Airworthiness Directive · Amendment 39-17404 · Eurocopter France Helicopters
Eurocopter France Helicopters
This AD applies to Model SA-365N1, AS-365N2, and AS 365 N3 helicopters, with the GV76-1 vertical gyro unit installed on the left-hand (LH) or right-hand (RH) shelf in the rear cargo compartment, pre-MOD 365P081895, certificated in any category, all serial numbers except 6698, 6701, 6723, 6737, and 6741.
We are adopting a new airworthiness directive (AD) for Eurocopter France (Eurocopter) Model SA-365N1, AS-365N2, and AS 365 N3 helicopters. This AD requires revising the Limitations section of the Rotorcraft Flight Manual (RFM) to prohibit flight in instrument meteorological conditions (IMC) or night visual flight rules (VFR) for each helicopter with a vertical gyro unit GV76-1 installed upon a non- reinforced shelf in the rear cargo compartment. Also, this AD requires modifying the GV76-1 vertical gyro unit shelf and testing for correct function of the navigation systems. This AD was prompted by flight crew reports of deviations between the displayed attitude on the attitude display screen and the independent electromechanical standby attitude indicator. The actions of this AD are intended to prevent an undetected flight display error of a slow drift in the roll axis, disorientation of the pilot, and subsequent loss of control of the helicopter.
You are responsible for performing each action required by this AD within the specified compliance time unless it has already been accomplished prior to that time.
(1) Before further flight, revise the Limitations section of the Rotorcraft Flight Manual (RFM) by inserting a copy of this AD into the RFM or by pen and ink changes to the RFM that prohibits flight in instrument meteorological conditions (IMC) or night visual flight rules (VFR) for each helicopter with a vertical gyro unit GV76-1 installed on the rear cargo compartment shelf without reinforcement per Modification 365P081895.
(2) Within 110 hours time-in-service, modify the GV76-1 vertical gyro unit shelf as depicted in Figures 1 through 3 and by following the Accomplishment Instructions, paragraphs 2.A. through 2.B.2.e., of Eurocopter Alert Service Bulletin No. 34.00.31, Revision 1, dated July 28, 2010. After reinforcing the shelf, operationally test the GV76-1 vertical gyro unit and functionally test the navigation systems.
(3) After modifying the GV76-1 vertical gyro unit shelf, remove this AD from the Limitations section of the RFM or remove any changes to the Limitations section of the RFM that prohibit flight in IMC or VFR as a result of paragraph (e)(1) of this AD.
(4) Modifying the GV76-1 vertical gyro unit shelf is terminating action for the requirements of this AD.
