Airworthiness directives: Pilatus Aircraft Ltd.,

[Federal Register: June 23, 1999 (Volume 64, Number 120)]

[Proposed Rules]

[Page 33445-33447]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr23jn99-31]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-CE-119-AD]

RIN 2120-AA64

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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

SUMMARY: This document proposes to adopt a new airworthiness directive (AD) that would apply to certain Pilatus Aircraft Ltd. (Pilatus) Models PC-12 and PC-12/45 airplanes. The proposed AD would require inspecting all flap actuators in the internal gear system to assure that correct end-play and backlash measurements exist, and accomplishing any corrective adjustments as necessary. The proposed AD would also require incorporating a temporary revision into the Pilot's Operating Handbook (POH) in order to update operating procedures for the flap actuators; and would require incorporating temporary revisions to the maintenance manual in order to make the proposed inspection part of the future maintenance program. The proposed AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Switzerland. The actions specified by the proposed AD are intended to prevent premature wear of the internal gear system caused by excessive backlash in the flight control flap actuators, which could eventually result in loss of actuator output with possible reduced or loss of airplane control.

DATES: Comments must be received on or before July 28, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 98-CE-119-AD, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106. Comments may be inspected at this location between 8 a.m. and 4 p.m., Monday through Friday, holidays excepted.

Service information that applies to the proposed AD may be obtained from Pilatus Aircraft Ltd., Customer Liaison Manager, CH-6371 Stans, Switzerland; telephone: +41 41 619 63 19; facsimile: +41 41 610 33 51. This information also may be examined at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT: Mr. Roman T. Gabrys, Aerospace Engineer, FAA, Small Airplane Directorate, 1201 Walnut, suite 900, Kansas City, Missouri 64106; telephone: (816) 426-6932; facsimile: (816) 426-2169.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed 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, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed 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 proposal will be filedin the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket No. 98-CE-119-AD.'' The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 98-CE-119-AD, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.

Discussion

The Federal Office for Civil Aviation (FOCA), which is the airworthiness authority for Switzerland, recently notified the FAA that an unsafe condition may exist on certain Pilatus Models PC-12 and PC- 12/45 airplanes. The FOCA of Switzerland reports excessive backlash found in the flap actuators of the internal gear system. Excessive backlash will lead to premature wear of the gear.

This condition, if not detected and corrected, could result in internal failure of the internal gear system with loss of actuator output and possible reduced or loss of airplane control.

Relevant Service Information

Pilatus has issued Service Bulletin No. 27-005, November 18, 1998, which specifies procedures for:

--Inspecting all flap actuators in the internal gear system to assure that correct end-play and backlash measurements exist; --Incorporating both Temporary Revision No. 27-04, and Temporary Revision No. 04-01, both dated November 18, 1998; into the Pilatus PC- 12 Maintenance Manual; and --Incorporating PC-12 Pilot's Operating Handbook, Pilatus Report No. 01973-001, Temporary Revision No. 4, Flap Actuators, dated November 18, 1998.

The FOCA of Switzerland classified this service bulletin as mandatory and issued Swiss AD HB 98-460, dated November 23, 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.

[[Page 33446]]

The FAA has examined the findings of the FOCA of Switzerland; reviewed all available information, including the service information referenced above; 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 the Proposed AD

Since an unsafe condition has been identified that is likely to exist or develop in other Pilatus PC-12 and PC-12/45 airplanes of the same type design that incorporate a certain flight control flap actuator and that are registered in the United States, the FAA is proposing AD action. The proposed AD would require inspecting all flap actuators in the internal gear system to assure that correct end-play and backlash measurements exist, and accomplishing any corrective adjustments as necessary. The proposed AD would also require incorporating the temporary revision into the POH in order to update operating procedures for the flap actuators; and would require incorporating temporary revisions to the maintenance manual in order to make the proposed inspection part of the future maintenance program.

The affected airplanes could incorporate one of the following flight control flap actuators:

--Pilatus part number (P/N) 978.71.20.302--Actuator, Linear (951D100- 5); --Pilatus P/N 978.71.20.303--Actuator, Linear (951D100-7); and --Pilatus P/N 978.71.20.304--Actuator, Linear (951D100-9).

Accomplishment of the proposed inspection would be in accordance with Pilatus Service Bulletin No. 27-005, November 18, 1998. The proposed adjustments, if necessary, would be accomplished in accordance with the maintenance manual.

Cost Impact

The FAA estimates that 69 airplanes in the U.S. registry would be affected by the proposed AD, that it would take approximately 6 workhours per airplane to accomplish the proposed action, and that the average labor rate is approximately $60 an hour. The manufacturer will provide parts free-of-charge to the owners/operators of the affected aircraft. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $24,840, or $360 per airplane.

Incorporating the proposed POH and maintenance manual revisions 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 the proposed AD in accordance with section 43.9 of the Federal Aviation Regulations (14 CFR 43.9). The only cost impact the proposed POH and maintenance manual revision requirements impose is the time it would take each owner/operator of the affected airplanes to incorporate this information into the POH and maintenance manual.

Regulatory Impact

The regulations proposed herein would 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 proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

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) if promulgated, 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 draft regulatory evaluation prepared for this action has been placed 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.

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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 adding a new airworthiness directive (AD) to read as follows:

   Pilatus Aircraft LtD.: Docket No. 98-CE-119-AD.

   Applicability: Models PC-12 and PC-12/45 airplanes, manufacturer serial numbers (MSN) 101 through MSN 236; certificated in any category, that have one of the following flight control flap actuators installed:

   --Pilatus part number (P/N) 978.71.20.302--Actuator, Linear (951D100-5); --Pilatus P/N 978.71.20.303--Actuator, Linear (951D100-7); and --Pilatus P/N 978.71.20.304-- Actuator, Linear (951D100-9).

   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 premature wear of the internal gear system caused by excessive backlash in the flight control flap actuators, which could eventually result in loss of actuator output with possible reduced or loss of airplane control, accomplish the following:

   (a) Within the next 50 hours time-in-service (TIS) after the effective date of this AD, inspect all flap actuators in the internal gear system to assure that correct end-play and backlash measurements exist, in accordance with the ACCOMPLISHMENT INSTRUCTIONS section of Pilatus Service Bulletin No. 27-005, November 18, 1998. Prior to further flight, perform any corrective adjustments, as necessary, in accordance with the maintenance manual.

   (b) As of the effective date of this AD, no person may install, on any airplane, a flap actuator that has not been inspected and adjusted (as necessary) as required by paragraph (a) this AD.

   (c) Prior to further flight after the inspection and possible modification required by paragraph (a) of this AD, accomplish the following:

   (1) Insert Pilatus Report No. 01973-001, Temporary Revision No. 4, Flap Actuators, dated November 18, 1998, into the Pilot's Operating Handbook (POH).

   (2) Insert Temporary Revision No. 27-04, and Temporary Revision No. 04-01, both dated November 18, 1998; into the Pilatus PC-12 Maintenance Manual.

   (d) Accomplishment of the POH revision and maintenance manual insertions, as required by paragraph (c) of this AD, may be

   [[Page 33447]]

   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).

   (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 times that provides an equivalent level of safety may be approved by the Manager, Small Airplane Directorate, 1201 Walnut, suite 900, Kansas City, Missouri 64106. 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.

   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 related to Pilatus Service Bulletin No. 27-005, dated November 18, 1998, should be directed to Pilatus Aircraft Ltd., Customer Liaison Manager, CH-6371 Stans, Switzerland; telephone: +41 41 619 63 19; facsimile: +41 41 610 33 51. 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.

   Note 3: The subject of this AD is addressed in Swiss AD HB 98- 460, dated November 23, 1998.

   Issued in Kansas City, Missouri, on June 16, 1999. Michael Gallagher, Manager, Small Airplane Directorate, Aircraft Certification Service.

   [FR Doc. 99-15927Filed6-22-99; 8:45 am]

   BILLING CODE 4910-13-U