Applicability: Model BK 117, BK117A-3, BK117A-4, BK117B-1, BK117B-2, and BK117C-1 helicopters; all main rotor blade part numbers.

Requirement:

1. Revise the KHI-BK117 Maintenance Manual to Revision No. 14 (or later approved revision) for Models KHI-BK 117, BK117A-3, BK117A-4, BK117B-1, BK117B-2, and Revision No. 2 (or later approved revision) for Model KHIBK117C-1.

2. Perform the inspection in accordance with the inspection interval and method specified in the KHI-BK117 Maintenance Manual, revised by Requirement 1. If the inspection results exceed the allowable limit specified in the KHI-BK117 Maintenance Manual, before further flight, contact KHI Customer Service for technical advice.

Note 1: Kawasaki Service Bulletin No. KSB-117-115A refers.

Note 2: JCAB AD TCD-4114A-2006 refers.

Compliance: Initially, before further flight after 28 March 2006. Thereafter as specified in Requirement 2. This Amendment becomes effective on 28 March 2006.

Background: In response to incidents, the manufacturer recommended an immediate inspection for bulging on the upper and lower surfaces of the main rotor blades in the area of the outboard lead balance weight. Amendment 1 referenced the JCAB AD and the Kawasaki service bulletin rather than the LBA AD and the MBB service bulletin of the initial issue. Amendment 2 introduced an additional blade part number to applicability. Amendment 3 is issued in response to a new JCAB AD, which expands applicability to all main rotor blade part numbers. Amendment 4 is issued in response to a new JCAB AD, which transfers the inspection requirements of this Directive to the KHI-BK117 Maintenance Manual. This also introduces an additional inspection. The original issue of this Airworthiness Directive became effective on 13 October 1994.

FMI: www.casa.gov.au