FAA orders · airworthiness directive · current

2008-08-16: Digital electronic control units (DECUs)

FAA order 2008-08-16 is an airworthiness directive in force since May 21, 2008. The FAA's subject line: Digital electronic control units (DECUs). It names the Turbomeca (Safran) MAKILA 1A1 engine: about 8 aircraft on the U.S. register today, though an order usually covers particular versions or serial numbers rather than every one. System: engine.

What it applies to as the FAA lists it

Kind of product: Engine
Makes: Turbomeca S.A.
Models: Makila 1A, Makila 1A1
Engine series: Turbomeca (Safran) MAKILA 1A1 8 aircraft

Dates and paperwork

In force since: May 21, 2008
Published: April 16, 2008 (signed April 8, 2008)
Docket: FAA-2007-0157
Replaces: 2002-15-05
Status: Current
The FAA's document: Read the order on the FAA's site

The FAA's summary their words, unchanged

The FAA is superseding an existing airworthiness directive (AD) for Turbomeca Makila 1A, 1A1, and 1A2 turboshaft engines. That AD currently requires replacing certain digital electronic control units (DECUs) and electronic control units (ECUs) with modified DECUs and ECUs. This AD applies only to Makila 1A and 1A1 turboshaft engines, and requires replacing the selector-comparator board in the ECU with a board incorporating Turbomeca modification TU 250. This AD results from recent unexplained reversions of the ECU to the 65% N1 back-up mode. We are issuing this AD to prevent dual-engine continued operation at 65% N1 after reversion of the ECU to the 65% N1 back-up mode due to temporary loss of N2 speed signal, which could lead to inability to continue safe flight, emergency autorotation landing, or an accident.

The order itself the regulatory text, as published

Show the full text (1,961 characters)

2008-08-16 Turbomeca: Amendment 39-15469. Docket No. FAA-2007-0157; Directorate Identifier 2001-NE-23-AD. 

Effective Date 

	(a) This airworthiness directive (AD) becomes effective May 21, 2008. 

Affected ADs 

	(b) This AD supersedes AD 2002-15-05, Amendment 39-12833. 

Applicability 

	(c) This AD applies to Turbomeca Makila 1A and 1A1 turboshaft engines. These engines are installed on, but not limited to, Eurocopter France model AS 332C, AS 332L, and AS 332L1 helicopters. 

Unsafe Condition 

	(d) This AD results from recent unexplained reversions of the electronic control unit (ECU) to the 65% N1 back-up mode. The actions specified in this AD are intended to prevent dual-engine continued operation at 65% N1 after reversion of the ECU to the 65% N1 back-up mode due to temporary loss of N2 speed signal, which could lead to inability to continue safe flight, emergency autorotation landing, or an accident. 

Compliance 

	(e) You are responsible for having the actions required by this AD performed before June 30, 2008, unless the actions have already been done. 
	(f) Replace the selector-comparator board in the ECU with a board incorporating Turbomeca Modification TU 250. Information on Modification TU 250 can be found in Turbomeca Mandatory Service Bulletin No. 298 73 0250, dated March 23, 2007. 

Alternative Methods of Compliance 

	(g) The Manager, Engine Certification Office, FAA, has the authority to approve alternative methods of compliance for this AD if requested using the procedures found in 14 CFR 39.19. 

Related Information 

	(h) European Aviation Safety Agency AD 2007-0144, dated May 18, 2007, also addresses the subject of this AD. 
	(i) Contact James Lawrence, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: james.lawrence@faa.gov; telephone (781) 238-7176; fax (781) 238- 7199, for more information about this AD.

Source: FAA Dynamic Regulatory System, airworthiness directives. The FAA's document is the authority; the register counts are this site's, from the FAA register of October 12, 2026. Connections as data: /graph/directive/2008-08-16.json · aircraft systems.