Kazakhstan's military authorities have grounded all the nation's MiG fighter jets following a crash earlier this week that killed the pilot and injured the navigator of a MiG-31 interceptor, Kazakhstan’s air force chief said on Thursday, April 25, RIA Novosti reported.

The Kazakhstan Air Force Mikoyan MiG-31 interceptor crashed during a training flight in central Kazakhstan on Wednesday. The crew managed to eject from the plane before the crash, but the pilot died. A probe was opened into the accident.

“We’ve halted MiG flights until the cause of crash is cleared up,” Kazakhstan's Air Defense Forces chief Lt. Gen. Alexander Sorokin said.

The air force said immediately after the crash that a technical problem was the likely cause of the incident.

In a statement on Thursday, it said the aircraft had been flying at 3,000 meters altitude (10,000 feet) when it suddenly entered an undemanded roll to the left and entered a steep spiral dive. The pilot tried to recover the aircraft but could not, and as the machine passed 1000 meters altitude the crew ejected, with the navigator leaving the aircraft just before the pilot.

The aircraft was diving very rapidly as the crew ejected and the pilot's parachute did not have time to fully deploy, the air force said on its website.

The Kazakh Defense Ministry said the aircraft which went down underwent a major overhaul at a Russian factory in December. The MiG-31 was performing its fifth flight that day, and had flown 42 hours since its overhaul.

The world's fastest military aircraft in service, the MiG-31 is designed to intercept enemy aircraft at long distances with a powerful radar and weapons system. It is operated only by Kazakhstan and Russia.