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Mavic bit me like a bat out of hell...guess it was my fault

jirestre

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Three weeks ago I was whale watching in Los Cabos on a small boat. No adequate space for take off/landing, so I decided to do a hand release (not the first time I was doing that, but certainly the first time on a boat with wind and waves).
Turned off the downward VPS and left the front collisioning system on (I guess this was my mistake, but please someone confirm that the mavic behaviour was due to this). I catched the mavic from below with the hand high in the air and proceed to initiate the motors. At this moment the mavic reeved up with all it's power, I tried not to let it go (I was afraid to let go, because I was not accelerating and really didn't understand what was happening). Finally it flew away from my hand, hitting my left thumb in the process and flew a few meters behind the boat.
From what I see from the attached log (first time using this tools - 0s when motors are initiated). As soon as I started the rotors, the emergency brake kicked in and the motors accelerated and that's when it went away from my hand.
This is my first incident in two years. I know hand catching and releasing is not a recommended practice but really the boat was small and the whales were jumping like crazy.
Any comments are welcome.

regards,
Jorge

attached: the log, my thumb, and what I missed filming.
20170206_124548.jpg
G_20170211_1253244.gif
 

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  • FLY057.csv.zip
    3.3 MB · Views: 8
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My first thought was ouch, second was wow you got lucky! Lol

Wishing you a fast recovery
 
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Here's my theory: I'm assuming the Mavic was getting a good GPS lock by the time you initiated the launch. As soon as you start the motors, the Mavic is basically in flight and will try to maintain its vertical and horizontal position, just as it does when in a hover. At this point, since you were still holding the Mavic "in place" relative to yourself, any movements of the boat would have translated to the Mavic, making it think it was moving forward, back, up, down, left or right. Since there were no stick inputs telling it to move, the Mavic tries to counter those movement as if they were wind or some other external force. This may have been exacerbated by the fact that it was trying to brake to avoid a forward obstacle. The braking maneuver can apply a lot of throttle, and if the Mavic still thought it was moving forward while trying to brake, it would apply more throttle to try and stop.

In this case, you probably would have been better off to let it go as quickly as possible, rather than hold onto it.

That's one theory, anyway.
 
I laughed out loud when I read the title. Sorry you got hurt.

I'm very used to catching my P3 but only recently got the Mavic and getting used to catching it. :)
 
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Wow could you not have made that picture a bit smaller, I am eating lunch here ;-) This does confirm my thoughts on not trying to hand launch or catch the Mavic.

I sliced the top of a knuckle off once and stuck the flap back down with tape until it clotted and healed, was great apart from it won't bend all the way now. What did you do with that, pull the rest of it off or tape it up?Just curious :)
 
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Here's my theory: I'm assuming the Mavic was getting a good GPS lock by the time you initiated the launch. As soon as you start the motors, the Mavic is basically in flight and will try to maintain its vertical and horizontal position, just as it does when in a hover. At this point, since you were still holding the Mavic "in place" relative to yourself, any movements of the boat would have translated to the Mavic, making it think it was moving forward, back, up, down, left or right. Since there were no stick inputs telling it to move, the Mavic tries to counter those movement as if they were wind or some other external force. This may have been exacerbated by the fact that it was trying to brake to avoid a forward obstacle. The braking maneuver can apply a lot of throttle, and if the Mavic still thought it was moving forward while trying to brake, it would apply more throttle to try and stop.

In this case, you probably would have been better off to let it go as quickly as possible, rather than hold onto it.

That's one theory, anyway.

Sounds right. I'd embellish the above by adding if the boat is moving forward, then best to hand launch at the very rear of the boat. As the Mavic will want to go to where it was and that is aft of the boat. Have to think of the safety of everyone on board as well as the sanity of the Mavic's control laws.
 
Here's my theory: I'm assuming the Mavic was getting a good GPS lock by the time you initiated the launch. As soon as you start the motors, the Mavic is basically in flight and will try to maintain its vertical and horizontal position, just as it does when in a hover. At this point, since you were still holding the Mavic "in place" relative to yourself, any movements of the boat would have translated to the Mavic, making it think it was moving forward, back, up, down, left or right. Since there were no stick inputs telling it to move, the Mavic tries to counter those movement as if they were wind or some other external force. This may have been exacerbated by the fact that it was trying to brake to avoid a forward obstacle. The braking maneuver can apply a lot of throttle, and if the Mavic still thought it was moving forward while trying to brake, it would apply more throttle to try and stop.

In this case, you probably would have been better off to let it go as quickly as possible, rather than hold onto it.

That's one theory, anyway.

No offense to your theory but isn't it just basic obstacle avoidance, or failing that the landing precision settings.
the few times ive hand caught, it does the exact same thing. Just goes full power while you fumble trying to power down

OP, were you in sport mode?
I saved my mavic from destruction by taking 2-3 propellors at full stick
had cuts were all over both hands but baby cuts, like paper really
 
No offense to your theory but isn't it just basic obstacle avoidance, or failing that the landing precision settings.
the few times ive hand caught, it does the exact same thing. Just goes full power while you fumble trying to power down

Forward OA won't cause the Mavic to try to move backwards or away from the obstacle; the Mavic just tries to stop if it senses an object in front of it. The full power you're talking about is when the Mavic senses an object below it, but the incident the OP is talking about happened during takeoff with VPS disabled. Downward OA and Landing Precision would have played no part in it.
 
Ouch! I must admit, you all have balls of steel! When I flew my P3 Standard and P3 Pro - I had no concerns about hand catching. Now that I have the Mavic, I have not even attempted it. It just seems that with the profile being so low - one little mishap and you are paying for it in blood! Granted though - so far I have only flown in areas that I had a suitable landing area. If I was on a boat - I am sure I would be the first to say "what's the worst that could happen..." famous last words!
 
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No way that I ever intend to hand launch or catch a Mavic. I've played with my daughter's inexpensive and light quadcopter, and even the propellers of that can give your fingers a good whack. Absolutely no interest in finding out how the much faster and bigger propellers of a much heavier quadcopter like the Mavic feel.

Especially dangerous to hand catch while on a boat. When you're on dry land, at least you have a hope of not upsetting the Mavic's control system's desire to hover in a fixed location too much. But if you're on a rocking and tossing boat, then of course you can expect the Mavic to disagree with you violently when you try to hand catch it. It has no way of knowing that it's not being buffeted by strong winds.
 
Last edited:
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Has the Mavic been quarantined to monitor for rabies?

Speedy recovery!
 
Thanks everyone that jumped in.
It wasn't in sport mode. I tend to agree with what JLane wrote, the boat movements scared the Mavic.
Mfarris2: Thanks for the recommendation of butcher gloves, believe me or not, I aready tought on that.
Finally to all those concerned, finger almost mended right now.

regards,
Jorge
 
You mentioned that you turned off the VPS but the front sensors were still active. So my question is this, as you were landing, were you pointing the MP toward you?? This would have alerted the front sensors to try to avoid you.
I'm only guessing here but if you had BACKED the MP toward you, the front sensors would never have "seen" you and you probably would have be OK.
 
You mentioned that you turned off the VPS but the front sensors were still active. So my question is this, as you were landing, were you pointing the MP toward you?? This would have alerted the front sensors to try to avoid you.
I'm only guessing here but if you had BACKED the MP toward you, the front sensors would never have "seen" you and you probably would have be OK.
Yeah I know, but this happened at launch and the MP was pointing away from me.
 
Three weeks ago I was whale watching in Los Cabos on a small boat. No adequate space for take off/landing, so I decided to do a hand release (not the first time I was doing that, but certainly the first time on a boat with wind and waves).
Turned off the downward VPS and left the front collisioning system on (I guess this was my mistake, but please someone confirm that the mavic behaviour was due to this). I catched the mavic from below with the hand high in the air and proceed to initiate the motors. At this moment the mavic reeved up with all it's power, I tried not to let it go (I was afraid to let go, because I was not accelerating and really didn't understand what was happening). Finally it flew away from my hand, hitting my left thumb in the process and flew a few meters behind the boat.
From what I see from the attached log (first time using this tools - 0s when motors are initiated). As soon as I started the rotors, the emergency brake kicked in and the motors accelerated and that's when it went away from my hand.
This is my first incident in two years. I know hand catching and releasing is not a recommended practice but really the boat was small and the whales were jumping like crazy.
Any comments are welcome.

regards,
Jorge

attached: the log, my thumb, and what I missed filming.
View attachment 6756
View attachment 6757

Hi, I'm going to Cabo on Sat and plan on using my MP to film the whales. Did you have issue calibrating the compass because of the metal on the boat? Thanks
 
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