By Wendy da Costa and Alex Eliseev
The plane that crash-landed on a school field near Durban International Airport had a clean bill of health and had flown only about 50 hours since its last service.
So what caused SA Airlink flight 8911 to abandon take-off and plummet into a built-up area 400m into its journey?
Speaking on television and radio yesterday, SA Airlink CEO Rodger Foster said investigators had retrieved the plane's black box recording devices and would study them to "get to the bottom of this".
Foster said that Airlink had been flying the aircraft, a Jetstream J41, since 1995 and it had reached "mid-life status" - with about 30 000 hours left before being retired.
Airlink had 15 of the aircraft.
Foster said that, according to regulations, the aircraft's engines had been overhauled and serviced after 9 000 flying hours, and inspections had been carried out after every 1 000 hours.
The aircraft had flown the previous night and its pilots had noticed nothing unusual, he said.
"We knew of no defects," he said.
The aircraft was fairly modern and of a model in use around the globe.
The plane had embarked on a flight from Durban to Pietermaritzburg, and was to fly to Joburg once it had picked up passengers.
Moments after it took off around 8am, one of the plane's two engines lost power and failed.
The plane was committed to the take-off and, although alerted by air traffic control to smoke pouring out of the engine, had to continue.
But almost immediately, the pilot began scanning for an empty field to make an emergency landing.
He crashed-landed about 400m from the airport.
"In theory, it shouldn't have crashed," an industry source said. "All airliners should be able to fly on one engine. There must have been some kind of catastrophe."
Foster said the pilots on board the Jetstream were "experienced".
Aircraft in the company's fleet were being checked, but all seemed to be in order and no defects had been identified.
Once the Civil Aviation Authority had completed its probe at the crash site, and all the fuel had been pumped out of the tanks, the wreckage would be moved to a hangar for further investigation.
It was hoped the black box recordings would shed light on what caused the crash.
The turboprop Jetstream J41 was the first South African-registered commercial aircraft to have crashed since the SAA Helderberg went down over the Indian Ocean in 1987.
Lindin Birns, spokesman for BAE, which manufactured the aircraft, said only 100 J41s had been manufactured, in Scotland. They had begun going into service in 1993.
The one that crashed yesterday, with the serial number 41069, had been built in 1995.
There were 71 J41s in service around the world, and 15 of them had been in use by SA Airlink.
Birns said that globally, the propeller-driven Jetstream J41s had clocked up a combined 2.73 million flying hours.
They were used mainly in the UK and Australia, and in Africa by SA Airlink, Birns said. He said South Africa had a good commercial aviation record.