Ultimately it was up to the airlines themselves to determine whether potential hazards on their routes were within “an acceptable level of safety”, he said. Locals gather near part of the MH17 wreckage near the settlement of Grabovo. Credit:Reuters Mr Bartsch said there had been instances, such as a volcano eruption in Chile, when Australian airlines had chosen not to fly even though the airspace was declared safe by authorities. “You can use the analogy of a policeman can’t be there to tell you when to cross the road and when not to,” he said. “It is up to the individual, in the case of airlines, to make that assessment.” European air traffic control group Eurocontrol said Ukrainian authorities had closed the airspace from the ground level to 32,000 feet but the airspace at 33,000 feet, where MH17 was flying at the time it was shot down, had remained open.

Malaysia Airlines said the usual flight route was earlier declared safe by the International Civil Aviation Organisation. The International Air Transportation Association has stated that the airspace the aircraft was traversing was not subject to restrictions. However, other airlines had chosen to avoid that airspace. Qantas said none of its flight paths track across the Ukraine and its London to Dubai services flew 400 nautical miles south of the region, having been rerouted several months ago amid the conflict between Russia and Ukraine. Emirates said it had suspended flights from Dubai to Kiev subject to further notice, but added its flights to and from Europe and the US flew a different route outside the zone where MH17 was shot down. Cathay Pacific confirmed its flights did not fly over the concerned airspace. Singapore Airlines would not say whether it had been flying over Ukraine until the incident occurred. “We generally have a number of pre-existing flight paths for our flights to and from the destinations that we are operating to,” a Singapore spokeswoman said. “At this point, we are no longer using Ukrainian airspace and have re-routed all our flights to alternative flight paths that are away from the region."

Mr Bartsch said deciding not to fly over a conflict zone such as Ukraine, Syria, Israel, Libya or Iraq would come at a commercial cost to an airline, because more fuel would be required at a time of high fuel prices. “Obviously with airline operations now, they are increasingly commercially competitive,” he said. “It means that unless they perceive a risk that is sufficient, they are not going to do anything other than the lowest cost route.” “I think the problem is if sometimes every other airline is doing it or the majority of airlines are doing it, airlines are drawn into a false sense of comfort, if you like, to think ‘if it is good enough for them, it is good enough for us’.”