AD/DHC-8/33 - Electronic Engine Control Cable Harness Lightning Protection (Cth)

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

Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes

AD/DHC-8/33 Electronic Engine Control Cable Harness Lightning Protection

8/94 DM

Applicability: Models 102, 103 and 106, serial numbers 3 to 369 inclusive, and Models 301, 311 and 314, serial numbers 100 to 370 inclusive.

Requirement: Action in accordance with Bombardier Regional Aircraft Division de Havilland Dash 8 Service Bulletin S.B. 8-73-18 dated 29 April 1994 or SB 8-73-19 dated 29 April 1994 as applicable.

Note: Transport Canada AD CF-94-09 dated 6 May 1994 refers.

Compliance: Prior to 28 August 1994.

Background: AD/DHC-8/7 Amdt 1 required the incorporation of five modifications designed to minimise the danger of lightning transient-induced damage to the electronic engine control units. Transport Canada have advised, that despite the required modifications being incorporated a DHC-8 aircraft experienced an engine flameout following a lightning strike, subsequent investigation revealed several engine control cable harness shields were not grounded in accordance with the modifications. This Directive requires a one time inspection to verify the integrity of the engine control cable harness shield grounds and, if necessary, the rework of any grounds that do not satisfy the resistance measurement specifications.