AirAsia flight QZ8501

An AirAsia Airbus A320-200 disappeared during a flight from Indonesia to Singapore. The plane lost contact after its pilot failed to get permission to fly higher to avoid bad weather.

Updated: 16 January 2015

The route

Altitude of other aircraft

QZ8501 was flying lower than other airliners in the vicinity, including two other AirAsia jets on a similar route.

QZ8501 was flying lower than other airliners in the vicinity, including two other AirAsia jets on a similar route.

The debris field

A projection by Indonesia's national search and rescue agency shows how the debris would have spread east.

Hazards to aircraft

Aerodynamic stalls

To produce lift, there must be a smooth airflow around the wing. Lift overcomes the weight of the aircraft keeping it in the air.

When a wing stalls, lift will no longer be produced. As the aircraft’s weight is unopposed, it will fall towards the ground. With sufficient altitude, stall recovery can be obtained.

Instruments prone to icing


Lasting from only a few seconds to a couple of minutes and measuring less than 4 km in size, microbursts can produce extremely strong wind shear, posing great danger to passing aircraft. However, microbursts are common at lower altitudes and not as common at cruising height.

1Plane encounters head winds that increase airspeed. The pilot normally counters this by reducing power.

2As the aircraft then encounters a downdraft followed by a tail wind. This can cause a rapid reduction in lift and airspeed.

3Pilots exit by increasing power but if the wind shear is strong enough, the plane could encounter serious problems.

Aviation safety

The loss of flight QZ8501 would cap one of the deadliest years in civil aviation for almost a decade. Even before this latest incident, some 762 people had lost their lives this year. However, the statistics also show a record-low number of fatal crashes.



A rare loss

A statistical analysis of commercial aviation accidents by Boeing found that fatal accidents are most common when the plane is taking off or landing, not cruising.

Notes: Locations of flight data sensors and recorders are approximate. Illustrations of transmitter and recorders show widely used models supplied by Honeywell International.

Sources: FlightRadar24; Basarnas; Aviation Safety Network; Boeing; Honeywell; BEA (Bureau d'Enquetes et d'Analyses pour la securite de l'aviation civile); Australian Maritime Safety Authority; Lockheed; MetOcean; Ocean Surface Current Analyses Real-time (OSCAR), Earth & Space Research; Reuters.

Graphics by Simon Scarr, Wen Foo, Fabian Chan, Gustavo Cabrera, Jane Pong, Christine Chan and Chris Inton