CAUTION - DJI NAZA V2 GPS Unexpected Take-Off Hazard

[Mike Mas]

---

Be advised if you are using the Naza V2- GPS your machine will take-off with no prior warning - which could result in an accident or serious injury.
Problem: DJi’s new “Non-Signal” firmware which monitors the receiver for a “No Signal” status them automatically engages failsafe has no priority to lock out this feature while on the ground.

Event: Pilot engages and starts the motors – if the pilot does not move the cyclic yaw or throttle sticks for a short period of time - the Naza instantly enters “fail-Safe” mode and in a few seconds goes to full throttle in an attempt to reach failsafe altitude therefore causing the pilot to think the machine is in a fly-away state.

My Event: I set the machine on the runway spooled up the motors, after a few seconds, I walked over to my FPV monitor to check the readout battery voltage - as I began to walk back to the machine, the multi blasted off the ground – As I held low throttle in hopes of reducing the ascent - I switched to failsafe with no results - next I flipped to ATTI to dump the GPS and my machine went to low throttle tumbled out of the sky, unknowingly, my 40+ years of reflex instantly added throttle in time to prevent the motors from shutting down and it nearly hit my truck and Linda as it sped back up to the ground.

I recommend that anyone using this Naza be aware of this error and take precautions when on the ground and spooling up the motors – remember if your in GPS mode you’ll have to move to ATTI to dump the fail-safe routine already started. DJI needs to address his problem with a update to prevent fail-safe engagement while the machine is on the ground.

Fly Safe!

Mike Mas

Bench test of error video attached

http://youtu.be/03VRozck72c

 

[Bartman]

Hi Mike,

Please check your video link and thanks for the info.

Bart

 

[rhoffart]

Here is a good link to the video

http://www.youtube.com/watch?v=03VRozck72c

 

[econfly]

Turn off receiver advanced protection and implement failsafe settings (triggered by signal loss) with your radio and receiver instead. Or, just don't idle on the ground in the first place, but if you do, center the throttle.

 

[tahoejmfc]

econfly is right. Also why would you every leave any copter at idle on the ground with the transmitter out of your hands? bad flying etiquette to idle copter on ground, it is not a gas model, but a modern computer controlled electric multi rotor that never needs to idle that long on the ground with no stick inputs

Turn off receiver advanced protection and implement failsafe settings (triggered by signal loss) with your radio and receiver instead. Or, just don't idle on the ground in the first place, but if you do, center the throttle.

 

[deluge2]

Where does the OP indicate that the transmitter was 'out of [his] hands'? It's not in his text that I can find...

econfly is right. Also why would you every leave any copter at idle on the ground with the transmitter out of your hands? bad flying etiquette to idle copter on ground, it is not a gas model, but a modern computer controlled electric multi rotor that never needs to idle that long on the ground with no stick inputs

 

[Tahoe Ed]

This is not the only forum/thread he has posted this in. Total debunked in other user test. It appears his Tx is not calibrated correctly and is not centered. Double flashes. If you don't want to use the feature, don't enable it. The same can be said for intelligent throttle control.

 

[Bartman]

yup, it seems that this post should be more geared towards what to do or not do if you use the Receiver Advanced Functions......if you use it then be aware that you shouldn't idle your motors on the ground without any stick inputs or the helicopter will enter failsafe.

I suppose DJI could program the feature to only function once the helicopter senses that it is airborne but the pilot can just as easily bump the throttle stick while doing something else which would have the same outcome as what Mike described in his video.

The moral of the story is, DON'T START YOUR MOTORS UNTIL YOU ARE READY TO FLY and please don't ever leave the heli unattended with the motors running.

 

[Bartman]

...............bad flying etiquette to idle copter on ground, it is not a gas model..........

maybe an example of negative learning but, fwiw, there's no requirement with gas engines to warm them before a flight. the manufacturers recommend that you start them and run them.

 

[Mike Mas]

Sorry about the link guys the correct link is below - Regardless of the cause, DJI still needs to fix the problem to prevent a protection mode designed for flying from occurring on the ground and possibly injuring someone - any way you look at it, its dangerous.

Bottom line is "Anything" that can cause a machine to lift off into flight with no input from the pilot is broken and needs to be fixed!

Hey guys - been doing this heli thing for a while now - rest assured its happening and a potential danger problem.

My machine does the same exact thing on a single flash as it does on two - Regardless - no matter how you twist it or what the problem is - the helicopter is; "TAKING OFF BY ITSELF" and going into a flight mode which can result in serious injury.

Bottom line is; the RAP feature needs to be disabled when the machine is on the ground - PERIOD!

This is a safety hazard and if you do a search on multi forums you'll see that it has happened to others since DJI incorporated this feature into the last firmware.

http://youtu.be/03VRozck72c

 

[rilot]

I cannot replicate what you describe.
Start motors, move sticks to middle and it will just sit there all day long.

 

[Mike Mas]

I have 3 other machines that don't do it as well - all I'm saying is that it can happen and I'm putting it out there in hopes of saving someone some grief. I didn't manufacture this - the Naza is going into failsafe because it does not see any pilot input - The RP needs to be disabled while the machine is on the ground or less than 10 meters from the home point.

 

[tahoejmfc]

If you watch the video you can clearly see this goof ball leaving his transmitter on the desk and waiting for the copter to go to failsafe. It appears his Tx is not calibrated correctly and is not centered. Double flashes. If you don't want to use the feature, don't enable it. The same can be said for intelligent throttle control.

I understand that Mike is a pioneer in the rc industry with a record breaking flight of 3 phantoms at the same time as well as claiming in his 22 page write-up that he worked for the national enquirer invading the privacy rights of celebrities as well as government officials by mounting a camera to a 8' heli and flying it up and over private property to spy. (must not know what the AMA is and understand its recommended guidelines as well as common sense and consideration for someones privacy rights)

The best thing for Mike to do is follow the directions for the naza and calibrate his transmitter properly, set the endpoints properly, verify in the naza software that he is at neutral points and has the travel amount set up right as well as turning the feature he is bitching about OFF.

Where does the OP indicate that the transmitter was 'out of [his] hands'? It's not in his text that I can find...

 

[tahoejmfc]

it is going into failsafe because your transmitter is not set up correctly, you can see the two flashes on the led that tell you you are having transmitter issues. GO READ THE MANUAL and setup your transmitter correctly and this problem will evaporate...

 

[Bartman]

..........I understand that Mike is a pioneer in the rc industry with a record breaking flight of 3 phantoms at the same time as well as claiming in his 22 page write-up that he worked for the national enquirer invading the privacy rights of celebrities as well as government officials by mounting a camera to a 8' heli and flying it up and over private property to spy. (must not know what the AMA is and understand its recommended guidelines as well as common sense and consideration for someones privacy rights)
..............

that must explain why he puts his full name in his thread titles :dejection:

 

[Bartman]

A4 Receiver Advanced Protection Function

You are asked to enable this function by connecting to the Assistant Software, please set it at the section of
Basic R/C

-
> Receiver Advanced Protection.
If you choose enable it, the FailSafe will be triggered if the following situations occur

during flight. According to the difference of the aircraft height, there are two situations.

a) Lower than 100m, the A/E/R channel is not at the

mid point
b)Higher than 100m, the A/E/R channel is not at the

mid point or the throttle stick is above the mid point.


In the GPS Mode or ATTI. Mode,if the requirement a) or b) is satisfied, and the output data of four channels

A/E/R/T have not changed for 20 seconds, then the aircraft will hover automatically.

After that, if the output data of four channels A/E/R/T still do not

any changes and last for 10 seconds, the autopilot system will think that the

data from receiver is abnormal, and then enter the FailSafe Mode.

Brief introduction of how to quit the FailSafe Mode

If there is any command change from the receiver,

the autopilot system thinks that the receiver is regained.


In ATTI. Mode and Manual Mode, it will quit the FailSafe Mode

automatically
.
In GPS Mode, please toggle the control modeswitch to the ATTI. Mode and
Manual Mode position to regain the control. Refer to the FailSafe section for more

details

Looking at the LED Descriptions on Page 24 of the NAZA V2 Quick Start Guide, it says a double blinking amber light indicates the sticks are not centered. Mike Mas's radio is just sitting there so I'd guess something is causing the NAZA to believe the sticks aren't centered, probably a bad radio calibration which should have been indicated in the NAZA Assistant when he set it all up.

Reading the Receiver Advanced Protection Feature above, if the heli is below 100m and the sticks are not at the midpoint, Failsafe will trigger which is what Mike Mas demonstrated in his video.

So Mike Mas does seem to have a point that the heli will trigger a failsafe provided you do what he did which was to first start the motors and then walk away (not recommended) from a heli that hasn't had an accurate controls calibration done and where you aren't familiar with the flashing LED's enough to know there's a problem.

I mentioned in the group build we're doing that the LED Indications page should be printed out in color (and probably laminated) and referred to regularly while out flying so that the indications can be accurately understood. It probably would have helped Mike Mas out if he had done that.

Bart

 

[econfly]

Bottom line is "Anything" that can cause a machine to lift off into flight with no input from the pilot is broken and needs to be fixed!

But the machine is getting input from the pilot. You have a function enabled that causes the machine to takeover flight controls when you provide static and non-centered input for a certain length of time. And that is exactly what is happening. You start the motors and then provide stable non-centered sticks. The controller has been instructed to enter failsafe when this happens (you chose that in the settings) and part of failsafe is to first achieve a predetermined altitude. So, off it goes. All is working precisely as planned. There is nothing to fix apart from behavior.

 

[tahoejmfc]

I mentioned in the group build we're doing that the LED Indications page should be printed out in color (and probably laminated) and referred to regularly while out flying so that the indications can be accurately understood. It probably would have helped Mike Mas out if he had done that.

Bart

Mike must know about the LED codes, he wrote a 22 page write up on how to use the copter, included in this write up, is a complete color chart that Mike has added and must have looked over, wait, maybe he did not read it and just regurgitated info and copy and pasted screen grabs into the article.

Recalibrate, center your sticks, check your end points, turn off the failsafe feature you should not be using until your copter is initially programmed correctly and flying

 

[Bartman]

that last part is a good point tahoejmfc, new flyers might think that they will benefit from advanced features that might save them if they do something wrong but NEW BUILDERS will be hard pressed to get the advanced features set up correctly from the beginning and might just make their initial success even harder to come by.

the moral of the story is, do what you can and keep things as simple as possible. if at any time you don't feel comfortable with what you're doing, stop and find help whether it's a place like this or the shop that sold you your gear.

the blinking amber lights should have definitely told Mike his heli had a problem before he walked away from it to do something else.

 

[Mike Mas]

I didn't start the thread looking for help. I'm well aware of what the problem is. I happen to have no less than 6 Naza equipped machines. I'm more than familiar with stick centering and the reaction thereof – this was never the point of the post.

I started the thread for the sole purpose of safety reasons, to make others aware this was a unknown potential danger and a safety issue that no one has addressed.
Regardless of how negative some of you guys have been to this alert - no one in this industry is going to prove to me that there is any reason a the RAP to be reactive while the machine is on the ground and cause an unexpected lift off that could injure others.

I repeat – the simple fix to avoid a possible injury is for DJI to use the same firmware routine they use for Home & Heading lock - once the machine is on the ground or if its closer than 10 meters from the home point, the RAP feature & failsafe is disabled.

No one needs the machine to climb to 60 feet then re-land when it on the ground already!!!