Rolls Royce Revises Service Bulletin On Trent 900 Engine

In the ongoing Australian Transportation Safety Bureau (ATSB) investigation of an engine failure involving a Qantas A380 aircraft over Batam Island, Indonesia on 4 November 2010, the ATSB issued a safety recommendation that identified a potential manufacturing defect with an oil tube connection to the high-pressure (HP)/intermediate pressure (IP) bearing structure of the Trent 900 engine installed in some A380 aircraft.

That recommendation has prompted Rolls-Royce to immediately issue Revision One to the non-modification service bulletin (NMSB) 72-G595 incorporating assessment and engine rejection criteria for the measurement of potential oil feed stub pipe counter-bore misalignment, and a tightening of the compliance time frame from 20 to 2 flight cycles.

Since the issue of that bulletin, 45 Trent 900 engines have been inspected, and of those engines:

• 29 engines were installed on operating aircraft
• 8 engines were not installed on aircraft
• 4 engines were due to be delivered on a new aircraft
• 4 engines were on a flight test aircraft.

Three engines failed the inspection and were removed from service for further examination.  All Qantas aircraft engines currently flying had no defects recorded and remain in service.
 
 

ATSB Image

In addition, the European Aviation Safety Agency (EASA) approved software updates to the Rolls-Royce plc change to the engine electronic control system has now been incorporated in all operating aircraft. The software upgrade predicts intermediate turbine overspeed events and shuts the engine down before a turbine disc failure occurs.

FMI: www.rolls-royce.com, www.atsb.gov.au