Qantas jet ‘lucky’ after power loss

A Report in The Age says that the pilot of a Qantas flight which lost power on approach to Bangkok airport was lucky the outage occurred when the plane was close to landing, an aerospace engineering expert said.

QF2 – a Boeing 747 – lost power from all four of its main generators 15 minutes away from Bangkok, and the pilot was forced to switch to battery back-up for the landing, according to the Australian Transport Safety Bureau.

There were 343 passengers on board, all of whom landed safely in Sydney three days after leaving London.

The Director of Aerospace at RMIT University in Melbourne, Dr Arvind Sinha, said that while the jumbo’s engines and steering would not have been affected, there was only an hour’s worth of back-up power for its navigation and communication system, which were essential to landing.

“If the standby power went off he had about one hour to get the aircraft back before landing becomes an issue,” Dr Sinha said.

“In this case it looks as if it has gone to the last stage of emergency power for communication and navigation.”  “After that it comes down to the skill and experience of the crew.”

“The engines have their own independent power source and the steering is operated by a hydraulic pump system, but the critical issues are the navigation and communication systems that you need to find your way to a runway to land.”

Dr Sinha said that the total failure of all four generators on a Boeing 747 was “unheard of”.

“It looks as if it is a technological failure rather than a human error – whether that be materials, design or manufacturing.”

Qantas Executive General Manager John Borghetti said the incident was triggered by water entering the generator control unit, which caused loss of power.

“The aircraft was subjected to stringent inspections and testing in Bangkok before being cleared to fly,” he said.

He said the incident was being further investigated and the entire B747-400 fleet has been inspected.

Boeing would notify all other airlines of the incident.

Australian Transport Safety Bureau deputy director of aviation Julian Walsh said that if the power failure had occurred further away from an airport there could have been a serious accident.

“Obviously there’s a limit to the battery power that’s available,” Mr Walsh said.

Passengers coming off the flight at Sydney Airport expressed irritation with the delay but praised Qantas for putting safety first.

Chloe Washbrook and Katherine Radding, both 25 from London and who flew for a holiday in Australia, said they first became aware of the jet’s problems on approach to Bangkok.

“We just got told that there was a slight power failure,” Ms Washbrook said.

Once the passengers got off at Bangkok they were told there might be a slight delay but then were eventually told they would be put up overnight and they should return to the plane to collect their belongings as the jet’s emergency battery took 16 hours to recharge.

“When we had to go back on the plane to get our stuff, the Qantas cabin crew were asking us what was going on, so we had to tell them that the plane was being delayed for a day,” she said.

Passengers were given a free night in a hotel and were told they could spend up to 2000 baht ($63) for underwear and a change of clothes, which Qantas would reimburse, Ms Washbrook said.

The delay was slightly more problematic for Martin and Karina Guenzl and their three young daughters.

“It was a long, long trip,” a dishevelled Mr Guenzl, 38, said at Sydney Airport.

“It was a bit of a marathon, it finished with our little one being sick right at the end of the flight into Sydney.”

A Report by The Mole from The Age