Iran has published the first preliminary report on the crash of the presidential helicopter:

Iran has published the first preliminary report on the crash of the presidential helicopter: The helicopter flew along a given flight path and remained there a minute and a half before the crash. The pilot of the injured helicopter contacted two other helicopters of the flight group. No impact from bullets or similar objects was observed in the components of the crashed helicopter. The crashed helicopter caught fire after hitting the mountainside. Due to the complexity of the terrain, fog and low temperature, the reconnaissance operation was extended overnight and continued all night, and on Monday morning (at 5 am) with the help of Iranian UAVs, the exact location of the crash was found. No suspicious cases were recorded in conversations between the flight control center and the flight crew. Much of the paperwork related to the said helicopter crash has been collected and more time is needed to examine some parts and documents. Source: Lord Of War