# Top of climb, Top of decent

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Hi guys, any ideas as to how ( in XML ) I can work out the distance and time to the TOC and TOD in an FSGPS style FMC CDU :)

regardsEd

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I don't know if you could do it using a 3 degree descent profile, but I am sure that a FPM descent profile would work. You would just have to work the math concerning the groundspeed, altitude and desired descent rate. Ground speed would translate to ETA to the given way point. As a rather generic example, traveling at FL200, you want to have a descent rate at 2000FPM, and the destianation is at sea level, it would take appx 10 minutes to descend that 20,000 ft and arrive at the airfield elevation. So 10 minutes time to waypoint would be the top of descent. Groundspeed would have to be worked in to figure out actual distance. That is how I would do it anyway. Primitive, but it should work.

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I also forgot to add: a 3 degree glide path is I belive 318 feet over one nautical mile. This could also help with the calculations. Current altitude divided by 318 = Distance to waypoint for top of descent figure. providing a deviation indicator is a whole 'nother ball game though. Hope this all helps. Let me know or drop me an email, I would like to chat with you about a few things. Send mail to IGrant@wi.rr.com

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