View Full Version : Turn Radius Formula & Ascending/Descending Turns
Badmachine
3rd Oct 2010, 23:26
When calculating the turn radius for an ascending or descending turn, does the gravitional constant value need to be adjusted accordingly?
Could the standard turn radius formula apply to ascending or descending turns and generate correct results?
In practical terms, no. The other variations in performance, human, computer and nature far exceed the small variations due to what are normally small descent/
climb angles.
Why in particular the question? Are we theoretical or practical?
CabinMaster
4th Oct 2010, 09:43
You want to calculate turn radius?
That is a pure function of turn acceleration and level flight speed (true). It is the acceleration you actually put in the turn.
It is no problem to separate vertical from lateral motion.
compressor stall
4th Oct 2010, 10:20
Why stop there? What about the relativity issues?
Piltdown Man
4th Oct 2010, 10:53
Probably yes, but a close enough formula is TAS (Metres/Second) Squared/(Tangent of Angle of Bank * g). For g I'd use 1.
PM
CabinMaster
4th Oct 2010, 11:26
g still is approximately 9.81 m/sē.
Maybe gravity in Piltdown is much less? Is it on the moon?
hetfield
4th Oct 2010, 12:53
Maybe gravity in Piltdown is much less? Is it on the moon?Must be somewhere else, on the moon it's 1.63 m/sē.
Now - this is a matter of some gravity. A weighty problem indeed.
CabinMaster
4th Oct 2010, 15:56
Or he uses a different unit.
The answer is always "42".
Just the unit changes.
Rivet gun
4th Oct 2010, 16:35
A very good point. I suspect he is using the TGM unit system, which is best for people with 12 fingers :)
TGM - a coherent dozenal metrology (http://www.fergusoncreations.co.uk/home/shaun/metrology/tgm.htm)
Pugilistic Animus
6th Oct 2010, 00:57
no...the circumferential velocity vector, and the vertical velocity vector are kinematically independent; they are mutually exclusive axes:)
shafqatgreat
16th Jan 2017, 05:18
How to calculate a turn radius while aircraft is continuously descending(with some dive angle) and turning with specific bank angle.
RAT 5
17th Jan 2017, 10:51
Don't forget to factor in the rotation of the earth as you descend, and the change in pressure. :rolleyes:
Broomstick Flier
17th Jan 2017, 12:53
I was about to mention Coriolis effect, but small cog beat me on that...