This past weekend at a beach in Carlsbad, CA. San Diego beaches are notorious for low flying small aircraft. Late last year there was an investigation over a plane that was spotted flying around 20ft from the surface over a group of surfers. Beware!

Wow. You weren't kidding. How high over the surfers were you? I tried filming some, but I was too high. I wasn't sure if they were cool with me filming so I didn't want to get to close.

great footage....I like the slow motion effects...

marvzz Posted at 2017-2-22 07:36
Wow. You weren't kidding. How high over the surfers were you? I tried filming some, but I was too high. I wasn't sure if they were cool with me filming so I didn't want to get to close.

Ill post the raw clip later that better shows just how low i was flying when that plane buzzed by. At that time i was standing on the cliff-side and the plane was almost at eye level.  Some of these shots I had to look at the drone rather than the ipad, in order to make sure there was just enough sky between the drone and the waves.

Jasonstarbird Posted at 2017-2-22 09:01
great footage....I like the slow motion effects...

Thanks! slow motion makes everything so much cooler

Same issue in Pensacola Florida.... Coast Guard Choppers fly low at times....If I am flying in a legal zone, who is at fault?

The plane is allowed down to 500ft, you are allowed up to 400ft.  

Is 100ft separation considered sufficient or should that be reported as a near miss?

The Dax Posted at 2017-2-22 10:55
Same issue in Pensacola Florida.... Coast Guard Choppers fly low at times....If I am flying in a legal zone, who is at fault?

Helicopters are not limited to the 500ft floor.

Fixed wing aircraft are only limited to the 500ft floor in populated areas or where there are built structures.

UAS are always at fault if a collision occurs with a manned aircraft, one major tenet of the UAS world is that we must yield/give way/avoid manned aircraft and manned aircraft operations.

QiiFlight Posted at 2017-2-22 11:32
Fixed wing aircraft are only limited to the 500ft floor in populated areas or where there are built structures.

They are not allowed within 500ft of people anywhere so if you are on the ground and your drone is 400ft above you they can't come within 100ft of your drone.  Presumably if they want to fly lower than 500ft in a sparsely populated area they need to do a flypast to check for people first and that would give you time to get out of the way...

Nigel_ Posted at 2017-2-22 11:51
They are not allowed within 500ft of people anywhere so if you are on the ground and your drone is 400ft above you they can't come within 100ft of your drone.  Presumably if they want to fly lower than 500ft in a sparsely populated area they need to do a flypast to check for people first and that would give you time to get out of the way...

Even if the manned aircraft is breaking the rules, the sUAS pilot (in the US) is still required to give way to the manned aircraft. This is discussed in part 333 section 336 (Hobbyist sUAS operation) and Part 107 (commercial sUAS operation), referenced below.

Hobbyists - Part 333 section 336
Commercial - Part 107 Summary bullet 6

Obviously if it meant my UAS would cause an accident, I would kill it in the air...was just curious....

It's a common misconception that real planes must stay above 500 ft and there and many instances where they can legally fly much lower.
Here are the US FAA rules on the matter.
Note C & D
§ 91.119 Minimum safe altitudes: General.
Except when necessary for takeoff or landing, no person may operate an aircraft below the following altitudes:
(a) Anywhere. An altitude allowing, if a power unit fails, an emergency landing without undue hazard to persons or property on the surface.
(b) Over congested areas. Over any congested area of a city, town, or settlement, or over any open air assembly of persons, an altitude of 1,000 feet above the highest obstacle within a horizontal radius of 2,000 feet of the aircraft.
(c) Over other than congested areas. An altitude of 500 feet above the surface, except over open water or sparsely populated areas. In those cases, the aircraft may not be operated closer than 500 feet to any person, vessel, vehicle, or structure.
(d) Helicopters, powered parachutes, and weight-shift-control aircraft. If the operation is conducted without hazard to persons or property on the surface—
(1) A helicopter may be operated at less than the minimums prescribed in paragraph (b) or (c) of this section, provided each person operating the helicopter complies with any routes or altitudes specifically prescribed for helicopters by the FAA

The Dax Posted at 2017-2-22 14:36
Obviously if it meant my UAS would cause an accident, I would kill it in the air...was just curious....

If you kill it in the air it doesn't instantly disappear out of the way, in fact it can move well over 2x faster under power than it can with the motors off, but not downwards.  By killing the motors it does however become an uncontrolled hazard to anyone on the ground beneath.

The Dax Posted at 2017-2-22 10:55
Same issue in Pensacola Florida.... Coast Guard Choppers fly low at times....If I am flying in a legal zone, who is at fault?

Definitely your responsibility to get out of the way of helicopters, they make enough noise and travel slow enough that you should hear and see them in time to get out of the way, that is partly why they are allowed down below 500m.    You do need to fly from an open location though, if you are sitting on the beach below the cliff then you can't see them coming from behind the cliff and quite likely wont hear them either.

Nigel_ Posted at 2017-2-22 15:13
If you kill it in the air it doesn't instantly disappear out of the way, in fact it can move well over 2x faster under power than it can with the motors off.  By killing the motors it does however become an uncontrolled hazard to anyone on the ground beneath.

You might want to check that arithmetic to see how fast a falling Phantom travels.
The idea of killing the motors to get out of the way of a plane sounds exciting but in practice, being able to see that your Phantom really is in the path of an aircraft would be near impossible with parallax and distance.

Labroides Posted at 2017-2-22 15:20
You might want to check that arithmetic to see how fast a falling Phantom travels.
The idea of killing the motors to get out of the way of a plane sounds exciting but in practice, being able to see that your Phantom really is in the path of an aircraft would be near impossible with parallax and distance.

That arithmetic would be far too complex for me to work out!  Acceleration due to gravity is OK, but calculating the aerodynamic drag of the falling aercraft, the deceleration rate of the propellers, the acceleration rate of the propellers in reverse, the lift of the reverse spinning propellers, the effect of instability, the rate of spin of the falling aircraft, the ability of the gyroscopic forces to stabilise the falling aircraft etc. is way beyond my ability...

g=        G * M / r2
=        (6.67 * 10-11) * (5.98 * 1024) / (6.378 * 106)2
=        9.81 meters/second2

Object takes 2.59 seconds to fall 33 meters on Earth
The object has had a average velocity of 12.72 meters per second after falling for 33 meters on Earth. This is an average of 45.79 kilometers per hour, and 28.45 miles per hour.

So in theory...It could fall quick enough to escape a collision.

So, if it was at eye level to you, how high do you estimate the plane was flying?

Nigel_ Posted at 2017-2-22 15:29
That arithmetic would be far too complex for me to work out!  Acceleration due to gravity is OK, but calculating the aerodynamic drag of the falling aercraft, the deceleration rate of the propellers, the acceleration rate of the propellers in reverse, the lift of the reverse spinning propellers, the effect of instability, the rate of spin of the falling aircraft, the ability of the gyroscopic forces to stabilise the falling aircraft etc. is way beyond my ability...

You are making it harder than you need to.
The Phantom under power can only descend at 3 metres/sec.
Falling, it can attain a much greater speed, so much more that calculating exactly how much isn't needed.

Labroides Posted at 2017-2-22 16:25
You are making it harder than you need to.
The Phantom under power can only descend at 3 metres/sec.
Falling, it can attain a much greater speed, so much more that calculating exactly how much isn't needed.

Put it in sports mode and fly horizontally out of the way and you can achieve 46mph according to the specifications, with the motors off it will never manage 23mph downwards.  If the plane is low enough to hit the Phantom, which is unlikely, then by turning the motors off you are just as likely to fall into the planes path as to move out of it unless you see the plane in plenty of time.  

Simultaneously flying horizontally and down and switching to sports mode  which gives you extra speed both horizontally and down must give you the best chance of avoidance, and remember to move to the planes left just in case it also takes avoiding action.

Nigel_ Posted at 2017-2-22 17:57
Put it in sports mode and fly horizontally out of the way and you can achieve 46mph according to the specifications, with the motors off it will never manage 23mph downwards.  If the plane is low enough to hit the Phantom, which is unlikely, then by turning the motors off you are just as likely to fall into the planes path as to move out of it unless you see the plane in plenty of time.  

Simultaneously flying horizontally and down and switching to sports mode  which gives you extra speed both horizontally and down must give you the best chance of avoidance, and remember to move to the planes left just in case it also takes avoiding action.

Like I said ... you need to check your arithmetic.
You said .. "with the motors off it will never manage 23mph downwards"

23mph = 10.3 metres/sec
I just checked the telemetry from a recent case of a falling Phantom
From 200 ft to 32 feet its average velocity was 13.7 metres/sec
From 100 feet to 32 feet its average was 17.5 m/s

But the whole idea of quick action to get out of the way of an aircraft is pretty silly.
From your position on the ground you have very little chance of correctly assessing how far away you are from the path of an oncoming aircraft or even what direction to move.

The shots were nicely done, thanks for sharing.

Labroides Posted at 2017-2-22 18:52
Like I said ... you need to check your arithmetic.
You said .. "with the motors off it will never manage 23mph downwards"

You should be able to judge reasonably accurately which side of you the aeroplane is going to pass, if your drone is in sight then you probably do know which way is best to go horizontally.   It is however almost impossible to accurately judge the height of an aeroplane unless you happen to be on a hill at around the same level as it.

Do you have a link to that telemetry?  I guess it wasn't falling with the motors powered off?

AlecW Posted at 2017-2-22 15:17
When it happed to me the plane came from behind a bunch of big trees that are 200 feet away from where I was standing.  You won't even have time to CSC.

Can you CSC in the air ?

When I do the two sticks back or lock down the left stick - P3S just descends with motors still running ... the motors only stop once sitting on ground.

Nigel

solentlife Posted at 2017-2-23 05:38
Can you CSC in the air ?

When I do the two sticks back or lock down the left stick - P3S just descends with motors still running ... the motors only stop once sitting on ground.

Yes, for the P4 it is: left stick full down and full right, then press the RTH button, the aircraft will then fall out of the sky destroying itself and anyone or anything it happens to hit on the ground.

KM5RG-Robert Posted at 2017-2-22 16:13
So, if it was at eye level to you, how high do you estimate the plane was flying?

I would estimate 150ft

DJI-Jamie Posted at 2017-2-23 00:20
The shots were nicely done, thanks for sharing.

Thank you!

Here is the unedited clip of the fly by, you can better see how low I was flying and how low the plane was actually flying in relation to the cliff side

The Dax Posted at 2017-2-22 10:55
Same issue in Pensacola Florida.... Coast Guard Choppers fly low at times....If I am flying in a legal zone, who is at fault?

You and the helicopter pilot are both responsible for maintaining separation from each other, but he; being a manned aircraft, has the right of way.

raymarz Posted at 2017-2-24 08:29
I would estimate 150ft

Sure looks lower than that in the screenshot of the last video.

Maybe next time, fly a kite at 400ft in the area you want to fly, aeroplanes have to give way to kites so it will ensure that your drone is safe.

Divers do the same thing, except that they call it a buoy.

The Dax Posted at 2017-2-22 16:03
g=        G * M / r2
=        (6.67 * 10-11) * (5.98 * 1024) / (6.378 * 106)2
=        9.81 meters/second2

mind blown!

Nigel_ Posted at 2017-2-25 17:26
Maybe next time, fly a kite at 400ft in the area you want to fly, aeroplanes have to give way to kites so it will ensure that your drone is safe.

Divers do the same thing, except that they call it a buoy.

wow thats an awesome thought.....does that really work....and it sounds much safer that way!