AD/HU 369/102 - Thruster Control Cables (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 369/102 Thruster Control Cables 1/2000

TX

Applicability: Model 500N S/no. 001 to 099 prefixed "LN" and model 600N S/no. 003 to 074 prefixed "RN".

Requirement: 1. Inspect the forward and centre thruster control cables in accordance with:

1. MD Helicopters Inc. Service Bulletin SB 500N-021 or SB 600N-028 for cracking, corrosion or other damage in the cap at the telescopic swivel end; and then

b. MD Helicopters Inc. Service Bulletin SB 500N-020R1 or SB600N-027R1 in the cap relieved area.

2. Install forward and centre thruster control cables P/n 500N7201-55 and -57, in model 500N, or P/n 500N7201-55 and -59 in model 600N.

Note: FAA AD 99-25-08 refers.

Compliance: 1. Within:

1. 5 hours time in service after the effective date of this Directive, and

b. 100 hours time in service after the effective date of this Directive or before 28 February 2000 whichever occurs first.

Thereafter repeat both inspections at intervals not exceeding 100 hours time in service, or 3 months; whichever occurs first, until modified in accordance with 2.

2. Before 01 December 2000.

This Airworthiness Directive becomes effective on 17 December 1999.

Background: This Directive is issued following discovery of stress corrosion cracking in the forward and centre thruster control cable conduit cap at the telescopic swivel end, and in the relieved area. The named thruster cables control the NOTAR directional control thruster and the LH vertical stabiliser. Failure of a cable could cause a fixed thruster condition and loss of normal anti-torque directional control.