AD/Premier/7 Hydraulic Pump Fitting (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/7 Hydraulic Pump Fitting 1/2009

Applicability:

Hawker Beechcraft Corporation (HBC) Model 390 aeroplanes, serial numbers RB-4 through RB-224.

Requirement:

1.    Remove current preformed packing (part number (P/N) MS28778-6), elbow fitting (P/N MS21908J6), and jam nut (P/N AN924-6J) from the left and right hydraulic pump pressure output port and install new preformed packing (P/N MS28778-6), union (P/N MS21902J6), and swivel fitting (P/N NAS1762J0606) in the left and right hydraulic pressure pump output port, in accordance with Hawker Beechcraft Mandatory Service Bulletin SB 29-3869, dated January 2008 or later FAA approved revision.

2.    Install hydraulic pump case drain check valve Kit No. 390-5803-0001 in accordance with Hawker Beechcraft Mandatory Service Bulletin SB 29-3851, dated January 2008 or later FAA approved revision.

Note:  FAA AD 2008-23-13 Amdt 39-15734 dated 5 November 2008 refers.

Compliance:

Within the next 200 hours time-in-service (TIS) after the effective date of this AD or within the next 6 months after the effective date of this AD, whichever occurs first.

This Airworthiness Directive becomes effective on 15 January 2009.

Background:

This AD results from nine occurrences of hydraulic fluid leaking from the engine hydraulic pump output fitting as a result of an improperly installed elbow connecting the output port to the pulse dampener hose.  The issuing of this AD is intended to prevent hydraulic fluid leaking from the left and right hydraulic fluid pump and to prevent the flow of hydraulic fluid into the engine compartment.

The loss of hydraulic fluid can result in loss of aeroplane hydraulic system pressure and the consequent loss of hydraulic system functions including gear extension/retraction, spoiler functions, and anti-skid braking system actuation.  The inability of the hydraulic installation to isolate flow of hydraulic fluid could result in a hazardous amount of flammable fluid in the corresponding engine compartment.  These conditions, if not corrected, could result in loss of system functions and/or fire in the engine compartment.

James Coyne
Delegate of the Civil Aviation Safety Authority

28 November 2008