Distance above moving objects

ChuckD · Jan 12, 2016

Realizing that in normal circumstances we shouldn't be flying 'over' too many things, I was wondering what would be adequate distance above a vehicle to avoid any ground turbulence.

For example, let's say a train was passing underneath at 40 mph. Obviously I don't want to be immediately above it, since it would surely knock me out of the sky. How far above should I be to be 'safe'? I know the larger and faster the vehicle, the more height I would want. But any rule of thumb?

I'm sure we've all seen that racing video where the car zips underneath a Phantom and sucks it right out of the sky. I'd hate for that to happen!

Ray Stachelek · Jan 12, 2016

To me, it's a question of good judgment in my mind.
Would I purposely put my drone close over a moving train.
Probably not. I'm more afraid, if I crashed the thing on it, they would know who to blame, probably have some agency come down hard on me. Would I stay off the track, (pun intended), yes! It would make such a unique moment to capture.

I wouldn't fly my drone either over major bridges that have major traffic routes even though it would make for great photography.
What happens is a motorist panics or gets distracted seeing this thing flying overhead. As you know, FCC has acceptable guide lines where not to fly.

To answer you question on acceptable distance, use a tandem tractor trailer on the highway passing you as an example. How many lanes away to you have to be without feeling the effects of wind disturbance.

Rick Dunn · Jan 15, 2016

ChuckD said:
Realizing that in normal circumstances we shouldn't be flying 'over' too many things, I was wondering what would be adequate distance above a vehicle to avoid any ground turbulence.

For example, let's say a train was passing underneath at 40 mph. Obviously I don't want to be immediately above it, since it would surely knock me out of the sky. How far above should I be to be 'safe'? I know the larger and faster the vehicle, the more height I would want. But any rule of thumb?

I'm sure we've all seen that racing video where the car zips underneath a Phantom and sucks it right out of the sky. I'd hate for that to happen!

Hi Chuck,

Thank you for asking the question instead of just doing. I am not wishing to pile on you; however this really should not even be a question. To directly answer your question flying above any vehicle as a non-commercial hobbyist without permits, direct permission and safety measures in place is unacceptable. All of the heat this segment of the r/c community has received has been derived from people doing things that are unsafe and unwise.

Please do us ALL a favor (including yourself) and do not fly above people, vehicles, near airports (5 mile radius), over roads, highways, interstates and so on. R/C flying is a PRIVILEGE not a RIGHT and if it continues to be abused, that privilege will be taken away whether you think it can and will or not!

ChuckD · Jan 15, 2016

I'm really thinking for my own purposes, and not for flying over public transportation.... I just used a train as an example because here in my office there's a railroad track nearby and a train was going through, so it got me thinking.

I'm sure other people get contracted to shoot moving objects (with permission). I just didn't want this to happen (about 1:52 into this video, I'm sure most people have seen it).