Airworthiness Directive · Amendment 39-17862 · Tail rotor drive bearing
Bell Helicopter Textron, Inc. (Bell) Helicopters
This AD applies to Bell Model 214B helicopters, serial number (S/N) 28001 through 28070, Model 214B-1 helicopters, S/N 28001 through 28070, and Model 214ST helicopters, S/N 28101 through 28200, with a tail rotor hanger bearing (bearing), part number (P/N) 214-040-606-005 or 214-040-606-101 installed, certificated in any category.
We are superseding Airworthiness Directive (AD) 2013-11-05 for Bell Model 214B, 214B-1, and 214ST helicopters with certain tail rotor hanger bearings (bearing) installed. AD 2013-11-05 required inspecting the bearing to determine whether an incorrectly manufactured seal material is installed on the bearing. This new AD retains the repetitive inspection of the bearings and also requires replacing the defective bearings. This AD was prompted by a report that certain bearings were manufactured with an incorrect seal material that does not meet Bell specifications. We are issuing this AD to prevent failure of the bearing 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 10 hours time in service (TIS):
(i) Inspect each bearing to determine whether the seal material is correct, as described in the Accomplishment Instructions, Part 1—Inspection, paragraphs 1.a. through 2. and Figure 1 of Bell Alert Service Bulletin (ASB) No. 214-13-74, Revision A, dated March 25, 2013, for Model 214B and 214B-1 helicopters and ASB No. 214ST-13-90, Revision A, dated March 25, 2013, for Model 214ST helicopters.
(ii) For each bearing with black seal material, before further flight and thereafter at intervals not to exceed 10 hours TIS, inspect the bearing for leakage, slung grease, or damage. If there is any leakage, slung grease, or damage, before further flight, replace the bearing with an airworthy bearing with red/orange to brown color seal material.
(2) Within 500 hours TIS or 6 months, whichever occurs earlier, replace any bearing with black seal material with an airworthy bearing with red/orange to brown color seal material.
(3) Do not install bearing P/N 214-040-606-005 or 214-040-606-101 with black seal material 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.
