Airworthiness Directives; Pilatus Aircraft Ltd. Models PC-7, PC-12, and PC-12/45 Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule.

SUMMARY:

This amendment adopts a new airworthiness directive (AD) that applies to all Pilatus Aircraft Ltd. Models PC-7, PC-12, and PC-12/45 airplanes that incorporate a certain engine-driven pump. This AD requires you to inspect the joints between the engine-driven pump housing, relief valve housing, and the relief-valve cover for signs of fuel leakage or extruding gasket material; replace any engine-driven pump with signs of fuel leakage or extruding gasket material; and inspect to ensure that the relief valve attachment screws are adequately torqued and re-torque as necessary. 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 detect and correct gasket material extruding from the engine-driven pump housing and detect and correct relief valve attachment screws with inadequate torque. Such conditions could lead to fuel leakage and result in a fire in the engine compartment.

DATES:

This AD becomes effective on February 28, 2002.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in the regulations as of February 28, 2002.

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 63 19; facsimile: +41 41 619 6224; or from Pilatus Business Aircraft Ltd., Product Support Department, 11755 Airport Way, Broomfield, Colorado 80021; telephone: (303) 465-9099; facsimile: (303) 465-6040. You may view this information at the Federal Aviation Administration (FAA), Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2001-CE-33-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

What Events Have Caused This AD?

The Federal Office for Civil Aviation (FOCA), which is the airworthiness authority for Switzerland, recently notified FAA of an unsafe condition that may exist on Pilatus Models PC-7, PC-12, and PC-12/45 airplanes. The FOCA reports instances of fuel leaking from the engine-driven pump on the referenced airplanes. The compression set of the gasket and diaphragm after thermal cycling could cause the gasket of the engine-driven pump to extrude between the relief valve housing and the engine-driven pump housing. This in turn relieves the torque of the relief-valve cover screws of the engine-driven pump, which could result in fuel leakage.

Information on the affected pumps follows:

—The affected engine-driven pumps are Lear Romec part number RG9570R1 (Pilatus part number 968.84.51.106) as installed on Models PC-12 and PC-12/45 airplanes or Lear Romec part number RG9570M1 (Pilatus part number 968.84.51.105) as installed on Model PC-7 airplanes;

—Pilatus installed these engine-driven pumps on manufacturer serial number (MSN) 101 through MSN 400 of the Models PC-12 and PC-12/45 airplanes and MSN 101 through MSN 618 of the Model PC-7 airplanes; and

—These engine-driven pumps could be installed through field approval on any MSN of the Models PC-7, PC-12, and PC-12/45 airplanes.

What Is the Potential Impact if FAA Took No Action?

Gasket material extruding from the engine-driven pump housing and relief valve attachment screws with inadequate torque, if not detected and corrected, could lead to fuel leakage and result in a fire in the engine compartment.

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 Aircraft Ltd. Models PC-7, PC-12, and PC-12/45 airplanes that incorporate a certain engine-driven pump. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on October 24, 2001 (66 FR 53738). The NPRM proposed to require you to inspect the joints between the engine-driven pump housing, relief valve housing, and the relief-valve cover for signs of fuel leakage or extruding gasket material; replace any engine-driven pump with signs of fuel leakage or extruding gasket material; and inspect to ensure that the relief valve attachment screws are adequately torqued and re-torque as necessary.

Was the Public Invited To Comment?

The FAA encouraged interested persons to participate in the making of this amendment. We did not receive any comments on the proposed rule or on our 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 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 have determined that these minor corrections:

—Provide the intent that was proposed in the NPRM for correcting the unsafe condition; and

—Do not add any additional burden upon the public than was already proposed in the NPRM.

Cost Impact

How Many Airplanes Does This AD Impact?

We estimate that this AD affects 278 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 accomplish the inspections and re-torque:

We estimate the following costs to accomplish any necessary replacements that will be required based on the results of the inspection. We have no way of determining the number of airplanes that may need such replacement:

Compliance Time of This AD

What Is the Compliance Time of This AD?

The compliance time of the inspections that will be required by this AD is “within 20 hours time-in-service (TIS) after the effective date of this AD or within the next 30 days after the effective date of this AD, whichever occurs first.”

Why Is the Compliance Time of This AD Presented in Both Hours TIS and Calendar Time?

The deterioration and potential extrusion of the gasket occurs over time and is not a condition of repetitive airplane operation. However, the relief valve attachment screws becoming inadequately torqued occurs as a result of airplane usage if the compression set of the gasket and diaphragm after thermal cycling causes the gasket of the engine-driven pump to extrude between the relief valve housing and the engine-driven pump housing.

Therefore, to ensure that the unsafe condition defined in this document is detected and corrected in a timely manner, we are stating the compliance in both calendar time and hours TIS.

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.

2. FAA amends § 39.13 by adding a new AD to read as follows:

2002-01-09 Pilatus Aircraft Ltd.: Amendment 39-12600; Docket No. 2001-CE-33-AD.

(a) What airplanes are affected by this AD? This AD affects the following airplane models and serial numbers that are certificated in any category:

Note 1:

Pilatus installed these engine-driven pumps on manufacturer serial number (MSN) 101 through MSN 400 of the Models PC-12 and PC-12/45 airplanes and MSN 101 through MSN 618 of the Model PC-7 airplanes. These engine-driven pumps could be installed through field approval on any MSN of the Models PC-7, PC-12, and PC-12/45 airplanes.

(b) Who must comply with this AD? Anyone who wishes to operate any of the airplanes identified in paragraph (a) of this AD must comply with this AD.

(c) What problem does this AD address? The actions specified by this AD are intended to detect and correct gasket material extruding from the engine-driven pump housing and detect and correct relief valve attachment screws with inadequate torque. Such conditions could lead to fuel leakage and result in a fire in the engine compartment.

(d) What actions must I accomplish to address this problem? To address this problem, you must accomplish the following:

(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.

Note 2:

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 PC-7 Service Bulletin No. 28-006 or Pilatus PC-12 Service Bulletin No. 28-009, both dated August 10, 2001. The Director of the Federal Register approved this incorporation by reference under 5 U.S.C. 552(a) and 1 CFR part 51. You can get copies from Pilatus Aircraft Ltd., Customer Liaison Manager, CH-6371 Stans, Switzerland; or from Pilatus Business Aircraft Ltd., Product Support Department, 11755 Airport Way, Broomfield, Colorado 80021. 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 February 28, 2002.

Note 3:

The subject of this AD is addressed in Swiss AD HB 2001-500 (PC-12 and PC-12/45) and Swiss AD HB-505 (PC-7), both dated August 24, 2001.