jpatokal
10th Jan 2009, 14:35
Sorry if this is a really basic question, but googling for this info pulls up a lot of apparently contradictory info and I'm not really competent to judge if the answers I got are sensible, so I wanted to check with the experts.
So. I've built a little open-source app (http://openflights.org) that maps flights, and I'm currently designing a module that exports your flight data into 3D paths that can be plotted with Google Earth etc. This means that I need to be able to at least crudely simulate a typical flight profile of a commercial airliner (let's say 737) for takeoff and touchdown.
What I've figured out so far:
* Takeoff speed for commercial airliners is 150-180 mph.
* Average ascent speed is around 2500 ft/min, but faster in the beginning and tapering off near cruise altitude. This (http://altairva-fs.com/fleet/poh/Boeing%20747%20POH.htm) (747) suggests 2200fpm from 10,000 - 20,000ft @ 280 - 340kts, 2000 - 1500fpm from 20,000 - 26,000ft and 1500 - 400fpm from 26,000 - 35,000 ft depending on weight. (I'd love an equation for this!)
* Cruising speed for a 737 is 476 knots/547 mph.
* Cruising altitude for long-distance flights is typically 30,000 ft.
* Descent starts around 100 nm from destination.
* Average descent speed is 1500 ft/min, but faster in the beginning and tapering off near landing. 747 page above suggests 2500 ft until 10,000 ft, then 800-3000 fpm until slowing down to 200-400 fpm from runway threshold to touchdown. (Again, an equation would be lovely.)
* Speed at touchdown should be ~20% less than takeoff, so 120-150 mph.
Am I on the right track with these figures? I know that in real life, these all depend on a million factors, but this is just for a simple, generic simulation without weather, wind, ATC etc etc. Any tips much appreciated :uhoh:
So. I've built a little open-source app (http://openflights.org) that maps flights, and I'm currently designing a module that exports your flight data into 3D paths that can be plotted with Google Earth etc. This means that I need to be able to at least crudely simulate a typical flight profile of a commercial airliner (let's say 737) for takeoff and touchdown.
What I've figured out so far:
* Takeoff speed for commercial airliners is 150-180 mph.
* Average ascent speed is around 2500 ft/min, but faster in the beginning and tapering off near cruise altitude. This (http://altairva-fs.com/fleet/poh/Boeing%20747%20POH.htm) (747) suggests 2200fpm from 10,000 - 20,000ft @ 280 - 340kts, 2000 - 1500fpm from 20,000 - 26,000ft and 1500 - 400fpm from 26,000 - 35,000 ft depending on weight. (I'd love an equation for this!)
* Cruising speed for a 737 is 476 knots/547 mph.
* Cruising altitude for long-distance flights is typically 30,000 ft.
* Descent starts around 100 nm from destination.
* Average descent speed is 1500 ft/min, but faster in the beginning and tapering off near landing. 747 page above suggests 2500 ft until 10,000 ft, then 800-3000 fpm until slowing down to 200-400 fpm from runway threshold to touchdown. (Again, an equation would be lovely.)
* Speed at touchdown should be ~20% less than takeoff, so 120-150 mph.
Am I on the right track with these figures? I know that in real life, these all depend on a million factors, but this is just for a simple, generic simulation without weather, wind, ATC etc etc. Any tips much appreciated :uhoh: