Crashed MA2 in first flight, what to check ?

[bjhirsch]

Got my MA2 on Friday & went out to test it Sunday. All went well until I prepared to land. At the hight of approx 3-4 meters my MA2 was suddenly attacked by a bird (just saw a fast grey flash hitting my drone); which felt out off the sky and into a not too rigid bush smoothening the impact. I got 2x lucky as the drone hit the bush with the back first , so Gimbal & camera looked protected. I switched off the drone and checked it over carefully, seeing. only a slight scratch mark in the middle of one back leg. 3 out of 4 propellers are impacted / 2x with cuts and one even broke the propeller plastic notch for holding the prop in the motor, so I changed all four.

I switched the drone on again .. no error messages & gimbal acts normal, I took a quick test flight and drone is stable in the air ... no shaking or unusual hoover; gimbal is reacting to gimbal up & down commands

Is there anything else I should check ??? I assume if one of the back legs would be bend I would see it when flying .. as it folds correctly ?

Thanks for any suggestion

PS .. the drone was lying in the bush after impact and continued to cut leaves, the motors did not stop on impact even as the props were blocked / could not turn as stopped by branches.
I recall that my mini stopped the motors directly after an impact with a bush, is there a setting for the emergency stop I should double-check? Currently, motor stop is on emergency only in app

A (very lucky) Bjoern

 

[Dedal]

There's not much you can do if it still turns on, functions and flies as it's supposed to. Take a good, careful look at it, scratches are not important, take off propellers, look at the motors, try spinning the them by hand to see whether there's resistance (if there's a debris inside, you can hear it), look at the gimbal, is it still seated well, nothing blocked it: Try wiggling the legs (not too much force) to see it there's any play in them, open / close them, look if the sensors are obstructed / smashed up, check if your SD card is seated properly, if everything looks all right, go and fly, be sure to watch the app more frequently, it will be telling you if anything went wrong internally for sure.

Btw, congrats, that was lucky.

Fly safe.

 

[Deleted member 103366]

Look at the CSC stuff in the manual and perhaps play with it with the drone sat on the ground or floor. I don't know if MA props will bite as viciously as Phantom 3 props but I am sure MA props can still hurt fingers that get in their way whilst trying to rescue a crashed but still attempting to fly drone

 

[bjhirsch]

here is what I mean, the flight logs shows that the motor is blocked after hitting the bush .. but the drone did not stop the motors even if the props could not turn until I switched the craft off. I thought there is a sensor that when an impact is recorded the motors are stopped automatically?

 

[Dedal]

I thought there is a sensor that when an impact is recorded the motors are stopped automatically?

There should be CSC setting (Combination of Stick Commands) inside Fly app (I'm using Go4) where you can stop the motors in emergency situation:



Also, in MA2 user manual on the pages 44 / 45:

https://dl.djicdn.com/downloads/Mavic_Air_2/20200511/Mavic_Air_2_User_Manual_v1.0_en.pdf

Edit: You can read abut CSC here:

Is there a way to disable CSC on Mavic?

I'm not a big fan of the CSC feature as I feel it could cause the drone to crash if you accidently use the controller in a wrong way. Any way I can disable this feature? Sent from my Pixel XL using MavicPilots mobile app

mavicpilots.com

 

[bjhirsch]

Thank you , I thought in a emergency situation the motors would stop automatically, so now I know that I need to do in addition the stick command.
So the difference to use the command in emergency only vs CSC manover is not very clear to me .. the second one allows it to happen during a flight & as well for after landing .. while the first one .... ???? Need a emergency trigger from the drone ????

 

[Dedal]

CSC option in go app question

In the app there are 2 option on CSC. What is defined an emergency ? "for use in emergencies only" vs CSC manovouver ?

forum.dji.com

Post #4 - Quote:

"Within the various versions of DJI consumer drones, DJI created the Combination Stick Command (CSC) to both start and stop the motors. Initially, this was the only way to control the motors:



A problem was realized with agressive flight, where the CSC could be initiated accidentially, resulting in the aircraft crashing/falling out of the air due to accidential motor stoppage. With the evolution of the GO/GO4 app, DJI introduced the landing method of motor shutdown by simply holding the throttle down, after the aircraft has landed, for three seconds, and the motors shutdown. This has become the standard way of shutting down the motors on landing. But the inflight CSC problem remained a possiblity.

So with the P4, DJI introduced an alternative control combination for emergency motor shutdown. But long time users of DJI products didn't like this methodology. So with the Mavic, DJI programmed additional intelligence into the flight controller that allows the pilot to choose how the motors can be stopped in mid-flight....

That's what you are referring to in your screenshot. Since stopping the motors in mid--flight WILL cause the aircraft to crash, if you select "For use in emergencies only", then the Mavic motors can only be stopped in mid-flight when the Mavic flight controller detects a CRITICAL error. If you select "CSC Maneuver", then you (the pilot) can deliberately stop the motors or accidently stop the motors in mid-filght with a simple CSC and it will stop the motors...

So if you want to fly agressively and not worry about accidential CSC commands, then select "For use in emergencies only", and the GO4 app will protect you. If your an old-timer and like full control as the pilot-in-command, then select "CSC Maneuver" and be carefull to not ever push the sticks to the CSC position while in flight....."

CSC vs Emergency only??

Hi Guys! I have a M2P. Untitled.jpg (0 Bytes, Down times: 9) Download attach 2019-1-12 Upload Can someone please explain the difference when stoping the motors between CSC Manuever and For use in emergencies only? If I understand corectly: - CSC Manuever - every time you...

forum.dji.com

Post #7, question quote:

"So if I understand correctly, if I have set it on "CSC maneuver", if I hold the sticks in displayed position the motors will stop, and if I have in on "for use in emergencies only" the motors wont stop if I do this move with sticks? "

Post #8, answer quote:

"No. If you set to CSC it will take a couple of seconds to stop the motors. If you set it to Emergency it will stop motors immediately. Either way, it's coming down.

Looks like turning this feature off is no longer an option, probably a good thing."

----------

I never had to use any of those, because I had no need for it (thankfully), I use the stick combo when starting motors, just to change the routine a bit.

 

[bjhirsch]

Thank you @Dedal for the very detailed explanation, my (wrong) assumption was that if an emergency "stop" only happens when there is an CRITICAL error from Mavic flight controller this would stop the motors automatically after the signal is received without any manual stick input needed.. but now I understand that the controller needs to send the signal AND I need to push both sticks as described .... complicated world

 

[Dedal]

You are welcome.

 

[boblui]

That's a bad design. If the drone is flipped over the first thing the FC will do is to restore the attitude by applying appropriate controls to the motors but if this cannot be achieved within a reasonable amount of time, the FC should stop the motors. This has been seen in other Mavics but the MA2 will keep trying indefinitely ? Hope DJI will correct this in the next firmware release.


The most vulnerable part of the drone is always the gimbal. I will try rocking the drone by repetitively moving the elevator sticks up and down to the limits quickly while the craft is hovering and see if the framing of the live image feed remains stable. Then repeat on the aileron control .

 

[J2ps]

After a crash it’s always good to recalibrate IMU, compass, and gimble. Even if it doesn’t prompt you.

 

[MrLatte]

If you continue to read the DJI Forum post linked to above they clarify the settings of CSC:

"...if set to "on emergency use only" then the CSC command can only be initiated by the pilot if the drone detects it is already in an emergency or unstable angle of flight or position. During normal flying staus/position or stability, CSC cannot be initiated."

See post #12 in the DJI forum thread mentioned above includes info from DJI Technical Support:

CSC vs Emergency only??

Hi Guys! I have a M2P. Untitled.jpg (0 Bytes, Down times: 26) Download attach 2019-1-12 Upload Can someone please explain the difference when stoping the motors between CSC Manuever and For use in emergencies only? If I understand corectly: - CSC Manuever - every time...

forum.dji.com