Cathay Pacific Airways has suffered a second inflight shutdown of a Rolls-Royce Trent 700 engine in fewer than seven days. As a result, clearance for extended-range twin-engine operations (ETOPS) has been suspended by the Hong Kong authorities.

The latest incident, involving an Airbus Industrie A330-300, occurred on 12 May during climb-out. Oil pressure dropped and the engine spooled down, forcing the crew to return and make a single-engined landing at Bangkok. A subsequent inspection of the engine's master chip detector (MCD) showed metal contamination.

As with the previous incident on 6 May, again involving a Cathay A330 on climb-out from Hong Kong, a bearing failure in the step-aside gearbox appears to be the cause of the shutdown (Flight International, 14-20 May). "There is no question-it's definitely a bearing. What's causing the bearing to suffer stress is unclear," says a senior Hong Kong airline source.

R-R's continuing investigation includes a check of lubricant oil and collating failed bearings in an effort to identify a possible rogue batch, but no explanation for the failures has yet been found. A step-aside gearbox containing bearings from a similar batch to those which failed has been sent to gearbox supplier Hispano-Suiza for tests, although R-R says that it does not believe that rogue bearings are the cause.

Cathay has now suffered three A330 engine shut downs, all under similar circumstances, since November 1996. Associate carrier Dragonair also suffered a Trent 700-powered A330 failure on 17 April, caused by carbon clogging an oil filter. Cathay then suspended its 120min ETOPS clearance, which the Hong Kong Civil Aviation Department has now made official.

The move does not affect Cathay operations to any major extent, other than flights to Colombo, Sri Lanka, which will have to be redirected to stay within 60min diversion time. Dragonair does not fly any ETOPS routes. Airbus and R-R have issued service bulletins telling operators of Trent 700-powered A330s to inspect engine MCDs every ten flight hours or every four cycles.

Source: Flight International