AD 2020-18-05

This AD is effective October 7, 2020.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of October 7, 2020.

For service information identified in this final rule, contact Pratt & Whitney Canada Corp., 1000 Marie-Victorin, Longueuil, Quebec, Canada, J4G 1A1; phone: 800-268-8000; fax: 450-647-2888; website: https://www.pwc.ca/en/. You may view this service information at the FAA, Airworthiness Products Section, Operational Safety Branch, 1200 District Avenue, Burlington, MA 01803. For information on the availability of this material at the FAA, call 781-238-7759. It is also available on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2020-0471.

Mehdi Lamnyi, Aerospace Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: 781-238-7743; fax: 781-238-7199; email: Mehdi.Lamnyi@faa.gov.

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to all P&WC PT6B-37A model turboshaft engines with engine serial number PCE-PU0289 and earlier. The NPRM published in the Federal Register on May 14, 2020 (85 FR 28888). The NPRM was prompted by a report of contamination from galvanic corrosion between the FCU aluminum body and the steel union fitting causing the loss of engine control, resulting in an engine over-speed condition and subsequent IFSD. The NPRM proposed to require replacing the FCU with a part eligible for installation. The FAA is issuing this AD to address the unsafe condition on these products.

Transport Canada Civil Aviation (Transport Canada), which is the aviation authority for Canada, has issued Transport Canada AD CF-2019-05, dated February 19, 2019 (referred to after this as “the MCAI”), to address the unsafe condition on these products. The MCAI states:

There has been one reported incident on a PT6B-37A engine, where the contamination from galvanic corrosion between the FCU aluminum body and the steel union fitting has caused the loss of engine control, resulting in an engine over-speed condition and subsequently leading to an engine inflight shutdown (IFSD). This condition, if not corrected, could lead to additional cases of IFSDs, which on a single engine helicopter may result in an emergency autorotation landing. To address the subject galvanic corrosion problem in the FCU, P&WC has issued Service Bulletin (SB) 39107 to replace the affected FCUs with a modified FCU that is not susceptible to the subject galvanic corrosion problem. This [Transport Canada] AD mandates compliance with P&WC SB 39107, requiring the replacement of the affected FCUs to mitigate the potential unsafe condition.

You may obtain further information by examining the MCAI in the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2020-0471.

The FAA gave the public the opportunity to participate in developing this final rule. The FAA has considered the comment received. An individual commenter supported the NPRM.

The FAA reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting this final rule as proposed except for minor editorial changes. The FAA has determined that these minor changes:

• Are consistent with the intent that was proposed in the NPRM for addressing the unsafe condition; and

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

The FAA reviewed P&WC Service Bulletin (SB) No. PT6B-72-39107, Revision No. 1, dated December 13, 2017. The SB describes procedures for replacing the FCU. 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 the ADDRESSES section.

The FAA estimates that this AD affects 75 engines installed on helicopters of U.S. registry.

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

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.

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 this AD:

(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.

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:

1. The authority citation for part 39 continues to read as follows:

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