Originally Posted by
FlightDetent
Mine:-
(1) -> 26x 3 = 7500 (approx) + 6000 G/S intercept =>> 3 deg profile is 13500'
(2) -> the A/C is 1500' above
(3) -> 370 /20 = 1900 fpm is required to keep a 3 deg descent
(4) -> with present sink of 2200 we're slowly regaining the profile from above.
This arithmetic gives a good understanding of
- where you are (2)
- where you will be (4) based on GS, the effect of wind is already accounted for.
Obviously, with deceleration towards 250 knots coming soon that nice, steeper-than-3° trajectory won't last for long.
Personally, I do not make any mental calculation adjustments for the decel segments (250 / 210). I just run the (2) and (4) again and again, as many times as required. Anticipation notwithstanding!
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The above example is quite critical, me thinks.
- With platform at 3000' and 270, it would be "rather efficient"
- With platform at 3000' and 290, I'd say daring,
- With platform at 6000 and 270, it looks borderline,
But 6000 and 290, with 1500 above already? The (vertical) room to slow down, which needs to be done soon to 250 and then almost immediately to 210ish, is just not there.
Choice of weapons depends. My present operator requires 250 below 10k AFE, so A/P off and full speed-brake for us
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Really interesting, thank you Flight Detent for your wonderful contribution.
I agree with you regarding 6000’/290kt with the restriction of 250 below FL100AFE is definitely tight, without is achievable, probably with a bit of S/brake.
I’ve always used an arithmetic approach in flying. Some colleagues think I’m overcomplicating but I like to run 3x rule as much as possible especially getting closer.
I used to make an allowance for deceleration from 250/210 and I found pretty useful especially in some places where due to traffic/ATC I was left higher than platform. Eg with FAP 3000/9nm and stuck at 5000’ I knew that I could keep 210kt no more than closer than 18Nm then maybe better going managed and select F1. I found this arithmetic approach always reliable and a huge help maintaining awareness.
Definitely next flight I’ll try your tips as I think are definitely better and easier