Bangui - The only crew member who survived the crash of a Boeing 707 in this central African country said on Sunday that pilot error may have contributed to the accident that killed 23 people.

From his hospital bed, Congolese engineer Laurent Tabako says that the crew may have dumped too much fuel before attempting an emergency landing on Thursday at Bangui airport.

Dumping fuel is standard procedure before attempting such a landing. But Tabako said the engines stopped before the plane reached the runway, suggesting it may have run out of fuel.

Witnesses said they didn't hear the usual engine noises when the plane crashed and saw no flames when it broke into pieces.

"I cannot say for sure if the crash occurred because of the lack of fuel or not. Only the black boxes can say more about it," said Tabako, who suffered injuries to the head and leg.

He said the plane experienced no major difficulties after it took off from N'Djamena in Chad on route for Brazzaville in Republic of Congo.

"The only reason why we wanted to land in Bangui was that the wheels wouldn't pull back after we took off from N'Djamena," he said.

Air officials did not immediately comment on Tabako's allegations.

The government of the Central African Republic has launched an investigation to determine the cause of the crash.

The plane's black box flight data and voice recorders have been recovered and will be sent to France for analysis, according to officials with the regional air authority, Asecna.

The cargo plane crashed just 4km short of the runway, in a fishing community on the outskirts of the capital.

Only the engineer and one passenger survived and were hospitalised with serious injuries. There were no reports of casualties on the ground.

The injured passenger, a woman from Chad, remained in a serious condition on Sunday with injuries to the head, chest and legs, hospital officials said.

The jet was carrying a load of onions and garlic along with 17 Chadian passengers, air officials said. There were eight crew members on board.

The plane, which was operating under the licence of Prestige Airlines in Republic of Congo, was owned by New Gomair, a small airline run by a group of Goma businessmen in neighbouring Congo.

Central African Republic, a former French colony, is one of the world's poorest countries. - Sapa-AP