The Australian Transport Safety Bureau (formerly the Bureau of
Air Safety Investigation) recommends that the Civil Aviation Safety
Authority review Rolls Royce RB211-524D4 engine cold stream nozzle
inspection criteria to minimise the possibility of failure during
operation
CASA agrees with ATSB recommendation R20000010. CASA Technical
Specialists have consulted with Rolls Royce Australia and Qantas
Powerplants Engineering on this subject. Advice received
included:
Rolls Royce has issued Non Modification Service Bulletin 78-C955.
NMSB 78-C955 details an on-wing cold stream nozzle inspection
procedure. CASA is confident that compliance with NMSB 78-C955 will
alleviate concern for the airworthiness of the RB211-524D-4 cold
stream nozzle.
Qantas has carried out an inspection of all RB211-524D-4 engines in
accordance with the procedures detailed in NMSB 78-C955. That
inspection program has identified a number of defects. Defect
rectification action has now been completed.
To ensure the continued airworthiness of RB211-524D-4 engines in
service in Australia, CASA is preparing Airworthiness Directive
AD/RB211/22 "Cold Stream Nozzle Inspection". AD/RB211/22 will
mandate compliance with NMSB 78-C955. UK CAA AD 005-01-2000
refers.
CASA is satisfied the action taken by the Authority, Rolls Royce
and Qantas adequately addresses the safety concern identified in
the ATSB report on Occurrence 199906038 dated 7 January 2000.
