Last call for the flight simulation test?

‘‘Dear Colleague, Please see and advise on this patient with COPD who wishes to fly’’. This is a common request from our non-respiratory colleagues and although we have guidelines to follow to assist in answering their queries, the evidence on which the guidelines are based is weak. The most recently published air travel recommendations are those from the British Thoracic Society (BTS) [1], which try to make some sense of the evidence and provide guidance based on expert consensus, but the recommendations for prescribing oxygen during a flight remain, at best, level C.