Investigators in Iran are considering whether high landing speed contributed to yesterday's fatal Ilyushin Il-62M accident in Mashhad.
Flight recorders from the Aria Air aircraft have been retrieved, according to the Mashhad Airport operating agency. The Il-62 had been operating a service from Tehran.
Iranian Civil Aviation Organisation suggests the aircraft was travelling at high speed during the landing - unconfirmed reports claim 200kt - but adds that the reason remains unclear.
The aircraft apparently overran the runway by about 1km (3,300ft), striking a wall and coming to rest in rough scrubland, close to agricultural terrain.
About 40ft of its forward fuselage - including the cockpit and several rows of the passenger cabin - was completely destroyed. Surrounding debris includes several passenger seats.
The remainder of the airframe stayed largely intact. Images of the wreckage show the landing-gear and flaps deployed, as well as partial deployment of the thrust reversers on the outer pair of engines.
The Il-62's inboard starboard flaps are detached and the leading edge of the left wing appears to show impact damage along its length.
Kazakh carrier Deta Air confirms that it leased the aircraft to Aria Air for a two-year period which was due to expire in December 2010.
Deta says the aircraft was leased in a condition compliant with ICAO requirements.
It says that "all the crew members" on board the aircraft were killed. Sixteen fatalities in total have been reported, three of them passengers, with the managing director of Aria Air among the victims.
Iranian authorities have reportedly suspended the operating permit of Aria Air while the inquiry proceeds.