Airworthiness Directive · Amendment 39-17519 · Hydraulic pump, main
Eurocopter France (Eurocopter) Helicopters
Superseded. A later AD replaced this one: AD 2017-22-05. Comply with the one in force.
This AD applies to Eurocopter Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, AS350C, AS350D and AS350D1 helicopters with a single hydraulic system and with a hydraulic pump drive installed in accordance with modification 079566 that has 165 or more hours time-in-service (TIS) since installation, certificated in any category.
We are adopting a new airworthiness directive (AD) for Eurocopter Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, AS350C, AS350D, and AS350D1 helicopters with a single hydraulic system and a certain hydraulic pump drive installed. This AD requires inspecting the hydraulic pump drive pulley bearing (pulley bearing) for leaks, rust, overheating, and condition. This AD is prompted by six reports of hydraulic pump drive belt failure caused by seizure of the pulley bearing. These actions are intended to prevent hydraulic pump drive belt failure, loss of hydraulic servo assistance, and subsequent loss of control of the helicopter.
You are responsible for performing each action required by this AD within the specified compliance time.
Within 10 hours TIS, and thereafter at intervals not exceeding 25 hours TIS:
(1) Uncouple the pulley from the hydraulic pump.
(2) Using a mirror and a light, inspect the hydraulic pump drive pulley bearing (pulley bearing) for leaking grease from each lip seal of the four greasing orifices (lip seal) due to wear, a crack or tear in a lip seal, a run of rust on a lip seal, indication of overheating shown by brown coloring on the inner ring of the bearing, and for any distortion, impact, wear, a tear, a crack, or loss of grease on each sealing flange.
(3) Manually rotate the pulley bearing through several full turns and inspect for a friction point, brinelling, or a noise from the bearing.
(4) If there is any leaking grease from a lip seal, a crack or tear in a lip seal, a run of rust on a lip seal, indication of overheating shown by brown coloring on the inner ring of the bearing, or distortion, impact, wear, a tear, a crack, or loss of grease on a sealing flange, or a friction point, brinelling, or noise from the bearing, before further flight, replace the hydraulic pump drive assembly.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
