AD 2022-10-06

This AD is effective June 28, 2022.

For service information identified in this final rule, contact Rolls-Royce Corporation, 450 South Meridian Street, Mail Code NB-01-06, Indianapolis, IN 46225; phone: (317) 230-2720; email: HelicoptCustSupp@Rolls-Royce.com; website: www.rolls-royce.com. You may view this service information at the Airworthiness Products Section, Operational Safety Branch, FAA, 1200 District Avenue, Burlington, MA 01803. For information on the availability of this material at the FAA, call (817) 222-5110.

John Tallarovic, Aviation Safety Engineer, Chicago ACO, FAA, 2300 E Devon Avenue, Des Plaines, IL 60018; phone: (847) 294-8180; email: john.m.tallarovic@faa.gov.

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2017-18-14, Amendment 39-19023 (82 FR 42443, September 8, 2017), (AD 2017-18-14). AD 2017-18-14 applied to certain RRC 250-C20, -C20B, -C20F, -C20J, -C20R, -C20R/1, -C20R/2, -C20R/4, -C20W, -C300/A1, and -C300/B1 turboshaft engines with either a 3rd-stage turbine wheel, part number (P/N) 23065818, or a 4th-stage turbine wheel, P/N 23055944 or RR30000240, installed. The NPRM published in the Federal Register on January 14, 2022 (87 FR 2365). The NPRM was prompted by in-service turbine blade failures that resulted in the loss of power and engine in-flight shutdowns. Since the FAA issued AD 2017-18-14, the manufacturer redesigned the 3rd-stage turbine wheel. The manufacturer published Rolls-Royce Alert Commercial Engine Bulletin (CEB) CEB A-1428/CEB A-72-4111 (single document), which describes procedures for replacement of the 3rd-stage turbine wheel, P/N 23065818, with the new increased blade fillet 3rd-stage turbine wheel, P/N M250-10473. Additionally, the FAA determined that the RRC 250-C20C (T63-A-720) model turboshaft engine is also susceptible to the unsafe condition. In the NPRM, the FAA proposed to require replacement of the 3rd-stage and 4th-stage turbine wheels. The FAA is issuing this AD to address the unsafe condition on these products.

The FAA received comments from two commenters. The commenters were an anonymous commenter and RRC. The following presents the comments received on the NPRM and the FAA's response to each comment.

The anonymous commenter stated that RRC does not have the inventory to supply engine shops with the 3rd-stage and 4th-stage turbine wheels proposed for replacement in the NPRM. The commenter requested that RRC provide credit to its customers for unused time on 3rd-stage and 4th-stage turbine wheels and reasoned that customers paid for the full life of the 3rd-stage and 4th-stage turbine wheels, not a partial life, which now requires replacement at full price. The commenter also stated that the part cost estimates in the NPRM for the 3rd-stage and 4th-stage turbine wheels are inaccurate and should indicate an estimated cost of $22,929.15 and $18,926.59 to reflect Aviall and Boeing's prices, respectively. The commenter noted that they have found performing FPIs on the 3rd-stage and 4th-stage turbine wheels result in serviceable conditions compared to the previous configurations that were beyond serviceable. The commenter expressed that the proposed requirements in the NPRM would be a financial burden on RRC's customers, considering the current market instability.

The FAA disagrees that the manufacturer will not have sufficient inventory, which would prevent compliance with this AD. Prior to publishing the NPRM, the FAA confirmed with RRC that there would be adequate inventory for operators to replace the 3rd-stage and 4th-stage turbine wheels. In response to this comment, the FAA confirmed with RRC that the 3rd-stage and 4th-stage turbine wheels are available at a 50% discounted price. Additionally, RRC indicated that suppliers will also provide the discounted price. The FPI of 3rd-stage turbine wheels was an interim action until redesigned parts became available. While FPI reduces the risk of a blade failure, the unsafe condition is addressed by replacing the 3rd-stage turbine wheel with the revised design. The FAA did not change this AD as a result of the comments.

RRC requested that the FAA revise the Related Service Information paragraph of this AD to reference Rolls-Royce Alert CEB CEB A-1428/CEB A-72-4111 (single document), Revision 2, dated December 8, 2021. RRC reasoned that since the three Rolls-Royce bulletins were submitted to the FAA in support of the NPRM, Rolls-Royce has published Revision 2 of Rolls-Royce Alert CEB CEB A-1428/CEB A-72-4111 (single document).

The FAA agrees. The FAA has updated the Related Service Information paragraph of this AD to reference Rolls-Royce Alert CEB CEB A-1428/CEB A-72-4111 (single document), Revision 2, dated December 8, 2021.

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

The FAA reviewed Rolls-Royce Alert CEB CEB A-1428/CEB A-72-4111 (single document), Revision 2, dated December 8, 2021. This Alert CEB describes procedures for replacing the 3rd-stage turbine wheel, P/N 23065818, with the new increased blade fillet 3rd-stage turbine wheel, P/N M250-10473.

The FAA reviewed Rolls-Royce Alert CEB CEB-A-1422/CEB-A-72-4108 (single document), Original Issue, dated September 13, 2017. This Alert CEB describes procedures for replacing 4th-stage turbine wheel, P/N 23055944, with the new increased blade fillet 4th-stage turbine wheel, P/N M250-10445.

The FAA also reviewed Rolls-Royce Alert Service Bulletin (SB) RR300-A-72-024, Original Issue, dated September 13, 2017. This Alert SB describes procedures for replacing the 4th-stage turbine wheel, P/N RR30000240, with the new increased blade fillet 4th-stage turbine wheel, P/N RR30000494.

The FAA estimates that this AD affects 3,769 engines installed on helicopters of U.S. registry. The FAA estimates that 3,041 3rd-stage turbine wheels and 3,769 4th-stage turbine wheels will require replacement.

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

The FAA has included all known costs in its cost estimate. According to the manufacturer, however, some of the costs of this AD may be covered under warranty, thereby reducing the cost impact on affected operators.

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.

The FAA has determined that 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.

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:

a. Removing Airworthiness Directive 2017-18-14, Amendment 39-19023 (82 FR 42443, September 8, 2017); and

b. Adding the following new airworthiness directive: