AD/BN-2/84 Pitot/Static Pressure Head (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.

Pilatus Britten-Norman BN-2 Series Aeroplanes

AD/BN-2/84 Pitot/Static Pressure Head 2/2006 DM

Applicability:	All model BN2, BN2A, BN2B, BN2T, BN2T-4R and BN2T-4S Islander series aeroplanes.
Requirement:	1.    Perform the inspection procedure and the leak test procedure as detailed in, Section 6 Action, of B-N Service Bulletin 310 Issue 1 dated 10 October 2005 or later revision approved by the United Kingdom Civil Aviation Authority.
2.    Perform a check of the drain traps for moisture.
Note:  CAA(UK) AD G-2005-0034 (EASA Approval 2005-6447) refers.
Compliance:	For Requirement 1 - Prior to 1 February 2005 and thereafter at intervals not exceeding 500 hours time in service (TIS).
For Requirement 2 - Initially within 500 hours TIS after the Requirement 1 inspection and thereafter at intervals not exceeding 500 hours TIS.
This Airworthiness Directive becomes effective on 23 December 2005.
Background:	Incidences have been reported to B-N Group where cracks have been found in the inner shell of the pitot/static pressure heads.  This could result in incorrect readings on the pressure instrumentation (eg altimeters, vertical speed indicators (rate-of climb) and airspeed indicators).  This condition has been determined to be potentially hazardous.

Charles Lenarcic
Delegate of the Civil Aviation Safety Authority

20 December 2005