2021-26544. Airworthiness Directives; Pilatus Aircraft Ltd. Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule.

SUMMARY:

The FAA is adopting a new airworthiness directive (AD) for Pilatus Aircraft Ltd. (Pilatus) Model PC-12/45, PC-12/47, and PC-12/47E airplanes with Supplemental Type Certificate (STC) SA00634DE installed. This AD was prompted by a report of strake attachment brackets and the fuselage frame failing at the upper most bracket attachment location. This AD requires inspecting the strake, attachment brackets, surrounding structure, and bolts and replacing components and repairing damage if necessary. The FAA is issuing this AD to address the unsafe condition on these products.

DATES:

This AD is effective January 13, 2022.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of January 13, 2022.

ADDRESSES:

For service information identified in this final rule, contact Pilatus Business Aircraft Ltd., Customer Support Department, 12300 Pilatus Way, Broomfield, CO 80021; phone: [phone]; fax: [phone]; email: [e-mail]. 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]. It is also available at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-0573.

Examining the AD Docket

You may examine the AD docket at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-0573; 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 final rule, any comments received, and other information. The address for Docket Operations is U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT:

Richard R. Thomas, Aviation Safety Engineer, Denver ACO Branch, FAA, 26805 E 68th Avenue, Denver, CO 80249; phone: [phone]; fax: [phone]; email: [e-mail].

SUPPLEMENTARY INFORMATION:

Background

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to Pilatus Aircraft Ltd. Model PC-12/45, PC-12/47, and PC-12/47E airplanes with STC SA00634DE installed. The NPRM published in the Federal Register on July 22, 2021 (86 FR 38613). The NPRM was prompted by a report of strake attachment brackets and the fuselage frame failing at the upper most bracket attachment location. In the NPRM, the FAA proposed to require inspecting the strake, attachment brackets, and bolts for movement and damage, both internal and external, and replacing components and repairing damage if necessary. The FAA is issuing this AD to prevent buffeting of the strakes. This condition, if not addressed, could result in airplane flutter and reduced lateral stability, which may lead to loss of control of the airplane.

Discussion of Final Airworthiness Directive

Comments

The FAA received no comments on the NPRM or on the determination of the costs.

Differences Between the NPRM and the Final Rule

The FAA has clarified the wording of the required inspections in paragraph (g) of this AD. This is not a substantive change.

Conclusion

The FAA reviewed the relevant data and determined that air safety requires adopting this AD as proposed. Accordingly, the FAA is issuing this AD to address the unsafe condition on these products. Except for the changes described previously, this AD is adopted as proposed in the NPRM. None of the changes will increase the economic burden on any operator.

Related Service Information Under 1 CFR Part 51

The FAA reviewed Pilatus Service Bulletin PC-12 Series, Report Number 12-1700-64-0000, Revision B, dated August 10, 2018 (Pilatus Report 12-1700-64-0000B), which contains procedures for inspection of all fuselage strake attachment bolts and the surrounding structure. 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 .

Differences Between This AD and the Service Information

Pilatus Report 12-1700-64-0000B specifies a one-time inspection within 10 flight hours of issuance of the service bulletin and recommends repeat inspections without specifying an inspection interval. This AD requires repeating the inspection every 150 flight hours. Pilatus Report 12-1700-64-0000B specifies contacting Pilatus for further instructions. This AD requires using an FAA-approved repair method. Pilatus Report 12-1700-64-0000B applies to Pilatus PC-12 aircraft serial numbers 190 to 1575. This AD applies to all Pilatus Aircraft Ltd. Models PC-12/45, PC-12/47, and PC-12/47E airplanes, regardless of serial number, if STC SA00634DE is installed.

Interim Action

The FAA considers this AD an interim action. Pilatus is working on a modification with the intent of minimizing, if not eliminating, the buffeting of the strakes. Once this action is developed, approved, and available, the FAA may consider additional rulemaking.

Costs of Compliance

The FAA estimates that this AD affects 30 airplanes of U.S. registry.

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

Estimated Costs

Action	Labor cost	Parts cost	Cost per product	Cost on U.S. operators
Inspection of the strake assemblies	1 work-hour × $85 per hour = $85 per inspection cycle	Not applicable	$85 per inspection cycle	$2,550 per inspection cycle.

The extent of damage found during the proposed inspections may vary considerably from airplane to airplane. The FAA has no way of knowing how many airplanes may have damage or the extent of damage each airplane may have.

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

This AD will not have federalism implications under Executive Order 13132. This AD 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.

For the reasons discussed above, I certify that this AD:

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

(2) Will not affect intrastate aviation in Alaska, 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.

List of Subjects in 14 CFR Part 39

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

The Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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:

2021-24-01 Pilatus Aircraft Ltd.: Amendment 39-21822; Docket No. FAA-2021-0573; Project Identifier 2018-CE-046-AD.

(a) Effective Date

This airworthiness directive (AD) is effective January 13, 2022.

(b) Affected ADs

None.

(c) Applicability

This AD applies to Pilatus Aircraft Ltd. (Pilatus) Model PC-12/45, PC-12/47, and PC-12/47E airplanes, all serial numbers, certificated in any category, with a Spectre Lift Platform System installed in accordance with Supplemental Type Certificate No. SA00634DE.

(d) Subject

Joint Aircraft System Component (JASC) Code 5350, Aerodynamic Faring.

(e) Unsafe Condition

This AD was prompted by a report of the strake attachment brackets and surrounding structure failing at the upper most bracket bolt hole. The FAA is issuing this AD to detect and address any looseness or damage to the strake, attachment brackets, or surrounding structure, and missing fasteners or loose bolts, which could result in airplane flutter and reduced lateral stability, which may lead to loss of control of the airplane.

(f) Compliance

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

(g) Inspection and Corrective Actions

Within 10 hours time-in-service (TIS) after the effective date of this AD and thereafter at intervals not to exceed 150 hours TIS, inspect the fuselage strakes for movement (outside inspection), the strakes and their attachment brackets for loose and missing bolts and screws and structural deformation (inside and outside inspection), and the strake attachment brackets and surrounding structure for discoloration, deformation, cracks, and other structural damage (inside inspection) by following the Accomplishment Instructions—Aircraft, steps A through B.(3) and C.(1) through C.(5), in Pilatus Service Bulletin PC-12 Series, Report Number 12-1700-64-0000, Revision B, dated August 10, 2018.

(1) You must accomplish the inside fuselage inspection regardless of the results of the outside fuselage inspection.

(2) If any movement of the strakes, a loose or missing bolt or screw, discoloration, deformation, a crack, or other structural damage is found during any of the inspections, before further flight, repair using FAA-approved procedures.

(h) Special Flight Permit

A special flight permit may be issued to allow flying the airplane to a maintenance facility where repair of the strake assembly will be performed with the following operating limitations:

(1) Flight must be conducted under visual flight rules, daytime only; and

(2) The Spectre Lift Platform System, STC SA00634DE, must be retracted (not deployed) during the flight.

(i) Alternative Methods of Compliance (AMOCs)

(1) The Manager, Denver ACO Branch, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 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 certification office, send it to the attention of the person identified in paragraph (j) of this AD.

(2) 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.

(j) Related Information

For more information about this AD, contact Richard R. Thomas, Aviation Safety Engineer, Denver ACO Branch, FAA, 26805 E. 68th Avenue, Denver, CO 80249; phone: [phone]; fax: [phone]; email: [e-mail].

(k) Material Incorporated by Reference

(1) The Director of the Federal Register approved the incorporation by reference (IBR) 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 Service Bulletin PC-12 Series, Report Number 12-1700-64-0000, Revision B, dated August 10, 2018.

(ii) [Reserved]

(3) For service information identified in this AD, contact Pilatus Business Aircraft Ltd., Customer Support Department, 12300 Pilatus Way, Broomfield, CO 80021; phone: [phone]; fax: [phone]; email: [e-mail].

(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: https://www.archives.gov/​federal-register/​cfr/​ibr-locations.html.

Issued on December 2, 2021.

Lance T. Gant,

Director, Compliance & Airworthiness Division, Aircraft Certification Service.