Yeah, I know but it gave me a good laugh and had to share.
OMG, LOL, I can't stop laughing,
Rod
Sent from my HTC 10 using PhantomPilots mobile app
Had an accident need input
- Thread starter Roccot312
- Start date
Sent from my HTC 10 using PhantomPilots mobile app
- Joined
- Jul 24, 2016
- Messages
- 64
- Reaction score
- 14
- Age
- 40
Ok so it seems to have been a compass error/yaw error. Due to reinforced concrete that's what I'm going to go with....
now my question is what should my compass readings be between ? when I checked the settings before I took off the compass readings were in the1600s and on most flights when I check it I'm In the 1400s, I'm guessing this could give me a good idea weather I'm going to have a compass error or not before taking off.
I just want to minimize any risk before I take off so that I can have a safe flight
Sent from my 831C using PhantomPilots mobile app
now my question is what should my compass readings be between ? when I checked the settings before I took off the compass readings were in the1600s and on most flights when I check it I'm In the 1400s, I'm guessing this could give me a good idea weather I'm going to have a compass error or not before taking off.
I just want to minimize any risk before I take off so that I can have a safe flight
Sent from my 831C using PhantomPilots mobile app
From your description and the .txt I suspect your incident was due to what was described in
Looking for Trouble ??
It's difficult to see this will happen before you launch the AC. The problem is that the geomagnetic field is distorted but it's strength is only slightly different. The magMod value you see is the geomagnetic field strength.
The best thing you can do is not launch from locations that might have ferrous material. If you have to, then hand launch it as high as you can. The effects of the rebar probably aren't strong enough at 2 meters to cause a problem.
The other thing you can do is prior to launch check that AC triangle icon in the radar display in the Go App is pointed correctly. You'll have to eyeball the AC and know what it's heading is. Then see if the triangle icon is pointing the same direction. Having suggested this let me add that I never do this.
If you want to know more about the cause of the incident you'll need to provide the .DAT for the flight. Look here to see how to retrieve the .DAT. It's too large to attach to a post so you'll need to Dropbox it.
Last edited:
I guess I have been quite lucky. I frequently launch from my back yard (tiled concrete, not a garden). It is full of rebar (rhubarb!) and the craft will not launch from the floor; the Go! app reports a compass error. By simply putting it on a plastic table though, it takes off and flies just fine, and I can land on the floor if I can't be bothered landing on the plastic table.
Have I been lucky or is 3' indeed sufficient to reduce the effects of the iron to negligible?
Have I been lucky or is 3' indeed sufficient to reduce the effects of the iron to negligible?
The extent of the geomagnetic distortion depends on the mass, density, composition, etc. of the rebar. But, it seems in your situation that 3' is enough.
Thanks Bud, that was my initial thought. It was reading this and other similar threads that got me thinking, worrying.
I don't make a habit of calibrating the compass, in fact I can't even remember where I last did it. Wherever it was done (and it may have been in the yard) it seems to be OK too.
If it ain't broke etc. etc....
I was about to add something to my post. You might be lucky. Sitting on the concrete the effects are strong enough to cause magMod (which measures field strength) limits to be exceeded and the Go App declares a compass error. At 3' it seems there isn't enough distortion to cause a problem. There may be a zone between 0 and 3' where the field is distorted but magMod is within limits.
Yeah, I don't calibrate the compass. Except when I'm doing some experiment. The reason for recalibrating at a new location is because the geomagnetic field strength could be different. Has nothing to do with the geomagnetic declination.
I suspect that you are correct that compass calibration is now only to account for field distortion (deviation) due to the aircraft components themselves, while declination and inclination are mapped in the FC firmware. Hence, in general, there is no need to recalibrate even when moving between regions with different declination/inclination.
That was not always the case though - the early NAZA controllers did not, it appeared, have maps of the earth's magnetic field, and so calibration back then was for both effects.
It's also possible that declination is computed.
I'm not familiar with the compass calibration procedure of those early NAZA controllers. But, if it's like the compass dance for the P3 then declination can't be determined from that dance. That would require the AC be stationary and then told what the true heading (not magnetic heading) is. In essence it would have to be told what the declination is.
RodPad
Premium Pilot
I just did a cold IMU, it is 28 F deg, and I'm tired of waiting for it warm up, set it outside 1/2 hr prior, the question is, would you, should you calibrate the compass?
Rod
Rod
You are quite correct - the old method was very similar and could not, on its own, determine declination, although it could determine inclination. The early NAZA P2 FCs appeared to refine declination on the fly, presumably by comparing magnetic heading with GPS track, which led to some erratic initial course behavior and the dreaded J-hook flight path.
Similar threads
