Inspections Required For Rolls-Royce Trent Series 900 Engines

EASA has issued an emergency AD for Rolls-Royce RB211 Trent 900 series engines, variants RB211 Trent 970-84, RB211 Trent 970B-84, RB211 Trent 972-84, RB211 Trent 972B-84, RB211 Trent 977-84, RB211 Trent 977B-84 and RB211 Trent 980-84 (all serial numbers) known to be installed on, but not limited to, Airbus A380 series airplanes.

The AD requires High Pressure / Intermediate Pressure (HP/IP) Structure Inspections.

The AD, 2010-0242-E, follows the uncontained engine failure which recently occurred on a Rolls-Royce Trent 900 involving release of high energy debris and leading to damage to the airplane. Analysis of the preliminary elements from the incident investigation shows that an oil fire in the HP/IP structure cavity may have caused a sequence of events leading to failure of the Intermediate Pressure Turbine (IPT) Disc.

This condition, if not detected and corrected, could result in additional uncontained engine failures, possibly leading to damage to the airplane and injury to persons on the ground. Pending conclusion of the investigation, EASA issued AD 2010-0236-E to require repetitive inspections of the Low Pressure Turbine (LPT) stage 1 blades and case drain, HP/IP structure air buffer cavity and oil service tubes in order to detect any abnormal oil leakage, and if any discrepancy is found, to prohibit further engine operation.

Since issuance of AD 2010-0236-E, the incident investigation has progressed and inspection data from in-service engines has been gathered and analysed. The results of this analysis show the need to amend the inspection procedure, EASA AD No: EASA Form 111 Page 2/3 retaining the inspection of the air buffer cavity and focusing on the oil service tubes within the HP/IP structure.

For the reasons described above, this AD partially retains the requirements of AD 2010-0236-E, which is superseded, and requires implementation of the amended procedure and accomplishment of the associated inspections.EASA says  The requirements of this AD are considered as interim action. If, as a result of the on-going incident investigation, a terminating action is later identified, further mandatory actions might be considered.

FMI: www.easa.europa.eu