Airworthiness Directive · Amendment 39-21448 · Tail rotor
Airbus Helicopters
Superseded. A later AD replaced this one: AD 2022-09-04. Comply with the one in force.
This AD applies to Airbus Helicopters Model SA-365N1, AS-365N2, AS 365 N3, SA-366G1, EC 155B, and EC155B1 helicopters, certificated in any category, all serial numbers.
The FAA is superseding Airworthiness Directive (AD) 2016-23- 05, which applied to certain Airbus Helicopters Model SA-365N1, AS- 365N2, AS 365 N3, SA-366G1, EC 155B, and EC155B1 helicopters. AD 2016- 23-05 required repetitive checks of the oil level of the tail rotor gearbox and, if necessary, filling the oil to the maximum level; and replacement of a certain control rod double bearing (bearing) with a new bearing. This AD retains the requirements of AD 2016-23-05 and also requires modifying the helicopter by replacing the tail gearbox (TGB) control shaft guide bushes; repetitive inspections of the TGB magnetic plug and corrective actions if necessary; repetitive replacements of the bearing; and modifying the helicopter by replacing the TGB; as specified in a European Aviation Safety Agency (now European Union Aviation Safety Agency) (EASA) AD, which is incorporated by reference. This AD also adds helicopters to the applicability. This AD was prompted by reports of occurrences of loss of yaw control due to failure of the TGB bearing. The FAA is issuing this AD to address the unsafe condition on these products.
Except as specified in paragraph (h) of this AD: Comply with all required actions and compliance times specified in, and in accordance with, European Aviation Safety Agency (now European Union Aviation Safety Agency) (EASA) AD 2017-0125, dated July 21, 2017 (EASA AD 2017-0125).
(1) Where EASA AD 2017-0125 refers to its effective date, this AD requires using the effective date of this AD.
(2) Where EASA AD 2017-0125 refers to June 4, 2011 (the effective date of EASA AD 2011-0105), this AD requires using the effective date of this AD.
(3) Where EASA AD 2017-0125 refers to May 25, 2016 (the effective date of EASA AD 2016-0197R1), this AD requires using the effective date of this AD.
(4) The “Remarks” section of EASA AD 2017-0125 does not apply to this AD.
(5) Where paragraph (2) of EASA AD 2017-0125 requires inspections (checks) to be done “in accordance with the instructions of Paragraph 3.B.1 of the applicable inspection ASB,” for this AD, those instructions are for reference only and are not required for the actions in paragraph (2) of EASA AD 2017-0125. The inspections (checks) required by paragraph (2) of EASA AD 2017-0125 may be performed by the owner/operator (pilot) holding at least a private pilot certificate and must be entered into the aircraft records showing compliance with this AD in accordance with 14 CFR 43.9 (a)(1) through (4) and 14 CFR 91.417(a)(2)(v). The record must be maintained as required by 14 CFR 91.417, 121.380, or 135.439.
(6) Where paragraph (5) of EASA AD 2017-0125 specifies to “accomplish the applicable corrective action(s) in accordance with the instructions of Paragraph 3.B.1 of the applicable inspection ASB,” for this AD, a qualified mechanic must add oil to the TGB to the “max” level if the oil level is not at maximum. The instructions are for reference only and are not required for the actions in paragraph (5) of EASA AD 2017-0125.
(7) Where EASA AD 2017-0125 refers to flight hours (FH), this AD requires using hours time-in-service.
(8) Where EASA AD 2017-0125 requires action after the last flight of the day or “ALF,” this AD requires those actions before the first flight of the day.
(9) Where the service information referred to in EASA AD 2017-0125 specifies to perform a metallurgical analysis and contact the manufacturer if collected particles are not clearly characterized, this AD does not require contacting the manufacturer to determine the characterization of the particles collected.
(10) Although service information referenced in EASA AD 2017-0125 specifies to scrap parts, this AD does not include that requirement.
(11) Although service information referenced in EASA AD 2017-0125 specifies reporting information to Airbus Helicopters and filling in a “particle detection” follow-up sheet, this AD does not include those requirements.
(12) Although service information referenced in EASA AD 2017-0125 specifies returning certain parts to an approved workshop, this AD does not include that requirement.
(13) Where paragraph (6) of EASA AD 2017-0125 refers to “any discrepancy,” for this AD, discrepancies include the presence of particles and other conditions such as abrasions, scales, flakes, and splinters.
