This 2009 photo shows a Henan Airlines plane, reported by China's news agency to be the same model of aircraft that crashed Tuesday at an airport in Heilongjiang province. (Xinhua/Associated Press)

Aviation officials at a relatively new airport in northeast China on Wednesday searched through debris for clues to why a passenger jet crashed while trying to land on a fog-shrouded runway, killing 42 people and injuring 54 others.

The Henan Airlines plane crashed late on Tuesday in a grassy area near the Lindu airport in the Heilongjiang province city of Yichun. The newly built airport in Yichun sits in a forested valley and has operated for a year.

There were 96 people on board including 91 passengers and five crew members. Survivors recounted scenes of horror, with luggage falling down and escapes through flames and broken holes in the fuselage.

The plane's two black boxes were recovered on Wednesday, the official Xinhua News Agency reported, but it is still not known what caused the accident.

Vice Prime Minister Zhang Dejiang arrived on Wednesday at the crash site to help set up an investigation team.

Most of the injured were brought to Yichun City Number 1 Hospital, which was under heavy security. Seven of the 54 survivors were severely injured, said Yichun mayor Wang Aiwen.

In the hospital intensive care unit, a mother and her two daughters — all badly injured — waited to be transferred to a better facility in a bigger city. All three have burns over large parts of their bodies and the mothers windpipe has been crushed after the incident.

Outside the children's aunt, Qu Guihong, spoke of her younger sister and the girls: "They'll never fly in a plane again. That is the first thing they said when we saw them: 'We'll never take a plane again.' And for the children that was their first time on a plane ever."

Other anxious relatives waited for reports on their injured loved ones as doctors assessed the injuries.

Most of the 54 survivors are expected to live.