Return alternate single engine distance.
Assuming you have an engine failure and cannot get back into your departure aerodrome (say it is below cat 1 minima) how should the distance be worked out.
Our SOPs say within one hour single engine but does not advise on a distance. Some trainers use the 400NM figure used for 737 NG ETOPS.
If you have an engine failure in the cruise I am not convinced you could average 400 knots with your potential energy...that aside here are my totally unscientific ballpark figures.
20 mins in the climb at 220 knots...10 mins on approach averaging 200 knots and a max single engine speed for 30 mins of cruise of less than 400 knots = closer to 300 miles.
I assume there has to be some guidance (or at least some better empirical data than above) somewhere.
Any help much appreciated.