AD NUMBER: 2010-09-13

MANUFACTURER: Turbomeca Makila 2A Turboshaft Engines
SUBJECT: Airworthiness Directive 2010-09-13

SUMMARY: This AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:

Some digital engine control units (DECUs) used to control MAKILA 2A and MAKILA 2A1 engines have an ambient pressure (P0) sensor with a measurement accuracy that may be outside the range required for satisfactory functioning of the engines throughout the entire operating envelope. In certain extreme flight conditions, the lack of P0 measurement accuracy could potentially cause an engine flameout if the engine is operating on a replacement fuel. The issue is limited to a batch of 24 DECUs, of which 23 are known to be still in service. Since 01 January 2010, any such DECU returned to an approved repair centre has had its P0 sensor checked and replaced as necessary.

We are issuing this AD to prevent an uncommanded engine in-flight shutdown which could result in a forced autorotation landing or accident.

FMI: http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAD.nsf/0/80934A4DD3373C62862577150049E9AA?OpenDocument