Took No Action?

    The information necessary to activate the pneumatic wing and tail 
deicing boots at the first signs of ice accumulation is critical for 
flight in icing conditions. If we did not take action to include this 
information, flight crews could experience reduced controllability of 
the aircraft due to adverse aerodynamic effects of ice adhering to the 
airplane prior to the first deicing cycle.

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 all 
Pilatus Models PC-12 and PC-12/45 airplanes that are equipped with 
pneumatic deicing boots. This proposal published in the Federal 
Register as a notice of proposed rulemaking (NPRM) on October 8, 1999 
(64 FR 54833). The NPRM proposed to require revising the Limitations 
Section of the AFM to include requirements for activation of pneumatic 
deicing boots at the first indication of ice accumulation on the 
airplane.

Was the Public Invited To Comment?

    The FAA invited interested persons to participate in the making of 
this amendment. Following is a summary of the two comments received 
with FAA's response.

Comment Issue No. 1: Allow the Use of Recent Airplane Flight Manual 
(AFM) Additions

What Is the Commenter's Concern?

    Pilatus requests that FAA allow the operators of the affected 
airplanes to use as an alternative method of compliance the most recent 
information for Section 2, Limitations, of the Pilatus PC12 Airplane 
Flight Manual (AFM). This information is included in Report No.: 01973-
001, page 2-12, Revision 9: September 1, 1999, and includes the 
following language:

    The wing and tail leading edge pneumatic deicing boot system 
must be activated at the first sign of ice formation anywhere on the 
aircraft, or upon annunciation from an ice detector system (if 
installed), whichever occurs first.
    The wing and tail leading edge pneumatic deicing boot system may 
be deactivated only after leaving icing conditions and after the 
aircraft is determined to be clear of ice.

What Is FAA's Response to the Concern?

    We have determined that inserting this report into the Section 2, 
Limitations, of the Pilatus PC12 AFM provides an equivalent level of 
safety to the actions included in the NPRM. Therefore, we are changing 
the AD to include the option of incorporating into the AFM the 
information proposed in the NPRM or Report No.: 01973-001, page 2-12, 
Revision 9: September 1, 1999.

Comment Issue No. 2: Information is Already Included in the Normal 
Procedures Section of the AFM

What Are the Commenter's Concerns?

    The Federal Office for Civil Aviation (FOCA), which is the 
airworthiness authority for Switzerland, believes that the intent of 
this AD is already covered in the Pilatus PC12 AFM. The FOCA's concerns 
are as follows:
    1. The appropriate time to activate the pneumatic deice boots on 
the affected Pilatus airplanes is prior to entry into icing conditions, 
and until the airfoils are free of ice after exiting icing conditions. 
This information is included in Section 4.10 (Normal Procedures) of the 
PC12 AFM;
    2. These instructions are not necessary in the Limitations Section 
of the AFM. The Limitations Section should only include limitations 
relating to speeds, environment (temperatures),

[[Page 35271]]

or system functions (time limits or configurations). Guidance for this 
is in FAA Advisory Circular (AC) 25.1419-1, dated August 18, 1999. 
Paragraph 12(b)(2) of this AC identifies the Procedures Section as the 
proper place for information ``. . . when the ice protection system 
should be activated.''
    The FOCA requests FAA withdraw the NPRM.

What Is FAA's Response to the Concerns?

    We concur that the information is currently in the Normal 
Procedures section of the Pilatus PC12 AFM and that previous guidance 
(advisory circulars) provides information for putting this information 
in such a section. However, section 91.9 of the Federal Aviation 
Regulations (14 CFR 91.9) only mandates the operating limitations 
(Limitations Section): ``no person may operate a civil aircraft without 
complying with the operating limitations specified in the approved 
Airplane or Rotorcraft Flight Manual.''
    Based upon the importance of operating the deice boots at the 
appropriate time, we determined that the information is mandatory. The 
only method FAA has of changing the Limitations Section of an AFM is 
through AD action, provided an unsafe condition is demonstrated.
    Therefore, we do not concur that the NPRM should be withdrawn. We 
are not changing the AD as a result of this comment.

The FAA's Determination

What Is FAA's Final Determination on This Issue?

    After careful review of all available information related to the 
subject presented above, we have determined that air safety and the 
public interest require the adoption of the rule as proposed except for 
the following:
--Including the option of incorporating Report No.: 01973-001, page 2-
12, Revision 9: September 1, 1999, into Section 2, Limitations, of the 
Pilatus PC12 AFM; and
--Minor editorial corrections.

How Does Including This Option and the Minor Editorial Corrections 
Affect the AD?

    We have determined that including the AFM option and the 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 100 airplanes in the U.S. 
registry.

What Is the Cost Impact of the Affected Airplanes on the U.S. Register?

    There is no dollar cost impact. We estimate 1 workhour for you to 
insert the AFM revision. You can accomplish this action if you hold at 
least a private pilot certificate as authorized by section 43.7 of the 
Federal Aviation Regulations (14 CFR 43.7). You must make an entry into 
the aircraft records that shows compliance with this AD, in accordance 
with section 43.9 of the Federal Aviation Regulations (14 CFR 43.9). 
Therefore, the only cost impact of this AD is the time it will take you 
to insert the information into the AFM.

Regulatory Impact

    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.
    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, 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 Section 39.13 is amended by adding a new 
airworthiness directive (AD) to read as follows:

2000-11-14  PILATUS AIRCRAFT LTD.: Amendment 39-11762; Docket No. 
99-CE-36-AD.
    (a) What airplanes are affected by this AD? Models PC-12 and PC-
12/45 airplanes, all serial numbers, that are:
    (1) equipped with pneumatic deicing boots; and
    (2) certificated in any category.
    (b) Who must comply with this AD? Anyone who wishes to operate 
any of the above airplanes on the U.S. Register. The AD does not 
apply to your airplane if it is not equipped with pneumatic de-icing 
boots.
    (c) What problem does this AD address? The information necessary 
to activate the pneumatic wing and tail deicing boots at the first 
signs of ice accumulation is critical for flight in icing 
conditions. If we did not take action to include this information, 
flight crews could experience reduced controllability of the 
aircraft due to adverse aerodynamic effects of ice adhering to the 
airplane prior to the first deicing cycle.
    (d) What must I do to address this problem? To address this 
problem, you must revise the Limitations Section of FAA-approved 
Airplane Flight Manual (AFM) to include the following requirements 
for activation of the ice protection systems. You must accomplish 
this action within the next 10 calendar days after July 17, 2000 
(the effective date of this AD), unless already accomplished. You 
may insert a copy of this AD in the AFM to accomplish this action:
    <bullet> Except for certain phases of flight where the AFM 
specifies that deicing boots should not be used (e.g., take-off, 
final approach, and landing), compliance with the following is 
required.
    <bullet> Wing and Tail Leading Edge Pneumatic Deicing Boot 
System, if installed, must be activated:
--At the first sign of ice formation anywhere on the aircraft, or 
upon annunciation from an ice detector system, whichever occurs 
first; and
--The system must either be continued to be operated in the 
automatic cycling mode, if available; or the system must be manually 
cycled as needed to minimize the ice accretions on the airframe.
    <bullet> The wing and tail leading edge pneumatic deicing boot 
system may be deactivated only after:
--Leaving known or observed/detected icing that the flight crew has 
visually observed on the aircraft or was identified by the on-board 
sensors; and
--After the airplane is determined to be clear of ice.

    Note: The FAA recommends periodic treatment of deicing boots 
with approved ice release agents, such as ICEX<INF>TM</INF>, in 
accordance with the manufacturer's application instructions.

    (e) Have I accomplished the intent of this AD if I have 
incorporated the latest Pilatus PC12 AFM report into Section 2, 
Limitations?

[[Page 35272]]

As an alternative method of compliance to the actions required by 
paragraphs (a), (a)(1), and (a)(2) of this AD, you may incorporate 
Report No.: 01973-001, page 2-12, Revision 9: September 1, 1999, 
into Section 2, Limitations, of the Pilatus PC12 AFM.
    (f) Can the pilot accomplish the action? Anyone who holds at 
least a private pilot certificate, as authorized by section 43.7 of 
the Federal Aviation Regulations (14 CFR 43.7), may incorporate the 
AFM revisions required by this AD. You must make an entry into the 
aircraft records, showing compliance with this AD, in accordance 
with section 43.9 of the Federal Aviation Regulations (14 CFR 43.9).
    (g) 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.

    Note: 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 (g) 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.

    (h) Where can I get information about any already-approved 
alternative methods of compliance? Contact the Small Airplane 
Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; 
telephone: (816) 329-4121; facsimile: (816) 329-4091.
    (i) 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.
    (j) When does this amendment become effective? This amendment 
becomes effective on July 17, 2000.

    Issued in Kansas City, Missouri, on May 24, 2000.
James E. Jackson,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-13874 Filed 6-1-00; 8:45 am]
BILLING CODE 4910-13-U

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