flight path calculation formula help

coindex765 · Feb 6, 2019

I have been trying to research and gain knowledge of flight data calculations regarding flight path data to elevation data and landing data for crash analysis. What I am trying to gain knowledge on is finding my flight path and possible "crash sites" on lost connection issues if this ever happens to me (knock on wood)

In my findings I have found that the data needed is altitude/elevation, speed, wind direction and speed, and speed/rate of descent. Now the tricky part is to find out the equation to solve said possible crash site
so say in this scenario I was flying at 300m level flight Northbound at a speed of 20km/hr. Wind direction is southbound (so I took off into the wind) at 15knots (17mph). At 150m from home point connection lost from RC -- battery level 70%. No regain of connection. Find approximate location from home point of crash site/touchdown site.
Do I just use trigonometry with my given co ordinates and this information? If so, what would be the formula for calculation?

Maxx Levell · Feb 6, 2019

Google trajectory, or ballistic formulas...should give you what you're wanting.

coindex765 · Feb 6, 2019

Maxx Levell said:
Google trajectory, or ballistic formulas...should give you what you're wanting.

alright thanks, I'll look into those

JDawg · Feb 6, 2019

@sar104 @Meta4

sar104 · Feb 6, 2019

JDawg said:
@sar104 @Meta4

There is no analytic formula for this because there are too many variables to construct a suitable single function to the location problem. You can use the approach that I take, which is to fit individual linear regression functions to the battery depletion rate, the smart RTH battery level, and the wind-induced drift (if present) but then you really have to solve the resulting problem by inspection. Anyone who follows these kinds of questions will have seen the graphical solution method that I use.

It's not a ballistic problem except for the specific case where the aircraft shuts down in flight - then it's just a coupled gravity/drag/airspeed problem. There are analytic solutions to that but it is far better solved numerically.