The pilot of TransAsia Airways Flight 235 said "mayday, mayday, engine flameout" moments before the propjet banked sharply and crashed into a Taipei river.

Video images of the plane's final moments in the air captured on car dashboard cameras do not appear to show any flames as it turned sharply, with its wings going vertical and clipping a highway bridge before plunging into the Keelung River yesterday, killing at least 31 people.

Fifteen people were injured, and the search continued for 12 people still missing.

Taiwan's Civil Aeronautical Administration released a snippet of audio including the pilot's mayday call, and an agency official confirmed the mayday distress call today, but did not say how it might relate to a cause for the crash.

Both the administration and the airline, Taipei-based TransAsia Airways, declined to speculate on causes for the crash at about 10.55am local time near the capital city's central airport.

The plane's black box was found overnight. The pilots' bodies have not yet been recovered.

The ATR 72 propeller jet suddenly banked 90 degrees within two minutes of takeoff and descended on its side into the Keelung River. It clipped a bridge and a taxi moments before the crash.

Relatives of some of the 31 passengers from China will reach Taipei on a charter flight this afternoon.

Among the survivors was a family of three, including a prematurely born boy whose heart stopped beating after three minutes under water. He recovered after receiving CPR, his brother Lin Ming-yi told reporters.

About 10 Taipei fire agency divers are looking for any more bodies that may be at the cold river bottom. The fuselage, largely dismantled by hydraulic rescue tools, has been moved to a riverbank alongside recovered luggage.

Another ATR 72 operated by the same Taipei-based airline crashed in the outlying Taiwan-controlled islands of Penghu last July 23, killing 48 at the end of a typhoon for reasons that are still under investigation.

ATR, a French-Italian consortium based in Toulouse, France, said it was sending a team to Taiwan to help in the investigation.

The ATR 72-600 that crashed yesterday is the manufacturer's best plane model, and the pilot had 4,900 hours of flying experience, said Lin Chih-ming of the Civil Aeronautics Administration.