The door was not properly fastened, according to one survivor
A team of Ukrainian experts has left for the Democratic Republic of Congo to help local inspectors with their inquiry into an air accident last Thursday.
A Ukrainian-chartered Ilyushin transport plane lost its cargo door at 30,000 feet, causing the aircraft to lose pressure, sucking many passengers out.
There have been conflicting reports about the number of casualties.
The Congolese Government initially said seven people had died in the accident; the defence minister later said many more could have been killed.
Some reports said 170 people had lost their lives.
The Ukrainian team, headed by the defence ministry's head of flight security, has been asked to find out the exact number of casualties and to help speed up the inquiry into the circumstances of the crash.
Passengers were sucked out of the plane when the rear doors flew open after taking off from the capital Kinshasa on Thursday night.
The Ukrainian plane had been chartered by the military to fly from Kinshasa to Congo's second city, Lubumbashi.
Following the incident, the Russian crew was able to turn the Ilyushin 76 around and land at Kinshasa airport.
The Information Minister, Kikaya Bin Karubi, told Reuters an investigation was being carried out by the air force and army to identify whether the accident was the result of human error or a mechanical problem.
Survivors told how they had clung to bags, ropes and nettings for almost two hours to stop themselves also being dragged through the rear hole.
Mambaza, a policeman, estimated there were 350 passengers on board - including 100 women and children. He thought no more than 100 had returned.
"When the back door opened, I fell down and lots of boxes covered me," he told Associated Press news agency from a military hospital in the Congolese capital, Kinshasa.
"Lots of my colleagues were sucked out by the wind. I don't know how many, because I fainted."
His wife, Bebe Kahoma, said: "Us women, we had a little bit of luck because we had been placed close to the cabin, therefore far from the door, but we sustained some damages."
Recent African air accidents
6 March 2003: An Algerian Boeing 737 crashes after taking off from the remote Tamanrasset airport, leaving up to 102 people dead
4 July 2002: A Sudan Airways plane crashes into a residential district of Bangui, capital of the Central African Republic, killing 23 people
7 May 2002: An EgyptAir Boeing 735 crash-lands near Tunis with 55 passengers and up to 10 crew on board, killing 15
4 May 2002: A BAC1-11-500 plane crashes in the Nigerian city of Kano, killing 148 people - half of them on the ground
She said an unknown number of women and children had fallen from the plane and the shock had caused two pregnant women to miscarry.
Other unnamed survivors, recovering at the Lufungula military camp, described the scene on board to the French news agency, AFP.
"There were no seats, only a few folding chairs along the cabin walls. People were crammed onto benches and on the floor," said one.
"When the door came off, the plane tipped to the right then to the left, and many people fell towards the hole."
Saved by ladder
He said he had stayed alive by gripping onto the netting that had secured trunks of ammunition and uniforms.
"It was by clinging with my arms and legs to the netting that I managed not to be sucked out like the others," he said.
Sergeant Kabmba Kashala said the plane had taken off with the door improperly fastened.
It flung open after three failed attempts to fully shut it mid-flight, he said.
"I was just next to the door and I had the chance to grab
onto a ladder just before the... door let loose," he