"Recovery groups went to the site of the plane crash and found the wreckage, and the body of the deceased pilot," the official said.
The plane's black box has also been found.
Lieutenant Colonel Andrei Vakhovsky, born in 1962, crashed near the town of Bryansk on the border with Ukraine on Wednesday morning.
"At 9.55 a.m. Moscow time [5.55 a.m. GMT] flight leader Andrei Vakhovsky asked for permission to descend because he was feeling unwell and began descending," Air Force spokesman Drobyshevsky said Wednesday. "At 4,200 meters [13,800 feet] he once again informed his wingman that he did not feel well and continued descending... The wingman repeatedly told him to eject, but the flight leader did not react."
Drobyshevsky added that the plane with Vakhovsky hit the ground at 10.18 a.m.
The most recent crash involving a Su-25 plane occurred on May 21, 2005 in Tajikistan. The pilot managed to eject from the plane and an investigation later established that the accident had been caused by technical problems.
Survivability was one of the main design criteria when the aircraft was developed by the Sukhoi design bureau. The pilot is encased in an all welded titanium-enforced cockpit, while the widely separated engines are armored with stainless steel bays. The fuels tanks are also armored and filled with foam to prevent explosion.
