The carrier is investigating the incident with Rolls-Royce and Airbus

Singapore Airlines said no ‘anomalies’ were detected in either engine

Plane landed safely in Shanghai and flew back to Singapore after a delay

Pilots followed 'operational procedures' to restore power to the engines

The Airbus A330-300 was flying from Singapore to Shanghai on Saturday

Passengers received a scare when a Singapore Airlines jet dropped 13,000ft after both of its engines failed in mid-air on a recent flight.

The carrier has launched an investigation to determine what caused the engines to lose power after encountering bad weather while en route from Singapore to Shanghai.

As the Airbus A330-300 made an unexpected descent the pilots followed ‘operational procedures’ and managed to restore power to both Rolls-Royce Trent 772 engines, Singapore Airlines said in a statement.

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The pilots followed 'operational procedures' and restored power to the Airbus A330's Rolls-Royce engines

Flight SQ836 was carrying 182 passengers and 12 crew members, when the jet engines lost power three-and-a-half hours into Saturday’s five-hour journey.

The airline told MailOnline Travel: 'Both engines experienced a temporary loss of power, although one engine returned to normal operations almost immediately.

'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 continued normally to Shanghai and touched down uneventfully at 10:56pm local time.'

Singapore Airlines said no ‘anomalies’ were detected in either of the engines when they were 'thoroughly inspected and tested' upon arrival in Shanghai, and that it is investigating the incident with Rolls-Royce and Airbus.

Data from FlightRadar24.com and a report in the Aviation Herald revealed the plane was cruising at 39,000ft over the South China Sea, about 162 miles from Hong Kong, when it ran into trouble.

The jet dropped to 26,000ft before power was restored, and climbed back to 31,200ft before it made its normal descent and landed safely in Shanghai about one hour and 40 minutes later, the report said.

The plane later took off to return to Singapore after a two-hour delay, the Aviation Herald reported.

The Air Accident Investigation Bureau of Singapore said it has been informed and is taking the lead on the investigation.

After landing safely in Shanghai the plane was inspected and then departed for Singapore (file photo)

A spokesperson told Channel News Asia: ‘As the occurrence happened in international waters the AAIB will be the authority for investigating this incident.

‘The AAIB is in the midst of gathering information and flight data from the operator.’

A pilot told Reuters it is extremely rare for a plane to lose power in both engines, but flight crews are trained to handle such an incident.

An unidentified pilot with a Southeast Asian airline told the news agency: ‘We do occasionally lose power in one engine for various reasons, but you hardly ever lose both engines.

‘If that happens, you follow the procedures in your check-list and try to restart the engines. The pilots successfully did that here.’

The fact that the plane did not divert and continued to Shanghai suggests it may not have been a ‘very serious incident’, the pilot added.

Singapore Airlines is Asia’s third largest carrier by market value and currently has 30 Airbus A330-300s in its fleet and four more on order. Each plane has a passenger capacity of 285.

Last week Airbus warned of a technical bug potentially affecting the engines of its A400M military planes.