An MH-60R helicopter, attached to the USS Sampson (DDG 102), approaches an Indonesian patrol vessel
An MH-60R helicopter, attached to the USS Sampson (DDG 102), approaches an Indonesian patrol vessel while searching for debris. Reuters/U.S. Navy

AirAsia Flight QZ8501 crashed into the Java Sea after it disappeared on Dec. 28. Here is what is believed to have happened before the crash.

Indonesian officials confirmed the crash of the airbus A320-200 which was carrying 162 people from Indonesia to Singapore. It lost contact due to bad weather only around 40 minutes after it started the journey. The flight took off from Surabaya at 05:35 local time on Sunday (22:35 GMT Saturday), BBC reports. The crew consisted of seven people, including four flight attendants, two pilots and an engineer. The 155 passengers included 16 children and one infant. While most of the passengers were from Indonesia, there was one man who had a British passport.

Bad weather prompted the pilot to ask for permission to fly higher. The pilot made contact with air traffic control at 06:12 local time (23:12 GMT). However, he was not immediately allowed to fly higher due to heavy air traffic in the area. According to AirAsia, the pilot asked to climb to 38,000 ft from 32,000 ft to avoid big storm clouds. This is a common occurrence in the area. Indonesia's weather agency says the storm clouds rose to a height of 44,000 ft. This is higher than commercial airlines in the region usually fly.

However, later there was no answer when air traffic control tried to contact the plane which disappeared from radar screens shortly afterwards. The officials, on the other hand, did not issue a distress signal. It was learned that the plane was near the equator known for thunderstorms, where trade winds from the southern and northern hemispheres intersect. The flight was reported to be the lowest-flying plane in the region when it disappeared.

According to Australian-based aviation security expert Desmond Ross, it was "possible and maybe even likely" that the thunderstorm caused the plane to crash even though it would be impossible to be "100 per cent certain" to determine it. "It could possibly have been a mechanical failure or an explosion," The Sydney Morning Herald quotes Ross, "It could have been some catastrophic failure which caused it. Coincidences happen."

The debris of the AirAsia flight as well as bodies was discovered on the third day of the search around 16km from the plane's last known co-ordinates.

Contact the writer: s.mukhopadhyay@IBTimes.com.au