Timeline for Why is airspeed different in climbs and descents although the AoA doesn't change?
Current License: CC BY-SA 4.0
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| Apr 23, 2019 at 5:30 | history | edited | Sanchises | CC BY-SA 4.0 |
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| Apr 22, 2019 at 23:27 | comment | added | Robert DiGiovanni | Little bit of a "eureka" moment realizing the stabilized speeds for climb and dive in this exercise matches the effects of spoilers vs flaps discussed in another question, except the downforce difference is on the tail. Here the trim position of elevator gives more down force in the dive (just like spoilers, makes plane "heavier") resulting in faster speed. This is because of the reduction of the power from 95 to 85% (the thrust providing nose up force from "underslung" engine) requires more tail down force trim to maintain same AOA. Climbing, with more power, tail down trim is less. | |
| Apr 22, 2019 at 18:25 | comment | added | Sanchises | @MikeY You make a good point. I suppose the main factor must then be the tailplane lift. Thanks for the correction. | |
| Apr 22, 2019 at 13:09 | comment | added | MikeY | I agree that in a steep climb the thrust would carry more weight and so IAS could be lower for the same AOA, but that property should also hold for a dive, where the drag is now carrying some of the weight. The extreme is an non-accelerating almost vertical climb or dive. For both conditions, you'd have to be at a very low airspeed to see 15 units AOA. | |
| Apr 22, 2019 at 11:49 | history | edited | Sanchises | CC BY-SA 4.0 |
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| Apr 22, 2019 at 11:39 | history | answered | Sanchises | CC BY-SA 4.0 |