Bummed. New P3A Crashed. Pls Advise

craigsdal · Nov 18, 2015

That was my first thought, battery not engaged 100%...bummer.

III% Streve · Nov 18, 2015

craigsdal said:
That was my first thought, battery not engaged 100%...bummer.

As far as crashes that I have been part of investigating, there has never been a P3 come down because the battery fell out. Not saying it hasnt happened. Just that I have never seen one. Coudnt care less about P2 issue.

TheRealNick · Nov 18, 2015

III% Streve said:
Compass issue tend to lead to an uncontrolled, ever increasing and accelerating, spiral that usually flies away to a point where it looses contact.

If you put it in ATTI mode does it ignore the compass?

III% Streve · Nov 18, 2015

TheRealNick said:
If you put it in ATTI mode does it ignore the compass?

It is thought that this could be an "easy" way to recover control from a compass failure/fly away. But it hasn't been documented as successful yet. Hard to really know unless a crash is barely saved.

syotr · Nov 19, 2015

TheRealNick said:
If you put it in ATTI mode does it ignore the compass?

ATTI mode does use the compass.

TheRealNick · Nov 19, 2015

syotr said:
ATTI mode does use the compass.

Is there a mode that doesn't? I have been flying a few non-gps drones (no compass either), and I figured worse case with Phantom is this kind of flight, but if it spins out of control no matter what seems like there is no way to recover...

It sounds like you have to rely on the Phantom figuring out there is a compass error....

syotr · Nov 19, 2015

Many flyaways involve some confusion between the compass and GPS that the flight controller cannot resolve. Switching to ATTI mode ignores the GPS. This can save a flyaway sometimes. It has worked once for me. You can switch to full manual mode but this takes a lot of practice to fly.
I know that the NAZA controller will work fine without GPS or compass. If you buy the stand-alone NAZA controller, it comes without either and works fine in ATTI mode. The GPS module for the stand-alone NAZA has the compass inside. The Phantom has the compass mounted separately on the landing gear leg.

TheRealNick · Nov 19, 2015

syotr said:
Many flyaways involve some confusion between the compass and GPS that the flight controller cannot resolve. Switching to ATTI mode ignores the GPS. This can save a flyaway sometimes. It has worked once for me. You can switch to full manual mode but this takes a lot of practice to fly.
I know that the NAZA controller will work fine without GPS or compass. If you buy the stand-alone NAZA controller, it comes without either and works fine in ATTI mode. The GPS module for the stand-alone NAZA has the compass inside. The Phantom has the compass mounted separately on the landing gear leg.

How do you switch to full manual mode? I have not seen that reading through the manual's...I plan to buy an advanced hopefully at a great price next week! I have great fear of crash...

syotr · Nov 19, 2015

Dounin Front said:
How do we know that? Just wondering where where you got that info.

This has been discussed in other forums but one obvious clue is that Course Lock requires the compass and works in ATTI mode when GPS is not available or switched off.

syotr · Nov 19, 2015

TheRealNick said:
How do you switch to full manual mode? I have not seen that reading through the manual's...I plan to buy an advanced hopefully at a great price next week! I have great fear of crash...

I only have the P1 so I can't answer for P3 but on P1 it is an option for the lowest position for the s1 switch and has to be turned on in the NAZA assistant.

Meta4 · Nov 19, 2015

TheRealNick said:
How do you switch to full manual mode? I have not seen that reading through the manual's.
... I have great fear of crash...

There is no manual mode on the P3. There was on earlier models.
Stay away from trees and buildings, read and understand the manual and you've just about eliminated the chance of crashing a P3.

syotr · Nov 19, 2015

Meta4 said:
Stay away from trees and buildings, read and understand the manual and you've just about eliminated the chance of crashing a P3.

That's just funny

BudWalker · Nov 19, 2015

syotr said:
This has been discussed in other forums but one obvious clue is that Course Lock requires the compass and works in ATTI mode when GPS is not available or switched off.

Can you point me to where this has been discussed?

TheRealNick · Nov 19, 2015

I think it needs GPS for all the intelligent flight modes, check this link:

New Phantom 3 and Inspire 1 Intelligent Flight Modes | DJI

I find it very humorous that it shows a picture of someone skiing for follow me mode and then at the bottom says:

Note: Intelligent Flight Modes are only available when sufficient GPS signal is available. Always fly safely and with your hands on the controller at all times, even when using these automatic functions.

How are you skiing while also keeping hands on the controller....I believe it follows the phone, so perhaps you could separate the two while using this feature, except, I think the phone has to be plugged into the controller right....so in the example the skiing has to have the transmitter and phone with them and also in such a way that the sticks and phone are not bumped....

syotr · Nov 19, 2015

BudWalker said:
Can you point me to where this has been discussed?

It has been a while ago and in discussions about P1 and P2. P3 may be different. If I remember correctly, my understanding was that the compass is used in ATTI mode if it is detected.
Not sure what happens if the compass is giving bad readings.
It is obvious that the compass is used in Course Lock and this works in ATTI mode. If you are in Home Lock mode and lose satellites, it switches to Course Lock mode automatically.I will search to see if I can find the discussions. DJI does not spell this out clearly.

SCADAMON · Nov 19, 2015

Gravity was in full effect, this is for sure...

Luap · Dec 1, 2015

TheRealNick said:
View attachment 35852

In the above picture I paused the playback right at the start of the decent. You can see in the middle picture the phantom banked hard right. In the left picture you can see the phantom nose went down. This matches loss of lift on the front right corner, which matches the corner that had the only intact prop found detached.

From the video in post 140 it is pretty hard to make the props come off and McVentures said he did finger tight. I think if the torque was that critical we would see this all the time. I think something caused that motor to stop. Maybe not motor failure, a logic or esc fault perhaps, who knows...

Bringing back an old post but tested the new DAT converter with motor RPM data :
New version of .DAT converter | DJI Phantom Forum
Below video made in Dashware including RPM charts for each motor.
If you look at the motor RPM Right Front Chart you will see RPM go up to 10000 just prior altitude loss.

Thats the prop flying off.
Here a static test I made to check max rpm at no load (no props).

syotr · Dec 1, 2015

That's cool. I wonder if the RPM is actually measured or if that is calculated based on a command sent from the flight controller.

TheRealNick · Dec 1, 2015

syotr said:
That's cool. I wonder if the RPM is actually measured or if that is calculated based on a command sent from the flight controller.

The data to me looks like commanded because at the start the RPM numbers are exactly the same for all 4 motors.

BudWalker · Dec 1, 2015

syotr said:
That's cool. I wonder if the RPM is actually measured or if that is calculated based on a command sent from the flight controller.

I'm almost sure that the motor speed data is commanded and not actual. Also, 10,000 isn't necessarily 10,000 RPM. It's just the max value. I.e. there is probably some constant such that RPM = constant X measured value.