A serious attempt was underway late on Saturday afternoon to lift the tail section of the downed AirAsia flight QZ8501 from the sea bottom, after teams of divers managed to attach a giant orange balloon to the wreckage.

The international search and rescue team has two balloons capable of lifting 35 tonnes, and four others with lifting power of 10 tonnes each.

Searching for the main fuselage ... An Indonesian rescue helicopter flies over the Crest Onyx ship as divers search below. Credit:Reuters

It's hoped they will be able to bring the key piece of wreckage to the surface to allow a thorough search for the "black box" flight recorder which is usually stored in the tail.