Weird flight... Could use some advice

[BudWalker]

The DropBox link for Ben's FLY046 is
Dropbox - FLY046.DAT
I wont get chance to look at this until later today. But, others are certainly welcomed to take a look.

@Luap, @TheRealNick, @JustJ

 

[Benjamin B.]

I just re-calibrated in the closest area that I have to an empty field (construction site where the roads aren't paved yet.) Took it on a much, much shorter flight but did similar turns at speed and had zero issues. MOD value for the compass was around 1540.

 

[Benjamin B.]

The DropBox link for Ben's FLY046 is
Dropbox - FLY046.DAT
I wont get chance to look at this until later today. But, others are certainly welcomed to take a look.

@Luap, @TheRealNick, @JustJ

Thanks for posting this Bud.

 

[Luap]

Thanks for posting this Bud.

I can see pretty much what happened from the DAT file but could you also post the txt log? The same one you uploaded to Healthydrones.

 

[Benjamin B.]

I can see pretty much what happened from the DAT file but could you also post the txt log? The same one you uploaded to Healthydrones.

Sent you a direct message with a link to the .txt file. Thanks for your help!

 

[Benjamin B.]

Yeah that crazy because you only show wind gusts of 14 MPH, I've flown in pretty high wind, like 40 and would hit like 47 MPH with a tail wind. Hey you may have a photo type model with a turbo [emoji15]LOL

Doesn't everyone have that extra "Nitro" button on their controller? lol

 

[Luap]

You can see the motors RPM (the yellow line in motors graph) go up during/after the 180 turn. Also amps/watts go up.
You apply yaw (quite a lot at one point) on the RC with a lot of forward pitch to do that curve but no roll. I would recommend for fast curves to use some roll as well.
The speed goes up to 90kmh just after the curve so shows must have been a gust. After it goes to around 50kmh with same forward pitch - see thumbnail.
I do did not see anything abnormal in compass values.
I would deduct this is result of applying too much yaw with forward pitch in the curve combined with a strong gust which made the P3 work harder to keep its balance.

 

[Benjamin B.]

Thanks so much for the analysis! So the compass error and "switch to ATTI mode" that I was getting was more than likely a result of turning too sharply while pitched too far forward?


Sent from my iPhone using PhantomPilots mobile app

 

[Wibble]

If you don't move more than 100 miles from the last compass calibration it's best not to recalibrate. Stick with a field calibration that works for you. If you have an issue with compass, recalibrate and leave it alone unless you have an issue.

I've recently had the same issue about 30 seconds into my 3rd flight from the same spot. Unexplainable.

I agree only calibrated the once and it is fine touch wood!

 

[BudWalker]

Thanks so much for the analysis! So the compass error and "switch to ATTI mode" that I was getting was more than likely a result of turning too sharply while pitched too far forward?


Sent from my iPhone using PhantomPilots mobile app

You're probably wondering how can a compass error and switch to ATTI mode be caused by unusual, but not very unusual, flight operations. I have a theory/opinion about that but we need to look at some previous flights that we've analyzed. It'll be a couple of days. The short answer is that it's not a "compass error" like the compass produced incorrect data. Rather, the flight controller detects a disagreement between actual sensor data and what it thinks the sensor data should be.

 

[Benjamin B.]

You're probably wondering how can a compass error and switch to ATTI mode be caused by unusual, but not very unusual, flight operations. I have a theory/opinion about that but we need to look at some previous flights that we've analyzed. It'll be a couple of days. The short answer is that it's not a "compass error" like the compass produced incorrect data. Rather, the flight controller detects a disagreement between actual sensor data and what it thinks the sensor data should be.

Thanks Bud. That is indeed the heart of my concern. Would you like me to send you the link to the .txt file as well? Not sure if that would assist or not. I appreciate the help from everyone!

 

[BudWalker]

Thanks Bud. That is indeed the heart of my concern. Would you like me to send you the link to the .txt file as well? Not sure if that would assist or not. I appreciate the help from everyone!

Thanks, but the .txt won't help. It's all in the .DAT.

I should've added to the short version that gusty, or high wind conditions can cause this. That seems to have been the case here. The P3 did exactly what it should've; switch to ATT and let the pilot deal with it. I wouldn't worry as this was an unusual situation.

BTW, did you see "Compass Error" on the GO app but it doesn't seem to show up in a replay of the flight? I had exactly that in a flight I did. I'm absolutely sure I saw it, but can't find it in the replay.

 

[Benjamin B.]

Thanks, but the .txt won't help. It's all in the .DAT.

I should've added to the short version that gusty, or high wind conditions can cause this. That seems to have been the case here. The P3 did exactly what it should've; switch to ATT and let the pilot deal with it. I wouldn't worry as this was an unusual situation.

BTW, did you see "Compass Error" on the GO app but it doesn't seem to show up in a replay of the flight? I had exactly that in a flight I did. I'm absolutely sure I saw it, but can't find it in the replay.

Absolutely Bud. I saw "Compass Error, switch to ATTI mode" flashing across my display. That is what caused my brief panic... I know how fatal the compass errors can be. I corrected the horizon through FPV and then went to switch to ATTI. To note, I didn't successfully switch to ATTI - I accidentally toggled all of the way to F mode, and then back to P. Doing that cleared the issue.

 

[BudWalker]

Absolutely Bud. I saw "Compass Error, switch to ATTI mode" flashing across my display. That is what caused my brief panic... I know how fatal the compass errors can be. I corrected the horizon through FPV and then went to switch to ATTI. To note, I didn't successfully switch to ATTI - I accidentally toggled all of the way to F mode, and then back to P. Doing that cleared the issue.

Could it have switched back to GPS-ATTI on it's own and that was just coincident with you toggling the P-A-F switch? I count 9 times it switched between ATTI and GPS_ATTI in the interval 511.018 seconds to 537.238 seconds

 

[Benjamin B.]

Could it have switched back to GPS-ATTI on it's own and that was just coincident with you toggling the P-A-F switch? I count 9 times it switched between ATTI and GPS_ATTI in the interval 511.018 seconds to 537.238 seconds

I suppose that is possible, but it literally stopped yelling "ATTI Mode, ATTI mode, ATTI mode" through my iPhone speaker the moment I toggled the switch to F.

 

[BudWalker]

I suppose that is possible, but it literally stopped yelling "ATTI Mode, ATTI mode, ATTI mode" through my iPhone speaker the moment I toggled the switch to F.

The red is the P3 switching between ATTI and GPS_ATTI. The blue is when you switched to F and and then back to P about a second later.

 

[Danielmexortega]

I thought we weren't supposed to calibrate before every flight? Iam sure I've read posts regarding that.


Sent from my iPhone using PhantomPilots mobile app

 

[Benjamin B.]

Video of the flight in question - the issue starts when I turn around and lasts for about 30 seconds. Start at minute 7. Before I get railed, no I did not calibrate the compass next to the snow plow. lol

 

[happydays]

I assume you have your gimbal set to FPV mode instead of follow?

 

[Benjamin B.]

I assume you have your gimbal set to FPV mode instead of follow?

Nope - that was follow. Gives you an idea of how pitched the phantom was. If you start at the beginning of this thread you'll see that I had something quite wrong when I initiated the turn-around.