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Boat or Ship Launch or Take Off Warning

ajlholt

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Here is a cautionary tale for boat take-offs. I had permission to fly my Mavic Pro from the back of a ferry in the Mediterranean. I had hoped to fly around the vessel to practice getting some stills and video while at sea and I was given a clear deck space at the rear of the ship with railings around it. Despite the metalwork all around and the metal deck I had a good Ready to Fly signal and plenty of satellites. My plan was to take off, hover at around 3' to check controls were OK and then go through my flight sequence. I took off and the drone immediately flew backwards into the railings, smashed its props and dropped into the sea...

I had, in retrospect, not thought everything through propertly. The drone did not fly backwards; it stayed where it was in a GPS hover and the ship's railings came forwards at it with the unfortunate consequences.
The lesson is: If you are taking off from a moving launch site, remember that the drone does not know that you and the controller are moving. It wants to stay in a fixed position from take-off until instructed otherwise.

Therefore if launching from a boat, always make sure that the vessel is moving away from your launch position and that no part of the moving vessel will move towards the drone.
It is a great pity that it does not seem possible to turn off the GPS mode on the Mavic. That would have been really helpful. Please fix that DJI.
Any other boat launch tips welcome. Some people like to disable sensors and some to leave them on but land backwards.
 

netfolks2000

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To fly in atti mode out there in the sea breeze would be another problem, a bad drift in the wind direction, with no GPS control at all, only your talent in flying with constant moment by moment monitoring of height and direction. Can you do that? It can be rather wild and require a lot of nerve. GPS is our friend, keeps us stable. It was not a good decision to launch from a moving vessel. I don't know how fast it was going but you risked several things like being able to keep up, maneuver the drone around a moving object with no way to go to it if it had to go down for any reason. Your speed required in order to fly toward the front of the vessel would be added to the actual speed of the drone to get there. Coming back again that speed would be added to the current speed of the drone. Conditions turning back again would dramatically change. The wind could also double the effort to go one direction. If the vessel was going straight into the wind and you did make it around the front, you'd be going really fast coming back to the rear. Pretty complicated. I'm sure someone else can describe those numbers better than I. If the vessel was only going at 20 mph and you had a slight 10 mph breeze you'd already have a 30 mph force to overcome. That alone is a no fly day.
 

netfolks2000

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To fly in atti mode out there in the sea breeze would be another problem, a bad drift in the wind direction, with no GPS control at all, only your talent in flying with constant moment by moment monitoring of height and direction. Can you do that? It can be rather wild and require a lot of nerve. GPS is our friend, keeps us stable. It was not a good decision to launch from a moving vessel. I don't know how fast it was going but you risked several things like being able to keep up, maneuver the drone around a moving object with no way to go to it if it had to go down for any reason. Your speed required in order to fly toward the front of the vessel would be added to the actual speed of the drone to get there. Coming back again that speed would be added to the current speed of the drone. Conditions turning back again would dramatically change. The wind could also double the effort to go one direction. If the vessel was going straight into the wind and you did make it around the front, you'd be going really fast coming back to the rear. Pretty complicated. I'm sure someone else can describe those numbers better than I. If the vessel was only going at 20 mph and you had a slight 10 mph breeze you'd already have a 30 mph force to overcome. That alone is a no fly day.
I am very sorry you lost the drone, unable to even retrieve it. By sharing your story you will hopefully keep someone else from doing that. I thank you for taking time to write about your experience. I wince thinking about how you must feel having lost it.
 
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Mossiback

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Bummer. I have seen a lot of crash videos of launches from moving boats. One guy successfully launched from the back of a cruse ship only to see his Phantom unable to keep up with the ship and land in the sea.
 
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BD0G

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GPS can actually be disabled. Tin Foil sheet (1) over the top of the Mavic. Not wrapped around the air vents (Overheating can occur) then tape it down with Scotch tape. I would strongly suggest against unless you are an ATTI Mode flying GOD. Lots of uncertainty.

Hand Launch with Left stick up would have been my method.
 

FlyGuy8675309

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GPS can actually be disabled.

Would not have helped this guy. Hover is a hover and if the ground beneath you is moving.. well do the math Only thing that would have helped is if the VPS recognized the changing launch-point visuals and "kept" up with the ship -- ie throttled forward matching the speed of the boat.

Those Air Force and Coast Guard guys make it looks so easy. :D
 
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anzacjack

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Experience makes us all smarter. I’m guessing you didn’t have a lot of stick time on the mavic before this mishap. Nothing worse than a total loss.
 
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ajlholt

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In fact I had had many hours of stick time on the Mavic but this happened very quickly. From take-off to impact was about one second... That is why I wanted to give a warning to prevent it happening to other people.
 
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Ripper7620

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I was under the impression that it is common practice to always launch and retrieve from the back of the boat, but haven't had the chance to try it yet.
 

Mossiback

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I was under the impression that it is common practice to always launch and retrieve from the back of the boat, but haven't had the chance to try it yet.
Launch from a boat from a position with the least obstacles to hit and with the least amount of metal that may throw off the compass. It is safest to be stationary but if moving there cannot be anything that will hit the Mavic while it holds its position. Retrieval is more difficult the more the boat is moving so protective gloves would be a good idea to use for a hand retrieval.

YouTube has a lot of videos showing how difficult it can be.
 

rfc

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Another thing to be mindful of: Don't start the motors until you are READY to take off imminently! There are at least two threads recently on the issue of a vessel lurching vertically, causing the bird to spool up the props and inadvertently take off without warning.