AIRWORTHINESS DIRECTIVE
On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/GBK 117/6 Amdt 3 and issues the following AD under subregulation 39.001(1) of CASR 1998.  The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.
Eurocopter BK 117 Series Helicopters
AD/GBK 117/6 Amdt 4
Main Rotor Blade
11/2007
 
Applicability:
Models BK117A-1, A-3, A-4, B-1, B-2, and C-1, all Main Rotor Blade part numbers except P/N 117-151511 and P/N 117-151521.

Requirement:
1.    Incorporate Revision No. 24 (for MBB-BK117 A-1 through B-2) and Revision No. 5 (for MBB-BK117 C-1) into the Eurocopter Deutschland MBB-BK117 Maintenance Manual.
2.    Inspect the upper and lower surfaces of the main rotor blades for bulging in the area of the outboard lead balance weight in accordance with the applicable
MBB-BK117 Maintenance Manual.
3.    If the inspection results are outside the allowable limits specified in the
MBB-BK117 Maintenance Manual, ECD Customer Service must be consulted for advice on serviceability.
Note:  LBA AD D-1994-280R3 refers.

Compliance:
1.    Before 31 December 2005, unless already accomplished.
2.    As specified in the applicable MBB-BK117 Maintenance Manual.
3.    Before further flight.

 
This Amendment becomes effective on 25 October 2007.

Background:
In response to recent incidents, the manufacturer recommends 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 included all main rotor blades.
Amendment 2 reflected the changed issue date of the LBA AD, no further work was required.
Amendment 3 was issued in response to a revision of the related LBA AD.  The amendment corrected applicability and specified the requirements of the latest LBA AD.

 
 
Amendment 4 is issued to exclude certain Main Rotor Blade part numbers from inspection in accordance with this Airworthiness Directive.  There is no change to the requirements or compliance.

David Villiers
Delegate of the Civil Aviation Safety Authority
7 September 2007