Investigators on Tuesday retrieved the flight data recorder from a Bangladeshi passenger plane that crashed in Kathmandu, killing at least 49 people on board and injuring at least 22.

"The flight data recorder has been recovered; we have kept it safely," said Raj Kumar Chettri, general manager at Tribhuvan International Airport.

Witnesses said US-Bangla Airlines Flight BS211 flew unsteadily as it twice circled the airport before bursting into flames as it tried to touch down on Monday.

Read more: Dozens killed in Kathmandu plane crash

The airplane had taken off from the Bangladeshi capital of Dhaka with 71 passengers — 32 from Bangladesh, 33 from Nepal and one each from China and the Maldives. Authorities have not disclosed the nationalities of the crew members.

The pilot is among the injured being treated at a nearby hospital. He is reportedly a former air force officer with more than 1,700 hours flight time in the Bombardier Dash 8 type aircraft that crashed.

Read more: Plane crashes in western Nepal

Unclear blame

US-Bangla Airlines and airport authorities have blamed each other for the accident.

The airport's general manager, Raj Kumar Chetri, said the pilot failed to heed the control tower and tried to land on the airport's only runway from the wrong direction.

But the CEO of US-Bangla, Imran Asid, said: "we are suspecting that Kathmandu ATC tower might have misled our pilots to land on the wrong runway," adding: "we assumed that there was no negligence by our pilots."

Read more: Wreckage of Nepal plane crash found on mountainside

Confusing recording

Air traffic tracking website LiveATC.net posted an audio recording of the moments before the crash.

In it, the pilot asks for permission to land from the north and, less than a minute later, to land from the south. The air traffic controller grants both requests.

But just before landing, the pilot says: "Are we cleared to land?" The controller says seconds later: "I say again, turn!" before ordering firefighters to make their way to the runway.

The crash is the worst air accident since a Pakistan International Airlines passenger plane crashed at Kathmandu in 1992, killing 167 people.

Read more: TransAsia crash adds to air safety concerns

amp/rc (AP, Reuters)

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