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Calculating VDP

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Calculating VDP was the original question...not calculating PDP (planned Descent point). If there is a VDP you will not need to calculate anything...it's published on the profile view of the non precision approach with a V symbol. There will be a DME amount beside the V so you will know when to descend. As far as what rate to descend, 95% of the time the VDP will coincide with a PAPI or VASI..so for 95% of the time nothing to calculate. For the other 5% of the time when there is not a visual glide path simply take half your ground speed and add a zero to detemine your vertical descent speed. (120 knots GS... 1/2 of 120 = 60...add a zero to 60 to get 600 feet per minute on your VSI). The previous answers were all correct for PDP which is the point on an approach where a pilot must begin the descent to the runway... but that point is not published like a VDP.
Hope that helps.
 
It's actually a PDP not a VDP

DISTANCE:

HAT / 300 = VDP (miles)

ex. HAT = 600'/300 = 2 miles.
VDP is 2 miles prior to MAP




TIME:
10% of HAT = VDP (time)

ex. HAT = 600' x .10 = 60 seconds.
VDP is 60 seconds less than the published time for category.
 
who cares? fly an FMS airplane with vnav capabilities, so you shoot rnav, gps , vor or ILS , all of wich have vertical guidance.

Unless of course the MAP is at the VOR which is a mile from the threshold and there is no Gradient Path. Then it's back to V/S and a VDP. :beer:
 
Gs
------ = Vdp
Hat
 
1.3 miles from the end of the runway, works fer just about all of them.

Try it you'll see.
 

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