Photo from UNIAN

The investigation is looking into four versions of what has caused the recent crash of a Su-27 flanker jet in Ukraine's Vinnytsia region, among them the human factor, technical malfunction, poor fuel, and weather conditions, that's according to Anatoly Matios, a top military prosecutor.

“Four main versions are being worked out: the human factor midflight, technical malfunction of the aircraft, possible fueling of the aircraft with poor-quality fuel, or weather conditions that led to the catastrophe,” Matios told 112 TV channel.

According to the chief military prosecutor, in July, the aircraft underwent a major overhaul along with full modernization.

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Matios noted that from the moment of the repair, the aircraft saw only 20 flight hours, while its life service was extended for another 12 years.

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“We have interrogated multiple witnesses,” he added, noting that the crash scene had been thoroughly inspected.

“We collected human remains, scattered almost a kilometer across the area. The plane nosed down almost 1.5 meters deep into the ground,” he noted.

The information is now being recovered from a flight recorder, the official said.

As UNIAN reported earlier, on October 16, at about 17:00, a Su-27 military jet crashed near the village of Ulanov, Vinnytsia region, between settlements of Berdychiv and Khmilnyk.

Both pilots – a Ukrainian Air Force pilot, and an officer of the U.S. National Guard - were killed in the crash.