WE extend our sympathies to the families of the four pilots — two instructors and two trainees — killed on Thursday when two Pakistan Air Force aircraft collided in mid-air over Nowshera district. These were lives lost in vain, and while a board of inquiry has been ordered by the air headquarters, it might not be possible to ascertain the true cause of the accident. There is reason to be thankful, though, that the mayhem caused on the ground wasn’t worse. Eight civilians were injured, four of them seriously, when the wreckage of the aircraft fell on two houses in the Rashakai area, badly damaging both structures. The tragedy should be taken, though, as a reason to revisit the issue of the route taken on flight training sessions and the harm that can come to people on the ground in case accidents occur. This is the second plane crash involving trainee pilots this year where the wreckage fell on houses with civilians in them. In February, a small aircraft that had taken off from Lahore’s Walton Airport crashed in the Model Town residential area; both the instructor and the trainee were killed in that instance too. Accidents can of course happen anywhere, at any time, but the risk is arguably greater when trainees are involved. City administrations, in conjunction with military authorities and airport managers, therefore need to look into how best to protect populations on the ground. True, this is no doubt a challenging task, given that apart from the urban centres small towns and villages dot much of the country’s landscape liberally. But at least an effort can be made to ensure that as few flight paths as possible go over densely populated areas. While the risk factor can never be removed entirely, especially where air traffic is concerned, steps can be taken to mitigate it.