Airworthiness Directive · Amendment 39-12049 · Eurocopter Deutschland Model EC135 P1 and T1 Helicopters
Eurocopter Deutschland Model EC135 P1 and T1 Helicopters
Model EC135 P1 and T1 helicopters, with tail boom serial number EVL 001 through EVL 045, installed, certificated in any category.
Note 1: This AD applies to each helicopter identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For helicopters that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (b) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.
This amendment supersedes an existing airworthiness directive (AD) that applies to Eurocopter Deutschland Model EC135 P1 and T1 helicopters. That AD currently requires visual and dye-penetrant inspections for a cracked stator blade of the fenestron tail rotor (tail rotor). That AD also requires either stop drilling a cracked blade or, as necessary, replacing an unairworthy stator blade with an airworthy stator blade. This amendment requires replacing the existing stator blade assembly with a new stator blade assembly that incorporates a reinforced base and modified riveting and limits the applicability to certain serial numbered tail booms. This amendment is prompted by additional reports of cracked stator blades of the tail rotor. The actions specified by this AD are intended to prevent failure of the tail rotor and subsequent loss of control of the helicopter.
To prevent failure of the stator blades of the fenestron tail rotor and subsequent loss of control of the helicopter, accomplish the following:
(a) Replace stator blade assembly, part number (P/N) L 535A4201 052, with stator blade assembly, P/N L 535A4201 053.
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.
