AD/BELL 206/146 - Engine RPM Sensor - Limitations (Cth)

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES

Bell Helicopter Textron Canada (BHTC) 206 and Agusta Bell 206 Series Helicopters

AIRWORTHINESS DIRECTIVE

For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

AD/BELL 206/146 Engine RPM Sensor - Limitations 7/2001 DM

Applicability: All Model 206B and Series 206L helicopters equipped with Allison 250-C20R engine and Soloy engine power-out warning sensors, part number 206-075-545-001, in accordance with Supplemental Type Certificate (STC) SH 95-46 (FAA STC SH4179NM, applicable to Model 206B) and SH 95-45 (FAA STC SH4169NM, applicable to Model 206L).

Note 1: This Directive is not applicable to helicopters with a part number (P/N) 680- 2551-1 engine out sensor.

Requirement: If not previously accomplished, revise the Limitations Section of the applicable approved STC Rotorcraft Flight Manual Supplement by adding the following Warning Statement and Note:

WARNING: For aircraft with an engine-out sensor other than P/N 680- 2551-1 only. To prevent false engine-out signals, the following procedure must be followed during practice auto-rotations. When entering a practice auto-rotation, avoid a pausing or creeping movement of any throttle decrease or increase between full open and idle. If movement is not made at a firm and continuous rate, N1 RPM undershoot and/or oscillation may occur causing a momentary false engine-out warning light and audio indication.