What happened
On 16 April, an aircraft departed Mehrabad Airport at 0228Z for a charter mission serving Yazd and Bandar Abbas. Following the initial leg of the journey, the flight proceeded to Shiraz for an overnight stay. The following morning, EP-ABA, a charter aircraft, departed Shiraz at 0245Z to collect four passengers from Marvdasht.
The flight departed Marvdasht at 0525Z, with a scheduled arrival at Mehrabad Airport in Tehran for 0800Z. At 0630Z, the crew established contact with Esfahan, reporting their position approximately 20 miles east of the station while flying under VFR at flight level 150. This communication served as the final transmission from the aircraft.
On 19 April, reports reached Mehrabad Airport indicating that the aircraft had crashed into a mountain located 40 km south of Ardestan and 18 km west of Zafarkand Village. The impact resulted in five fatalities, including the pilot and all four passengers, and led to the total destruction of the airframe.
Findings
The investigation determined that the pilot encountered sudden and severe carburetor icing. This-led to a loss of engine power, which forced the pilot to descend through a cloud layer where icing conditions likely worsened, preventing the ice from melting. The situation became critical as the aircraft entered clouds over mountainous terrain with poor visibility.
In an attempt to navigate around mountain barriers, the pilot tried to maneuver through a narrow gorge and a visible gap at the summit. However, due to persistent engine power loss caused by icing, combined with heavy turbulence and downdrafts near the crest, the aircraft could not clear the terrain. The flight path ultimately resulted in a collision with a protruding rock formation.