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[Federal Register Volume 81, Number 227 (Friday, November 25, 2016)]
[Proposed Rules]
[Pages 85168-85169]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-27639]

[[Page 85168]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2015-3657; Directorate Identifier 2012-SW-069-AD]
RIN 2120-AA64

Airworthiness Directives; Airbus Helicopters (Previously 
Eurocopter France) Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Proposed rule; withdrawal.

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SUMMARY: 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: As of November 25, 2016, the proposed rule to amend 14 CFR part 
39 published September 2, 2015 (80 FR 53024) is withdrawn.

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 
david.hatfield@faa.gov.

SUPPLEMENTARY 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.

Comments

    After our NPRM (80 FR 53024, September 2, 2015) was published, we 
received two comments from one commenter.

Request

    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).

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-
2015-3657; Directorate Identifier 2012-SW-069-AD, published in the 
Federal Register on September 2, 2015 (80 FR 53024), is withdrawn.

[[Page 85169]]

    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]
 BILLING CODE 4910-13-P
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