Russian pilot given mixed instructions seconds before impact, say investigators

The Russian pilot involved in last week's mid-air crash which killed 71 people was given conflicting orders by Swiss air traffic control and his automatic warning system, the German investigation team revealed yesterday.

Ground staff told the crew of the airliner to dive to avoid an oncoming cargo plane, but the TCAS on-board crash-avoidance device ordered the plane to climb.

The pilot of the Tupolev 154 airliner, Alexander Gross, obeyed the second command from controllers to descend and 30 seconds later crashed into the Boeing 757 freight jet.

Voice recorders recovered from fragments of the two planes scattered across the Swiss-German border showed that the on-board system on the Boeing had told its pilot to dive. The systems are designed to communicate so that the aircraft are sent in opposite directions to avoid a collision.

The recordings showed that the on-board warnings were delivered simultaneously on each aircraft. A second later the Russian plane lost height.

If the Russian pilot had obeyed the synthetic voice on his aircraft telling him to climb, rather than the air traffic controller, the disaster might have been avoided.

In the West, flight crew are instructed to obey the on-board computer if its directions conflict with advice from the ground staff – although it was not clear yesterday if those were the standing orders for pilots with all airlines.

The voice recordings confirm that Swiss air traffic control told the Russian pilot to descend twice, the second order 14 seconds after the first. Thirty seconds after the second command, which the Russian pilot obeyed, the planes collided at 35,000 feet.

Earlier yesterday German air traffic controllers, who had handled the Russian plane on its way from Moscow, said they tried to warn the Swiss control centre by telephone two minutes before the impact.

German controllers had received a signal from ground-based equipment that the planes were on collision course. It has already been established that a similar device at Swiss centre was not in operation at the time because it was undergoing maintenance.

Prosecutors are deciding whether anyone involved can be charged with negligent homicide.

German investigators found last week that the telephone system at the Zurich control centre was also being worked on at the time of the crash and the single controller on duty was working on a reserve line.

All 69 people on board the Russian aircraft, including 45 students heading for a Spanish beach holiday, and the pilots of the cargo plane – one of them British – were killed.