Passengers and crew on a Shanghai-bound Singapore Airlines (SIA) flight had a mid-air scare last Saturday when both the plane's engines suddenly lost power during bad weather.
The incident, which pilots said was almost unheard of in SIA's history, happened at 39,000 feet about 31/2 hours after Flight SQ836, operated by an Airbus A330-300, left Changi Airport.
One engine powered up on its own "almost immediately" while pilots managed to restart the second one, said SIA.
A spokesman said: "The pilots followed operational procedures to restore normal operation of the second engine by putting the aircraft into a controlled descent, before climbing again."
The flight, with 182 passengers and 12 crew on board, continued its journey to Shanghai and touched down without any incident at 10.56pm local time.
The engines were thoroughly inspected and tested upon arrival in Shanghai but no anomalies were detected, he said. "We are reviewing the incident with Rolls-Royce and Airbus."
Aviation safety is in the spotlight after a series of incidents this year and last.
Pilots and aviation experts told The Straits Times it is rare for engines to stop working during flight. One reason could be bad weather, namely thunderstorms and tall clouds called cumulonimbus, which result in the build-up of ice crystals that could cause the plane's engines to stall.
A pilot from an Asia-based airline, who declined to be named, said weather conditions between Hong Kong and China can get "quite bad and bumpy" during this time of the year.
When the engine stalls, pilots typically have to push the plane's nose down at a pitch angle of about 10 degrees to recover from the stall.
"You don't want to dive fast but more like let it glide... but the manoeuvre can be quite abrupt, like applying an emergency brake," said a pilot who has flown for 14 years. It might have taken the pilots three to five minutes to restart the plane and get it to climb again, he said.
The A330 jet in question was delivered to SIA on March 30, according to Ascend Flightglobal Consultancy.
The jet's Rolls-Royce Trent 700 engines are also configured the same way as those of the other 30 A330s in the SIA fleet, said Mr Greg Waldron, the Asia managing editor of aviation magazine Flightglobal.
"It's quite surprising that such an incident can happen to a brand-new aircraft, even if it is flying in bad weather," said Mr Waldron. "Everything in the engine is built with very high engineering tolerance to withstand tonnes of rain and icing."
This article was first published on May 28, 2015.
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