Injuries

[Mahallati]

Set up my M2p on a long tail boat in Thailand. And as soon as I started the propellers it immediately flew backwards between my feet and cut me up

Anyone else faced this kind of issue?

 

[Mahallati]

 

[Former Member]

Ouch! Was the boat moving? Your M2 might have still been in atti mode, but it shouldt have bitten you.

Look on the bright side, at least youre in Thailand, The Land Of Smiles. Things could be worse.

 

[Mahallati]

Boat was moving. But I only started the propellers. Boat was about to stop so I can fly, and boat will continue so m2 can follow. But it went crazy and flew backwards towards my feet

 

[kilomikebravo]

If you didn't "slide to takeoff" or, push the left stick up then, it's a mystery. Sorta sounds like the Mavic was hovering and the movement of the boat took you and your feet into her.

But, as ALWAYS, flight logs are required to try and determine what occurred.

 

[Kilrah]

It sucks, but the behavior is perfectly normal and expected. Once you start the motors the slightest rocking of the boat which causes the drone to get lower will make it consider it's in flight and add power to maintain the original height. And since it's in GPS mode, also it's position so if the boat moves you move into the now stationary aircraft.

 

[Mahallati]

It sucks, but the behavior is perfectly normal and expected. Once you start the motors the slightest rocking of the boat which causes the drone to get lower will make it consider it's in flight and add power to maintain the original height.

I think that’s exactly what’s happened

 

[Cymruflyer]

Plus, even if you think the boat has stopped, as you stated it was about to, that boat is on water and the water is flowing. Therefore for what you think is stopped in GPS language that boat is most likely still moving somewhere, so not a good idea to fly off a boat.

 

[GH02050]

Thank you for posting this experience. I fully intent to take my drone with me offshore fishing, whale watching etc. So understanding the drones behavior in these situation is very important to me. I wouldn't have thought the drone would assume it's in the air until it actually took flight but it makes perfect sense the way Kilrah describes it.

When I'm on the boat/water my plan is to take off from and land from my hand. For take-off I plan to use the auto feature while I have a firm grasp on the lower body of the drone (simply let it fly once the auto takeoff initiates) For landings, I will disable the landing and collision avoidance sensors and fly the drone right over the aft of the boat where I will firmly grasp the lower body of the craft with my right hand and power down the props with my left. Of course all of this is very easy to do on land. I know it will be more challenging in 4 foot seas

 

[Air_Joe]

Sorry to see this bro.
Hope u recover soon.

However thks for the post, its a grat learning experience for us!

So for me lauching off a boat, probably i would have wait for a conplete stop or at least wear a high cut boot learning from your painful experience.

Anyway enjoy your trip!
Khop khoon kup!

 

[Kilrah]

A drone you want to use from a boat should not be in GPS mode, but should have ATTI mode available. That makes the Mavic a poor choice, unless you use the available tricks to enable it.

 

[sar104]

It sucks, but the behavior is perfectly normal and expected. Once you start the motors the slightest rocking of the boat which causes the drone to get lower will make it consider it's in flight and add power to maintain the original height. And since it's in GPS mode, also it's position so if the boat moves you move into the now stationary aircraft.

That's the second or third incident of that kind that I've seen here.

A drone you want to use from a boat should not be in GPS mode, but should have ATTI mode available. That makes the Mavic a poor choice, unless you use the available tricks to enable it.

ATTI mode will prevent the attempt to hold position but that isn't necessarily an improvement. Instead it is going to set pitch and roll to zero, which means zero airspeed. It's just as likely to move rapidly relative to the boat, but now in an unpredictable direction. A better strategy is possibly to use auto takeoff in P-GPS, or manual engine start with immediate full throttle to clear the boat.

 

[madkaw]

I thought when on the water, you suppose to disable precision landing and changing RTH to remote so it doesn’t confuse the drone positioning. I remember seeing a youtuber mentioning this when he was filming from/on his kayak.

 

[Kilrah]

ATTI mode will prevent the attempt to hold position but that isn't necessarily an improvement. Instead it is going to set pitch and roll to zero, which means zero airspeed.

NO!

Zero pitch/roll does NOT mean zero airspeed, it means "continue on your drift" aka no acceleration, or just "do nothing". When taking off from a boat moving at 5mph in ATTI mode the aircraft is moving at 5mph with the boat, and when lifting off it just stays flat and basically continues to mostly fly in the same direction at the same 5mph, only the little bit of airframe drag, wind influence and attitude imprecisions will (slowly) affect it, which is MUCH easier to correct for with small inputs. Most importantly the aircraft will not do any action/movement of its own.

In GPS as soon as the aircraft considers it has taken off it will do everything it can to enforce the ground speed requested by the stick, even if that means going full power against you or the boat, it's fast and it's very hard for you to quickly find the right stick input to give to have it follow the correct direction and speed of the boat. You absolutely do not want that.

 

[sar104]

NO!

Zero pitch/roll does NOT mean zero airspeed, it means "continue on your drift" aka no acceleration, or just "do nothing". When taking off from a boat moving at 5mph in ATTI mode the aircraft is moving at 5mph with the boat, and when lifting off it just stays flat and basically continues to mostly fly in the same direction at the same 5mph, only the little bit of airframe drag, wind influence and attitude imprecisions will (slowly) affect it, which is MUCH easier to correct for with small inputs. Most importantly the aircraft will not do any action/movement of its own.

In GPS as soon as the aircraft considers it has taken off it will do everything it can to enforce the ground speed requested by the stick, even if that means going full power against you or the boat, it's fast and it's very hard for you to quickly find the right stick input to give to have it follow the correct direction and speed of the boat. You absolutely do not want that.

Zero pitch and roll doesn't mean immediate zero airspeed - it means that the aircraft airspeed asymptotes to zero, and that transition is not slow. If you prefer to think about the converse situation, consider launching in ATTI mode in the wind - the aircraft rapidly matches wind speed. Your example of launching from a slow-moving boat in zero wind is not going to be typical.

 

[Kilrah]

the aircraft airspeed asymptotes to zero, that transition is not slow.

Slow is relative of course but what matters is that passively drifting to zero is MUCH slower than the aircraft actively fighting to reach zero ASAP.

ATTI drifts to zero in a few seconds at low power giving you time to react, GPS does it in half a second at high power which you can't react to and can cause a lot more damage. The difference is a smooth takeoff/landing with a bit of training or the situation in the OP which you can't really train for.

I've been doing boat shoots for 2 seasons with a Phantom. ATTI is a piece of cake, GPS is really dangerous.

In ATTI when you come to land you give it the right direction/speed plus a little, you can let the stick go and catch without issue while it's still gliding smoothly next to you. Try that with GPS - the instant you let go of the stick it's gone. Same with launch, in ATTI you can safely hold it for ever while it's already in the air until you're ready without giving any input, and when you let go you have no problem to get to the stick and start flying it before it's slowed down too much to become an issue.

 

[sar104]

Slow is relative of course but what matters is that passively drifting to zero is MUCH slower than the aircraft actively fighting to reach zero ASAP.

ATTI drifts to zero in a few seconds at low power giving you time to react, GPS does it in half a second at high power which you can't react to and can cause a lot more damage. The difference is a smooth takeoff/landing with a bit of training or the situation in the OP which you can't really train for.

I've been doing boat shoots for 2 seasons with a Phantom. ATTI is a piece of cake, GPS is really dangerous.

In ATTI when you come to land you give it the right direction/speed plus a little, you can let the stick go and catch without issue while it's still gliding smoothly next to you. Try that with GPS - the instant you let go of the stick it's gone. Same with launch, in ATTI you can safely hold it for ever while it's already in the air until you're ready without giving any input, and when you let go you have no problem to get to the stick and start flying it before it's slowed down too much to become an issue.

Since you have tried both I can't criticize your conclusion on which works better. The landing case I would expect to work better since you already know how the wind is affecting it.

 

[xspwhite]

Set up my M2p on a long tail boat in Thailand. And as soon as I started the propellers it immediately flew backwards between my feet and cut me up

Anyone else faced this kind of issue?

I would say that these really are not the kind of toys to play with without wearing the proper gear.

 

[m chaussettes]

When I would take my kids to the airport it used to scare the heck outta me that they would go wondering off. I would strap them into the plane before I did anything else to make sure that wouldn't happen.

I had heard about too many kids turned into hamburger.

Those drone blades can be very dangerous and deserve healthy respect. At speed sharp as a razor and of course in the right place...

I know i am preaching to the choir but stories like this could always have gone a lot worse.

 

[m0j0]

Seems like the way to do it would be with the auto takeoff. I would also say the boat should probably be at a full stop.