Iran Aseman Airlines flight 3704 crashed in the mountainous area north of its destination of Yasuj. According to our data the flight departed Tehran about 04:33 UTC (08:03L). The flight was due to land in Yasuj at 09:50 local time. Flight 3704 was operated by ATR 72-212 EP-ATS (MSN 391), first delivered in 1993.
EP-ATS was equipped with an older Mode S transponder. Flightradar24 tracked EP-ATS with Multilateration (MLAT), using the time difference of arrival of radio signals from the aircraft to determine position. In order to determine the position of the aircraft, signals must be received by four receivers in the Flightradar24 network. When the signals do not reach four receivers, some data, including altitude is still generally received.
The file available for download below includes intermittent position information as well as altitude data as received by the Flightradar24 network.