[1] On the day of the accident, Iranian air traffic controllers went on strike, which led to hundreds of domestic flights being cancelled.

[2] At 18:52 local time, the controller at Mehrabad airport in Tehran gave the crew a direct approach to runway 29.

At 19:11 local time, the aircraft collided with the Alborz Mountains, 29 kilometres (18 mi; 16 nmi) north of Tehran.

[3] Investigators concluded that the probable cause of the crash was believed to be an inoperable instrument landing system and ground radar.

The head of Iran's Civil Aviation Authority and five other officials were charged with manslaughter as a result of the crash of Flight 291.