At present the total number of military and civil flights across the North Atlantic is about 130 per day counting both directions. Once aircraft are outside the systems of airways used in the high traffic density areas over each continent there are no fixed traffic lanes and aircraft plan their flights independently, generally following composite tracks to take maximum advantage of the wind distribution. Pilots are familiar with the natural tendency for tracks to diverge even when aircraft are being navigated via the same route but when the navigator in each aircraft is following an independent flight plan the separation of tracks will be much greater. Thus on the 2000-mile North Atlantic route the traffic density in real terms—say the number of aircraft per 10,000 square miles—is extremely low, and it is open to question whether the chance of two aircraft colliding in mid-Atlantic is not so remote as to be treated as an impossibility for practical purposes. This may sound heretical but if, as the writer suspects, the chance is so low as to make no significant difference to the overall risk of aircraft accidents, then there are other aspects of aircraft operation where the attention now being given to Atlantic traffic control might yield quicker dividends in the improvement of air safety.