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###### Department of Transportation

###### Federal Aviation Administration

          - 14 CFR Part 39
          - [Docket No. FAA-2013-0751; Directorate Identifier 2012-SW-051-AD]
          - RIN 2120-AA64

# AGENCY:

Federal Aviation Administration (FAA), DOT.

# ACTION:

Proposed rule; withdrawal.

# SUMMARY:

The FAA is withdrawing a notice of proposed rulemaking (NPRM) that proposed to supersede Airworthiness Directive (AD) 2011-18-52, which applies to certain Agusta Model AB139 and AW139 helicopters. AD 2011-18-52 requires establishing a revised life limit for each tail rotor blade (blade), updating the existing historical records for your helicopter, repetitively inspecting each blade for a crack, and replacing certain blades. The NPRM was prompted by the manufacturer developing an improved blade using different materials and establishing life limits for those newly-designed blades. The NPRM proposed to require expanding the applicability to include the newly-designed blades and establish their life limits, and proposed to retain the requirement to inspect each blade for a crack and, if there is a crack, replace each blade with an airworthy blade. Since issuance of the NPRM, the FAA has determined that the NPRM does not adequately address the identified unsafe condition. Accordingly, the NPRM is withdrawn.

# DATES:

The FAA is withdrawing the proposed rule published September 5, 2013 (78 FR 54596), as of February 25, 2021.

# ADDRESSES:

## Examining the AD Docket

                    You may examine the AD docket on the internet at                     *https://www.regulations.gov*                     by searching for and locating Docket No. FAA-2013-0751; 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 AD action, the European Aviation Safety Agency (now European Union Aviation Safety Agency (EASA) AD, any comments received, and other information. The street 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:

                        Matt Fuller, AD Program Manager, Operational Safety Branch, Airworthiness Products Section, General Aviation & Rotorcraft Unit, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone 817-222-5110; email                         *matthew.fuller@faa.gov*.                    

# SUPPLEMENTARY INFORMATION:

## Discussion

                    The FAA issued an NPRM to amend 14 CFR part 39 to supersede AD 2011-18-52, Amendment 39-17020 (77 FR 23109, April 18, 2012) (AD 2011-18-52). AD 2011-18-52 applies to Agusta Model AB139 and AW139 helicopters with a blade part number (P/N) 3G6410A00131 or P/N 4G6410A00131 installed. AD 2011-18-52 requires establishing a revised life limit for each blade, updating the existing historical records for your helicopter, repetitively inspecting each blade for a crack, and replacing certain blades. The NPRM published in the                     **Federal Register**                     on September 5, 2013 (78 FR 54596). The NPRM was prompted by the manufacturer first developing two new blades with an improved design and specified life limits and repetitive inspections for the blades. Also, EASA issued AD No. 2012-0030, dated February 17, 2012, which superseded EASA EAD No. 2011-0156-E, dated August 25, 2011, to add the new blades to the required actions. The manufacturer then developed two new blades with improved materials and specified new life limits and inspections for the blades. EASA then issued EASA AD No. 2012-0076, dated May 2, 2012, revised by EASA AD No. 2012-0076R1, dated July 13, 2012 (EASA AD No. 2012-0076R1), to require the repetitive inspections and reduced life limits on the additional new blades.                

## Actions Since the NPRM Was Issued

After issuance of the NPRM, EASA issued EASA AD No. 2012-0076R2, dated February 20, 2014, which revises EASA AD No. 2012-0076R1, to remove the repetitive 25 flight-hour inspections for blades P/N 3G6410A00132, P/N 4G6410A00132, P/N 3G6410A00133, and P/N 4G6410A00133 and extend the life limits for T/R blades P/N 3G6410A00133 and P/N 4G6410A00133. Additionally, EASA advised that the life limits for T/R blades P/N 3G6410A00132 and P/N 4G6410A00132 have been incorporated in the Chapter 4 airworthiness limitations section of the maintenance manual. Further, since the FAA issued the NPRM, a significant amount of time has elapsed, which would require the FAA to reopen the comment period to allow the public an opportunity to comment on the proposed actions. Accordingly, the FAA has determined the NPRM does not adequately address the identified unsafe condition and has determined to withdraw the published NPRM and proceed with a separate rulemaking to address this unsafe condition.

Withdrawal of the NPRM constitutes only such action and does not preclude the FAA from further rulemaking on this issue, nor does it commit the FAA to any course of action in the future.

## Comments

The FAA gave the public the opportunity to comment on the NPRM. The FAA received comments from one commenter.

One commenter requested the FAA adjust the life limit for certain part-numbered blades to be more consistent with aviation standard practices and gave the examples of “3 years since initial installation” and “5 years since manufacture.” Since the FAA is withdrawing the NPRM, the commenter's request to adjust the compliance time is no longer necessary.

## FAA's Conclusions

                    Upon further consideration, the FAA has determined that the NPRM does not adequately address the identified unsafe condition and the unsafe condition will be addressed in a separate AD. Accordingly, the NPRM is withdrawn.                          ( print page 11478)    

## Regulatory Findings

Since this action only withdraws an NPRM, it is neither a proposed nor a final rule. This action therefore is not covered under Executive Order 12866, the Regulatory Flexibility Act, or DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979).

# List of Subjects in 14 CFR Part 39

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

## The Withdrawal

                     Accordingly, the notice of proposed rulemaking, Docket No. FAA-2013-0751, which was published in the                     **Federal Register**                     on September 5, 2013 (78 FR 54596), is withdrawn.                

Issued on January 21, 2021.

Lance T. Gant, 

Director, Compliance & Airworthiness Division, Aircraft Certification Service.

[FR Doc. 2021-03661 Filed 2-24-21; 8:45 am]

BILLING CODE 4910-13-P