Airworthiness Directive · Amendment 39-18667 · Engine and transmission lubrication system
Bell Helicopter Textron Canada Limited (Bell) Helicopters
This AD applies to Bell Model 427 and 429 helicopters, certificated in any category, with an engine and transmission oil check valve part number (P/N) 209-062-520-001 manufactured by Circor Aerospace, marked “Circle Seal” and with a manufacturing date code of “10/11” (October 2011) through “03/15” (March 2015), installed.
We are adopting a new airworthiness directive (AD) for Bell Model 427 and Model 429 helicopters. This AD requires replacing certain engine and transmission oil check valves. This AD also prohibits installing the affected check valves on any helicopter. This AD is prompted by a report of several cracked or leaking check valves. These actions are intended to detect and prevent a cracked or leaking check valve which could result in loss of lubrication to the engine or transmission, failure of the engine or transmission, 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) Within 25 hours time-in-service:
(i) Replace each transmission oil check valve.
(ii) For Model 429 helicopters, replace each engine oil check valve.
(2) After the effective date of this AD, do not install any check valve P/N 209-062-520-001 manufactured by Circor Aerospace, marked “Circle Seal” and with a manufacturing date code of “10/11” (October 2011) through “03/15” (March 2015), on any helicopter.
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.
