British Aerospace BAe 125 Series Aeroplanes 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 39.1 (1) of CAR 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. AD/HS 125/164 Pitot/Static and Stall Vent Drain Valves 1/2001 Applicability: Model DH.125, Model HS.125, Model BH.125, Model BAe.125, Model Hawker 800, Model Hawker 800XP, and Model Hawker 1000 series aeroplanes; as listed in Raytheon Aircraft Service Bulletin SB 34-3207, dated August 1999; excluding those aeroplanes on which all pitot/static drain vent valves have been modified with an insert in accordance with Raytheon Aircraft Repair Design Office instructions. Requirement: 1. Drain the pitot/static and stall vent drain valves, then perform a leak test of the systems, in accordance with SB 34-3207. 2. If, as a result of the Requirement 1 drain check, all drain valves are found to be operative, but any valve does not pass the leak test, accomplish one of the following actions: 1. apply a temporary seal of the drain valve(s) in accordance with Raytheon Aircraft SB 34-3223, dated August 1999; or b. replace the drain valve components with new or serviceable drain valve components in accordance with SB 34-3207 and perform a leak test in accordance with SB 34-3207; or c. modify the drain valves in accordance with Raytheon Aircraft SB 34-3282, dated August 1999. Modification of ALL the drain valves in accordance with SB 34-3282 constitutes terminating action for the requirement to perform repetitive leak tests. 3. If any drain valve was sealed in accordance with Requirement 2.a., either Requirement 2.b. or 2.c. must be accomplished. 4. If, as a result of the Requirement 1 drain check, any drain valve is inoperative (eg. plugged or taped), whether or not any leaking is detected, disassemble the valve and clean all obstructions in accordance with SB 34-3207 and perform a general visual inspection for corrosion of the drain valve. COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Note 1: For the purposes of this Directive, a general visual inspection is defined as: "A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight, and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked." 5. If no corrosion of the drain valves is detected during the Requirement 4 inspection, accomplish either of the following actions: 1. perform a leak test in accordance with SB 34-3207; or b. modify any inoperative valve in accordance with SB 34-3282. Modification of ALL the drain valves in accordance with SB 34-3282 constitutes terminating action for the requirement to perform repetitive leak tests. 6. If any drain valve is found to be corroded during the Requirement 4 inspection, inspect the connecting tubing for corrosion and replace any corroded valve or tubing with a new or serviceable valve or tubing in accordance with SB 34-3207. Then accomplish either of the following actions: 1. perform a leak test in accordance with SB 34-3207; or b. modify any replaced drain valve in accordance with SB 34-3282. Modification of ALL the drain valves in accordance with SB 34-3282 constitutes terminating action for the requirement to perform repetitive leak tests. Note 2: FAA AD 2000-22-03 Amdt 39-11949 refers. Compliance: For Requirement 1 - Within 300 hours time in service (TIS) after the effective date of this Directive and, if all valves are found to be operating correctly, repeat the leak test at intervals not to exceed 300 hours TIS until all drain valves are modified. For Requirement 2 - Before further flight and, if action specified in either Requirement 2.b. or 2.c. is accomplished, repeat the leak test at intervals not to exceed 300 hours TIS until all drain valves are modified. For Requirement 3 - Within 300 hours TIS after Requirement 2.a. was accomplished. For Requirement 4 - Before further flight. For Requirement 5 - Before further flight and thereafter repeat the leak check at intervals not to exceed 300 hours TIS until all drain valves are modified. For Requirement 6 - Before further flight and thereafter repeat the leak check at intervals not to exceed 300 hours TIS until all drain valves are modified. This Airworthiness Directive becomes effective on 25 January 2001. Background: This Directive requires leak checks and inspections for corrosion of the pitot/static and stall vent drain valves and, if necessary, replacement of certain components. These actions are intended to prevent erroneous altimeter and airspeed indications due to plugged or taped pitot/static and stall vent drain valves. Eugene Paul Holzapfel Delegate of the Civil Aviation Safety Authority 11 December 2000 The above AD is notified in the Commonwealth of Australia Gazette on 20 December 2000.