2023-03924. Airworthiness Directives; Pilatus Aircraft Ltd. Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for certain Pilatus Aircraft Ltd. (Pilatus) Model PC-12, PC-12/45, PC-12/47, and PC-12/47E airplanes. This proposed AD was prompted by mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI identifies the unsafe condition as insufficient grounding of the vapor cycle cooling system (VCCS) compressor/condenser. This proposed AD would require inspecting the power return and chassis grounding cable attachment points at frame 37, including the attachment parts, and depending on the inspection results, corrective action. This proposed AD would also require modifying the installation of the VCCS compressor/condenser power return cables and installing an additional isolated VCCS chassis ground cable. The FAA is proposing this AD to address the unsafe condition on these products.

DATES:

The FAA must receive comments on this NPRM by April 13, 2023.

ADDRESSES:

You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods:

• Federal eRulemaking Portal: Go to regulations.gov. Follow the instructions for submitting comments.

• Fax: [phone].

• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.

• Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2023-0421; or in person at Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this NPRM, the MCAI, any comments received, and other information. The street address for Docket Operations is listed above.

Material Incorporated by Reference:

• For service information identified in this NPRM, contact Pilatus Aircraft Ltd., Customer Support General Aviation, CH-6371 Stans, Switzerland; phone: [phone]; email: [e-mail]; website: pilatus-aircraft.com.

• You may view this service information at the FAA, Airworthiness Products Section, Operational Safety Branch, 901 Locust, Kansas City, MO 64106. For information on the availability of this material at the FAA, call [phone].

FOR FURTHER INFORMATION CONTACT:

Doug Rudolph, Aviation Safety Engineer, General Aviation & Rotorcraft Section, International Validation Branch, FAA, 901 Locust, Room 301, Kansas City, MO 64106; phone: [phone]; email: [e-mail].

SUPPLEMENTARY INFORMATION:

Comments Invited

The FAA invites you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under ADDRESSES . Include “Docket No. FAA-2023-0421; Project Identifier MCAI-2022-01360-A” at the beginning of your comments. The most helpful comments reference a specific portion of the proposal, explain the reason for any recommended change, and include supporting data. The FAA will consider all comments received by the closing date and may amend this proposal because of those comments.

Except for Confidential Business Information (CBI) as described in the following paragraph, and other information as described in 14 CFR 11.35, the FAA will post all comments received, without change, to regulations.gov, including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this NPRM.

Confidential Business Information

CBI is commercial or financial information that is both customarily and actually treated as private by its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public disclosure. If your comments responsive to this NPRM contain commercial or financial information that is customarily treated as private, that you actually treat as private, and that is relevant or responsive to this NPRM, it is important that you clearly designate the submitted comments as CBI. Please mark each page of your submission containing CBI as “PROPIN.” The FAA will treat such marked submissions as confidential under the FOIA, and they will not be placed in the public docket of this NPRM. Submissions containing CBI should be sent to Doug Rudolph, Aviation Safety Engineer, FAA, General Aviation & Rotorcraft Section, International Validation Branch, 901 Locust, Room 301, Kansas City, MO 64106. Any commentary that the FAA receives which is not specifically designated as CBI will be placed in the public docket for this rulemaking.

Background

The European Union Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2022-0212, dated October 18, 2022 (referred to after this as “the MCAI”), to correct an unsafe condition on certain serial-numbered Pilatus Model PC-12, PC-12/45, PC-12/47, and PC-12/47E airplanes.

The MCAI was prompted by a reported occurrence of a burning odor coming from the air conditioning vents during the climb phase of a Pilatus Model PC-12/47E airplane. An investigation identified that insufficient grounding of the VCCS compressor/condenser at frame 37 resulted in severe heat damage to the baseplate and adjacent metal support structure. It was determined that this condition may occur on airplanes equipped in production with the large oxygen bottle installed on the right-hand side of the rear fuselage.

To address the unsafe condition, the MCAI requires a one-time inspection of the power return and chassis grounding cable attachment point at frame 37, including the attachment parts, and modification of the installation of the VCCS.

This condition, if not addressed, could, in the case of damage to the oxygen supply line, lead to an uncontrolled fire with damage to the airplane and injury to the occupants.

You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2023-0421.

Related Service Information Under 1 CFR Part 51

The FAA reviewed Pilatus PC-12 Service Bulletin 21-016, dated August 15, 2022, which specifies procedures for inspecting the power return and chassis grounding cable attachment point on the airframe at frame 37, including the attachment parts, modifying the installation of the VCCS compressor/condenser power return cables, and installing an additional isolated VCCS chassis ground cable. This service bulletin also specifies contacting Pilatus if any damage is found.

This service information is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in ADDRESSES .

FAA's Determination

These products have been approved by the aviation authority of another country and are approved for operation in the United States. Pursuant to the FAA's bilateral agreement with this State of Design Authority, it has notified the FAA of the unsafe condition described in the MCAI and service information described above. The FAA is issuing this NPRM after determining that the unsafe condition described previously is likely to exist or develop on other products of these same type designs.

Proposed AD Requirements in This NPRM

This proposed AD would require accomplishing the actions specified in the MCAI, except as discussed under “Differences Between this Proposed AD and the MCAI.”

Differences Between This Proposed AD and the MCAI

The MCAI requires contacting the manufacturer for approved corrective action instructions if any discrepancy is found during the inspection. This proposed AD would require contacting either the Manager, International Validation Branch, FAA; or EASA; or Pilatus's EASA Design Organization Approval (DOA). If approved by the DOA, the approval must include the DOA-authorized signature.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would affect 8 airplanes of U.S. registry.

The FAA estimates the following costs to comply with this proposed AD:

Estimated Costs

Action	Labor cost	Parts cost	Cost per product	Cost on U.S. operators
Inspect	3 work-hours × $85 per hour = $255	Not Applicable	$255	$2,040
Modify	5 work-hours × $85 per hour = $425	667	1,092	8,736

The repair instructions that may be needed as a result of the inspection could vary significantly from airplane to airplane. The FAA has no data to determine the costs to accomplish the repair or the number of airplanes that would need this repair.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII: Aviation Programs, describes in more detail the scope of the Agency's authority.

The FAA is issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701: General requirements. Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

Regulatory Findings

The FAA determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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.

For the reasons discussed above, I certify this proposed regulation:

(1) Is not a “significant regulatory action” under Executive Order 12866,

(2) Would not affect intrastate aviation in Alaska, and

(3) Would not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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.

§ 39.13

[Amended]

2. The FAA amends § 39.13 by adding the following new airworthiness directive:

Pilatus Aircraft Ltd.: Docket No. FAA-2023-0421; Project Identifier MCAI-2022-01360-A.

(a) Comments Due Date

The FAA must receive comments on this airworthiness directive (AD) by April 13, 2023.

(b) Affected ADs

None.

(c) Applicability

This AD applies to Pilatus Aircraft Ltd. Model PC-12, PC-12/45, PC-12/47, and PC-12/47E airplanes, serial numbers 466, 467, 725, 861, 1032, 1052, 1082, 1115, 1232, 1411, 1428, 1439, 1530, 1541, 1663, 1725, and 1802, certificated in any category.

(d) Subject

Joint Aircraft System Component (JASC) Code 2197, Air Conditioning System Wiring.

(e) Unsafe Condition

This AD was prompted by mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI identifies the unsafe condition as insufficient grounding of the vapor cycle cooling system (VCCS) compressor/condenser. The FAA is issuing this AD to address this condition. The unsafe condition, if not addressed, could, in the case of damage to the oxygen supply line, lead to an uncontrolled fire with damage to the airplane, and injury to the occupants.

(f) Compliance

Comply with this AD within the compliance times specified, unless already done.

(g) Required Actions

(1) Within 2 months after the effective date of this AD, inspect the power return and chassis grounding cable attachment points at frame 37, including the attachment parts, for physical and heat damage, de-lamination, and corrosion in accordance with steps (2) through (6) of Section 3.B. of the Accomplishment Instructions in Pilatus PC-12 Service Bulletin (SB) 21-016, dated August 15, 2022 (Pilatus PC-12 SB 21-016).

(2) If, during the inspection required by paragraph (g)(1) of this AD, any physical or heat damage, de-lamination, or corrosion as identified in steps (2) through (6) of Section 3.B. of the Accomplishment Instructions in Pilatus PC-12 SB 21-016 is detected, before further flight, repair using a method approved by the Manager, International Validation Branch, FAA; the European Union Aviation Safety Agency (EASA); or Pilatus's EASA Design Organization Approval (DOA). If approved by the DOA, the approval must include the DOA-authorized signature.

(3) Within 2 months after the effective date of this AD, modify the installation of the VCCS compressor/condenser power return cables and install an additional isolated VCCS chassis ground cable in accordance with Section 3.C. of the Accomplishment Instructions in Pilatus PC-12 SB 21-016. Where the service bulletin specifies discarding the stop angle, this AD requires removing the stop angle from service.

(h) Alternative Methods of Compliance (AMOCs)

The Manager, International Validation Branch, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in § 39.19. In accordance with § 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the manager of the International Validation Branch, mail it to the address identified in paragraph (i)(2) of this AD or email to: [e-mail]. If mailing information, also submit information by email. Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office.

(i) Additional Information

(1) Refer to EASA AD 2022-0212, dated October 18, 2022, for related information. This EASA AD may be found in the AD docket at regulations.gov under Docket No. FAA-2023-0421.

(2) For more information about this AD, contact Doug Rudolph, Aviation Safety Engineer, General Aviation & Rotorcraft Section, International Validation Branch, FAA, 901 Locust, Room 301, Kansas City, MO 64106; phone: [phone]; email: [e-mail].

(j) Material Incorporated by Reference

(1) The Director of the Federal Register approved the incorporation by reference of the service information listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) You must use this service information as applicable to do the actions required by this AD, unless the AD specifies otherwise.

(i) Pilatus PC-12 Service Bulletin 21-016, dated August 15, 2022.

(ii) [Reserved]

(3) For service information identified in this AD, contact Pilatus Aircraft Ltd., Customer Support General Aviation, CH-6371 Stans, Switzerland; phone: [phone]; email: [e-mail]; website: pilatus-aircraft.com.

(4) You may view this service information at the FAA, Airworthiness Products Section, Operational Safety Branch, 901 Locust, Kansas City, MO 64106. For information on the availability of this material at the FAA, call [phone].

(5) You may view this service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, email [e-mail], or go to: www.archives.gov/​federal-register/​cfr/​ibr-locations.html.

Issued on February 17, 2023.

Christina Underwood,

Acting Director, Compliance & Airworthiness Division, Aircraft Certification Service.