This PDF is the current document as it appeared on Public Inspection on 11/23/2016 at 08:45 am.
Federal Aviation Administration (FAA), DOT.
Proposed rule; withdrawal.
The FAA is withdrawing a notice of proposed rulemaking (NPRM). The NPRM proposed to supersede airworthiness directive (AD) 2007-25-08 for Eurocopter France (now Airbus Helicopters) Model SA-365N1, AS-365N2, AS 365 N3, SA-366G1, EC 155B, and EC155B1 helicopters. The proposed actions were intended to prevent damage to the tail gearbox (TGB) control shaft and rod assembly bearing resulting in end play, loss of tail rotor pitch control, and subsequent loss of control of the helicopter. Since we issued the NPRM, we have received reports of new occurrences of loss of yaw control due to failure of the control rod bearing and determined that different actions at shorter time intervals are necessary to correct the unsafe condition. Accordingly, we withdraw the proposed rule.
DATES:Start Further Info
FOR FURTHER INFORMATION CONTACT:
David Hatfield, Aviation Safety Engineer, Safety Management Group, Rotorcraft Directorate, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone (817) 222-5116; email firstname.lastname@example.org.End Further Info End Preamble Start Supplemental Information
On August 21, 2015, the FAA issued an NPRM that proposed to amend 14 CFR part 39 to remove AD 2007-25-08 (72 FR 69604, December 10, 2007) and add a new AD for Airbus Helicopters (previously Eurocopter France) Model SA 365N1, AS-365N2, AS 365 N3, SA-366G1, EC 155B, and EC155B1 helicopters. The NPRM published in the Federal Register on September 2, 2015 (80 FR 53024). The NPRM proposed to require, at specified intervals, checking the TGB oil level and inspecting the TGB magnetic plug for chips at specified intervals. The NPRM also proposed replacing the TGB guide bushes, inspecting the bearing of the TGB control shaft and rod assembly for M50 type particles, and performing measurements of play in the TGB control shaft and rod assembly. Finally, after replacing the guide bush, the NPRM proposed repetitively performing measurements for play in the TGB control shaft and rod assembly. The NPRM did not apply to helicopters with TGB part number (P/N) 365A33-6005-09 installed, which Airbus Helicopters refers to as Modification 07 65B63. At the time the NPRM was published, we had received new reports of loss of yaw control due to failure of the control rod bearing. The proposed actions were intended to prevent damage to the bearing resulting in end play, loss of tail rotor pitch control, and subsequent loss of control of the helicopter.
Actions Since the NPRM Was Issued
Since we issued the NPRM (80 FR 53024, September 2, 2015), EASA issued Emergency AD No. 2016-0097-E, dated May 23, 2016, which was subsequently revised by AD No. 2016-0097R1, dated May 25, 2016, to correct a paragraph reference. EASA AD No. 2016-0097R1 advises that a technical investigation of an AS 365 N3 accident revealed a damaged TGB bearing. EASA further states that the affected control rod had been repetitively inspected as required by a previous AD, EASA AD No. 2012-0170R2, dated June 20, 2014, and that the investigation is still ongoing to determine the root cause of the damage and why the damage was not discovered during the inspections. EASA AD No. 2016-0097R1 requires repetitive inspections of the TGB oil level and magnetic chip detector. EASA AD No. 2016-0097R1 also requires replacing bearing P/N 704A33-651-093 or P/N 704A33-651-104 with an improved bearing P/N 704A33-651-245 or 704A33-651-246, which is terminating action for the repetitive inspections of the magnetic chip detector but not of the oil level. The EASA AD also describes an alternative repetitive inspection for play that would defer replacing the bearing for an additional 110 hours time-in-service.
In light of this latest information, we are issuing a separate action to supersede AD 2007-25-08 (72 FR 69604, December 10, 2007) with immediately effective requirements. Accordingly, we are withdrawing the NPRM.
After our NPRM (80 FR 53024, September 2, 2015) was published, we received two comments from one commenter.
Airbus Helicopters requested that the applicability be changed to exclude helicopters with MOD 07 65B63 (which installs TGB P/N 365A33 6005-09) instead of those with TGB P/N 365A33 6005-09. When asked for additional information to support this comment, Airbus Helicopters stated that by excluding only helicopters with TGB P/N 365A33 6005-09, the NPRM would apply to helicopters with a new (future) TGB P/N that would not be subject to the unsafe condition. If instead the NPRM were to exclude helicopters with MOD 07 65B63, it would also exclude future TGB P/Ns. MOD 07 65B63 would be required before any future MOD that may install a new part-numbered TGB.
We agree with the commenter's concern. However, because we are withdrawing the NPRM and issuing a separate action with different corrective requirements, the commenter's request is no longer necessary.
Airbus Helicopters also requested that the compliance intervals for performing the measurements for play include the longer interval allowed for helicopters with MOD 07 65B57.
We agree that the longer inspection intervals are acceptable for helicopters with MOD 07 65B57. However, because we are withdrawing the NPRM and issuing a separate action with different corrective requirements, the commenter's request is no longer necessary.
Withdrawal of the NPRM constitutes only such action and does not preclude the agency from issuing another notice in the future nor does it commit the agency to any course of action in the future.
Since this action only withdraws an NPRM, it is neither a proposed nor a final rule; therefore, it is not covered under Executive Order 12866, the Regulatory Flexibility Act, or DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979).Start List of Subjects
List of Subjects in 14 CFR Part 39
- Air transportation
- Aviation safety
- Incorporation by reference
Accordingly, the notice of proposed rulemaking, Docket No. FAA-2015-3657; Directorate Identifier 2012-SW-069-AD, published in the Federal Register on September 2, 2015 (80 FR 53024), is withdrawn.Start Signature
Issued in Fort Worth, Texas, on November 2, 2016.
Lance T. Gant,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2016-27639 Filed 11-23-16; 8:45 am]
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