most manufacturers would argue that stability for a safe approach is required earlier in the approach in order to get the aircraft near Vat and 50 ft at the threshold
- most companies too. I am sure this is the point of a 'stabilised' approach. In BA, the last 'decision' gate is 500ft AT, with the proviso that Vref+15 is the 'limit' at touchdown for 'limiting' runways. I have used Vref+25 into LGW R26 in conditions of high windshear (long live 'Sir Freddie'!) with no problems. I tend to 'bleed' the excess as I see the conditions. Once I have a landing surface below me I am somewhat more relaxed
The auto/manual argument is an interesting one: I have NEVER had an answer from the 'knowledgeable' (ie trainers!):
Boac is barrelling down the approach, auto-throttle engaged, runway wind +20 gusting 10-30. Boac would like Vref + 30 (incidentally, I believe half the wind plus all the gusts is an OLD aviation rule, not a 'Boeing'?). Being a good lad, he bugs Vref+5 as per Boeing, thinking Vref+15 would be acceptable if runway is limiting. The A/T makes valiant (if uncomfortable!) effort at controlling at a safe speed. At some height he bravely disconnects the A/T
since leaving Boeing's A/T engaged TOO long would be exciting!
Dilemma! He is supposed (and trained) to fly 'bug' speed. Does he re-bug to Vref+15 or should he have selected Vref+15 with A/T?