Cathay Pacific Airways and Dragonair planned to have all 15 of their Airbus A330-300s back in service by 7 June, after completing gearbox modifications to the twinjet's Rolls-Royce Trent 700 engines.
R-R and Cathay had completed 25h of ground and flight testing of the Hispano-Suiza modification package on the Trent 700 by 4 June. The French Direction General de l'Aviation Civile (DGAC) and the UK Civil Aviation Authority have certificated the modifications.
The solution involves installing a modified oil feed on the cover plate of the step aside gearbox. The modification, based on the proven Trent 800 design, better directs the flow of oil to the driveshaft bearing. The improved oil feed cuts operating temperatures by 30% and reduces stress on the bearing.
Hong Kong Aero Engine Services, the overhaul company owned by R-R and Cathay's sister company HAECO,modified the gearboxes with kits from Hispano- Suiza. The gearboxes were then installed on the 14 A330s grounded at various airports around Asia, before they were ferried back to Hong Kong to resume services.
Cathay says that it does not plan to recommence extended-range twin-engine operations (ETOPS) until it has accumulated more flight time, and has discussed the matter with the Hong Kong Civil Aviation Department. The airline had previously been certificated to operate 138min ETOPS. The only route effected by the suspension of ETOPS is to Colombo, Sri Lanka, which adds an extra 1h.
The Trent-powered A330-300 has received clearance from the European Joint Aviation Authorities for 180min ETOPS operations, although there are no airlines in the region operating this engine/airframe combination.
JAA ETOPS is still officially in place, but the JAA says that its status is being examined, and will be on the agenda at an A330 review meeting scheduled to take place at Airbus Industrie's Toulouse headquarters on 17 June.
Cathay chairman Peter Sutch has reportedly stated that the grounding will cost the airline up to HK$150 million ($19.2 million). Both Hong Kong carriers are expected to press R-R and Hispano-Suiza for compensation.
Source: Flight International
