AD/PR/37 Propeller Blades Metallic Leading Edge Guard (Cth)

AIRWORTHINESS DIRECTIVE

For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (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.

Propellers - Variable Pitch - Dowty Rotol

AD/PR/37 Propeller Blades - Metallic Leading Edge Guard 10/2007 DM

Applicability:

Dowty Propellers - R408/6-123-F/17 propellers equipped with blade assemblies Part Number (P/N) 697071200-18, 697071210-18, 697071227-18, 697071240-18, 697071245-18 and 697071257-18 where the bonded metallic leading edge (L/E) guard has accumulated 1,200 Flight Hours (FH) or less since installation.

Note 1:  These propellers are known to be installed on, but not limited to Bombardier (formerly de Havilland) Dash 8 Series 400, 401, and 402 aircraft.

Requirement:

Inspect the identified blade assemblies in accordance with the instructions of Dowty Propellers Alert Service Bulletin (ASB) No. D8400-61-A69 initial issue dated
15 August 2007 or later EASA approved revisions.

Note 2:  EASA Emergency Airworthiness Directive (AD) No. 2007-0223-E dated
15 August 2007 refers.

Compliance:

Within the next 50 FH or within 1 month after the effective date of this AD, whichever occurs first; and repetitively thereafter at intervals not to exceed 100 FH, until the bonded blade L/E guard has accumulated more than 1,200 FH since installation.

This Airworthiness Directive becomes effective on 20 August 2007.

Background:

Three in-service propellers have been found to have blades which have lost the bonded metallic leading edge guard.  If the leading edge guard comes off as the propeller turns, it could cause secondary damage to aircraft or injury to personnel.

This Airworthiness Directive (AD) mandates repetitive inspections of the blade L/E guards for correct bonding until they accumulate more than 1,200 FH time in service.

Charles Lenarcic
Delegate of the Civil Aviation Safety Authority

16 August 2007