COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Beechcraft 200 (Super King Air) Series Aeroplanes AD/BEECH 200/34 Oxygen System 8/81 Applicability: All models with S/Nos. BB-2, BB-6 to BB-185, BB-187 to BB-202, BB-204 to BB- 269, BB-271 to BB-407, BB-409 to BB-468, BB-470 to BB-482, BB-483 to BB-488, BB-490 to BB-509, BB-511 to BB-518, BL-1, BL-2 and BT-1 to BT-7, not modified in accordance with Beech SI No. 0867-341 Revision II. Requirement: 1. Fabricate a placard using letters at least 3 mm high to read as follows: "Flight above 25,000 feet prohibited unless the oxygen system is ARMED (ON)". 2. Install this placard in clear view of the pilot and operate the aircraft in accordance with this limitation. Note: FAA AD 80-09-03 R1 refers. Compliance: Within the next 100 hours time in service after 31 August 1981. Background: Overseas experience has shown that this requirement is necessary to prevent seizure and binding of the oxygen control cable due to freezing of contaminating moisture which will interfere with activation of the oxygen system.