PUBLISHED : Thursday, 16 September, 1999, 12:00am
UPDATED : Thursday, 16 September, 1999, 12:00am

A power blackout which delayed three flights and disrupted services at the airport passenger terminal for about 90 minutes last month caused another failure eight days later, it was revealed last night.

CLP Power released a report into the incidents, the first major disruption to services at Chek Lap Kok since its disastrous opening in July last year, which said the blackouts were related.

The first blackout occurred on August 17 in an airport substation when a broken vacuum bottle produced a 'flashover' and smoke during a switching operation, it said.

The power company said the loss of vacuum in a circuit breaker bottle was 'extremely rare'. Failure rate in factory tests for the vacuum bottles was less than 0.0003 per cent - or a one in 333,333 chance.

'This is the first incident of failure since the equipment was introduced into CLP's network in 1991,' it said.

CLP Power would now test all vacuum bottles from the same order as that which failed.

The problem had a knock-on effect, causing a malfunction on August 25 when a two-minute blackout knocked out lighting and baggage handling systems for up to 30 minutes.

The first blackout left the passenger terminal without power for 17 minutes until backup generators were turned on and proper supply resumed more than three hours later.

Legislators criticised the delay. CLP Power said a liaison group had been set up with the Airport Authority to review emergency procedures.