The Russian air force has resumed flights of its Tupolev Tu-160 swing-wing supersonic strategic bombers following completion of the investigation into a crash near the village of Sovyetskaya, 40km (25 miles) off Engels air force base in central Russia on 18 September. The Tu-160s resumed flying on 5 November from Engels. The Tu-160 crashed unarmed on a test flight after the No 4 Kuznetsov NK-32 engine had been replaced.

The crew had completed engine tests and were descending to Engels when the commander reported a "fire in engine No 2". Seconds later the aircraft, flying at 3,900ft (1,200m), exploded in mid-air. All four crewmembers were killed.

The explosion broke the bomber's titanium centrewing box, leading to suspicions of a terrorist act.

Russian air force commander Gen Vladimir Mikhailov says a technical failure caused the crash. "The commander and crew acted professionally to the very last second of flight," he says.

The 18 September crash was the first since the Tu-160 became operational 17 years ago. The Tu-160 fleet is undergoing a mid-life upgrade, receiving improved Raduga Kh-55, Kh-555 and Kh-101 cruise missiles and other guided weapons.

Source: Flight International