AD NUMBER: 2004-23-03
MANUFACTURER: Rolls Royce SUBJECT: Airworthiness Directive 2004-23-03 SUMMARY: The FAA is adopting a new airworthiness
directive (AD) for Rolls-Royce plc (RR) RB211 Trent700 series
turbofan engines. This AD requires initial and repetitive borescope
inspections of the high pressure-and-intermediate pressure (HP-IP)
turbine internal and external oil vent tubes for coking and carbon
buildup, and cleaning or replacing the vent tubes if necessary.
This AD results from a report of a RB211 Trent 700 series engine
experiencing a disk shaft separation,overspeed of the IP turbine
rotor, and multiple blade release of IP turbine blades. Preliminary
findings suggest these events resulted from an internal oil fire in
the HP-IP turbine oil vent tubes due to coking and carbon buildup.
This fire led to a second fire in the internal air cavity below the
IP turbine disk drive shaft. We are issuing this AD to prevent
internal oil fires due to coking and carbon buildup, that could
cause uncontained engine failure and damage to the airplane.