AD/HU 369/96 Amdt 1 - Engine Control and Warning Systems (Cth)

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

McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters

AD/HU 369/96 Amdt 1

Engine Control and Warning Systems 6/99 DM

Applicability: Model 369E (serial numbers (S/N) 384E and subsequent), Model 369FF (S/N 076FF and subsequent), Model 500N and Model 600N series helicopters.

Requirement: 1. If not previously accomplished, carry out the following:

(a) Access relays K1, K2, K3, K5, K104, and K200 (relay part number (P/N) HS4240).

(b) Remove each relay specified in sub-paragraph (a) from its receptacle (P/N HS4256-1).

(c) Using a No. 60 drill bit or a 0.40 inch diameter wire as a gauge, attempt to insert the gauge into every contact socket of each relay receptacle, see Figure 1. (To prevent damage to the receptacle and contact socket, ensure the gauge is inserted perpendicular to the face of the receptacle.) If the gauge can be inserted into the contact socket, the socket must be replaced with a new socket P/N 019-0075-002.

2. Inspect any replacement relay, P/N HS4240, in accordance with paragraph (c) of this Directive.

Note 1: FAA Priority Letter AD 99-08-07 refers. COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES

Note 2: Boeing McDonnell Douglas Helicopter Systems (MDHS) Service Bulletin SB369E-090, SB369F-077, SB500N-017, SB600N-014 dated 6 July 1998 pertains to this directive.

Compliance: 1. Prior to 17 May 1999.

2. Prior to fitting to an aircraft.

This Amendment becomes effective on 12 May 1999.

Background: The FAA has received a report of an incident involving a MDHS 600N helicopter where the engine control unit (ECU) fail light illuminated, even though the ECU continued to automatically control the engine. The helicopter manufacturer has also reported two additional similar incidents on other model 600N helicopters. The cause of the ECU malfunction indication was determined to be contact sockets of a relay receptacle that did not correctly fit the corresponding pins of a relay. This directive requires the inspection of the contact sockets of each affected relay receptacle to ensure that the sockets are the correct size.