Three crew members have died after a military plane crashed during a test flight near Moscow on August 17.
Russia's United Aircraft-Building Corporation (OAK) said the only operational prototype of the IL-112V military cargo plane crashed near the town of Nikolskoye, killing three crew members aboard.
OAK also said that the plane most likely crashed after one of its engines caught fire.
A video taken by a witness of the crash shows flames on the right side of the plane as it approaches an airfield. It then loses control and crashes into a wooded area.
Investigative Committee spokeswoman Yelena Markovskaya said investigators had been sent to the site to probe the accident.
The Il-112V is the first military transport aircraft to have been developed "from scratch" in Russia in the post-Soviet period.
Its development began in the early 1990s and faced constant difficulties due to a lack of funding.
The plane was expected to be shown at the international military and technical forum Army 2021 in the Moscow region. The forum runs from August 22 to August 28.