COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Cessna 550 (Citation II) Series Aeroplanes
AD/CESSNA 550/18 Brake Shuttle Valve 5/90
Applicability: Model 550 and 551 with unit number -0002 through -0619 and -0621 through -0623 equipped with BF Goodrich brakes.
Model S550 with unit number -0001 through -0160 incorporating SB S550-32-7, BF Goodrich brakes and wheels installation.
Requirement: 1. For model 550 and 551:
Inspect in accordance with Cessna alert Service Letter SLA 550-32-38.
For model S550:
Inspect in accordance with Cessna Alert Service Letter SLA S550-32-15.
2. Replace brake shuttle valves in accordance with BF Goodrich Service Bulletin SB 517.
Compliance: 1. Within 50 hours time in service after 17 May 1990 and thereafter at intervals not to exceed 50 hours time in service, until BF Goodrich SB 517 is incorporated.
2. Within 200 hours time in service after 17 May 1990.
Background: Reports of leaking shuttle valves have been received by the manufacturer. Leakage has been attributed to slow deterioration of shuttle valve o-ring material as a result of exposure to an incompatible seal lubricant.