AD/Premier/4 Stall Warning System Angle-of-Attack Transmitters (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.

Hawker Beechcraft (Raytheon) 390 Series Aeroplanes

AD/PREMIER/4 Stall Warning System
Angle-of-Attack Transmitters 10/2008 DM

Applicability:	Model 390 aeroplanes, serial numbers RB-4 through RB-204.
Requirement:	1.    If not previously accomplished, incorporate Raytheon Aircraft Company (RAC) Temporary Change to the Approved Aircraft Flight Manual (AFM) part number (P/N) 390-590001-0003CTC7, issued: 15 March 2007, into the AFM.
2.    Carry out a post-flight check for residual heat in the both the left hand (LH) and right hand (RH) stall warning angle-of-attack (AOA) probes in accordance with the procedures in AFM Temporary Change P/N 390-590001-0003CTC7.
This check may be accomplished by the owner/operator who holds at least a private pilot licence who must make an appropriate entry in the aircraft Technical Records certifying completion of the check.
CAUTION: TO PREVENT POSSIBLE BURNS, USE EXTREME CAUTION TOUCHING HEATED AREAS.  TO CHECK HEATING AND AVOID BURNS, HOLD HAND NEAR HEATED AREA OR MOVE HAND GRADUALLY FROM AMBIENT AREA TOWARD HEATED AREA UNTIL WARMTH CAN BE FELT.
3.    If, as a result of the Requirement 2 check, residual heat is not detected carry out a post-flight maintenance manual operational test of the heat of the AOA probes in accordance with the procedures in AFM Temporary Change P/N 390-590001-0003CTC7 and Hawker Beechcraft Mandatory Service Bulletin SB 27-3787, issued: May 2007.
4.    If the AOA probe fails the Requirement 3 operational test replace the probe in accordance with the procedures in SB 27-3787.
5.    Replace or modify (upload software) the stall warning AOA transmitters by accomplishing one of the following actions in accordance with the procedures in SB 27-3787:
a.     Upload new software Kit No. 123-3436 (Field Software Upload SLZ8060-3,-4) to the AOA transmitters; or
b.    Replace any P/N SLZ8060-3 and/or P/N SLZ8060-4 AOA transmitters with new P/N SLZ8060-5 AOA transmitters.

6.    Remove AFM Temporary P/N 390-590001-0003CTC7 from the AFM.
7.    AOA transmitter P/N SLZ8060-3 or SLZ8060-4 that does not have the new upgraded software per Requirement 5.a. may not be installed as a replacement spare on any aeroplane.
Later revisions of SB 27-3787, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2008-16-02, are considered acceptable for compliance with the equivalent Requirements of this Directive.
Note:  FAA AD 2008-16-02 Amdt 39-15620 refers.
Compliance:	For Requirement 1 - Within 15 hours time-in-service (TIS) after 3 September 2008 (the effective date of this Directive) or within 30 days after 3 September 2008, whichever occurs first.
For Requirement 2 - Following every flight after AFM Temporary Change is inserted in accordance with Requirement 1 until Requirement 5.a. or 5.b. is accomplished.
For Requirements 3 and 4 - Before further flight.
For Requirement 5 - Within 250 hours TIS after 3 September 2008 or within 12 months after 3 September 2008, whichever occurs first.
For Requirement 6 - Following compliance with Requirement 5.a. or 5.b.
For Requirement 7 - As of 3 September 2008.
This Airworthiness Directive becomes effective on 3 September 2008.
Background:	The FAA has received reports of the potential for unannunciated loss of the heating function in the LH and RH stall warning AOA transmitters of Model 390 aeroplanes.  This Directive initially requires repetitive post-flight checks for residual heat in the AOA probes and, if necessary, maintenance manual operational test of the heat of the AOA probes.  The Directive also requires eventual replacement or modification (upload software) of the stall warning AOA transmitters and is issued to correct potentially inadequate stall warning with loss of stick pusher function.

James Coyne
Delegate of the Civil Aviation Safety Authority

1 August 2008