Superb! The system works. PPRuNe at it's best. Many thanks for that feed back.
I was very aware that life for you all on the ground was very buisy, and seemed to me at the time, very fluid. The French addition is very interesting. (As was the AF that decided to leave the hold unannounced). I tried a couple of times to communicate ASAP my conundrum. I think I managed to block a few transmissions on the way. But it all got sorted, and no one seemed to get frightened.
We were handed over to you at FL 400. Above the optimum level, but Reimes pushed us up. Min clean at that level is sporting, but OK for a while. If you then need the speedbrakes, as you know, they are effectively barn doors on the wing. So the stall speed goes up. If you are back at min clean, then the stall speed at that level rushes up to meet you. The 747 has a very swept, old school wing. Absolutely superb at M.86. But get the speed back, get behind the drag curve, and it is not a happy aeroplane. Min clean yesterday, below FL200, with a full load, and "normal" fuel load was 235kts. That is fast.
Here is a picture of what I see in "coffin corner". I show it so you can see the speed tape.
C-Corner
In this picture the onset of low speed buffet is 258kts. (Top of the bottom yellow tape). So if now pull the speedbrakes out, that yellow "hockey stick" moves up. If the speed had been at min clean, then the yellow tape would have covered my indicated speed, telling me that my speed is too low. The top of the red and black barber pole, bottom left, is the stall speed. The top of the yellow tape is the 1.3G buffet margin that the CAA ask of us. Curiously if the aeroplane had been on the USA register, It would have a 1.2G margin, and have more room to maneuver.
Brains immeasurably greater than mine I am sure will correct me if I am wrong, but the above is roughly what happens!
Maybe its yet another call to get ATCO's back in the cockpit more so we can broaden our knowledge, I wouldn't mind seeing what Mauritius looks like this time of year when the rain is tumbling down on the centre......
Amen to that. As things get more and more congested, and we are all trying to operate as efficiently as possible, good communications can only help us all. And Mauritius is nice this time of year also.
