Compass Calibration Issue

[tweaker]

Had a funny one today....

Flew all day. Rotating and charging batteries and only stopping for lunch.

Had high compass readings toward end of the day.

Near the end of the day I had to (3 times one after the other) recalibrate compass as reading was 1650-1700 ish as I did my pre flight checks before take off.

This happened after I landed,changed lens and inserted fresh battery on all three occasions.

Thoughts?

 

[The Editor]

Had a funny one today....

Flew all day. Rotating and charging batteries and only stopping for lunch.

Had high compass readings toward end of the day.

Near the end of the day I had to (3 times one after the other) recalibrate compass as reading was 1650-1700 ish as I did my pre flight checks before take off.

This happened after I landed,changed lens and inserted fresh battery on all three occasions.

Thoughts?

Difficult to say without seeing the problem.
On each occasion when you calibrated did the mod values come back down again? If so, was it just for that flight?
Where a bouts were you flying? If you don't want to say on open forum PM me the Long/Lat and I will take a look.
Did you get a "Compass Error" message at any point during these high(ish) readings?
There are a couple of places I fly where I get readings of over 1600 when the Inspire is on the ground but I never recalibrate because I know I have a good calibration and once I take off everything is fine.

 

[tweaker]

Re calibrated compass reading came back down to acceptable parameters.

Yes had a compass error when airborne once. Took her down checked sensors -all good.

Yes I never normally re calibrate unless my readings are off just check sensors as part of pre flight checks,changing batts etc

Travelled about 150 miles from base location for this job.

Filming up and down a river in a rural location.

Take off point was from a wide private bridge.

Happy to share above on open forum as hopefully others may chime in or inform them if they happen to have same problem.

 

[tweaker]

Oh forgot to say on one take off informed me it was in atti mode when it was not on one occasion (Had gps lock before take off).

Approx 5-10 secs after informing me it was in atti it reverted to gps lock again.

No obstructions above/to the side within about 100-150 m radius.

 

[The Editor]

Ahh, could that bridge have large amounts of metal in it by any chance?
If you were landing and taking off from that structure and it had a high ferrous content your compass may have been affected over time.
You should not see this anomaly again. I regularly fly around 8 batteries one after the other and have not had any compass drift issues.

 

[tweaker]

Yep only thing I could think of.

Just wanted to throw it out there share and learn if others had found similar.

Thanks for heads up.

 

[The Editor]

Yep only thing I could think of.

Just wanted to throw it out there share and learn if others had found similar.

Thanks for heads up.

The dropping into P-Atti issue would be because of the compass issue.
The compass algorithms were rewritten a while back to try and stop the aircraft going into TBE if there was a compass error. It was considered more favourable and safer for the Inspire to drop into P-Atti if there was a compass error rather than the operator try and battle with TBE and the aircraft stay in P-GPS.

 

[tweaker]

Agree with Atti being more favourable than TBE.

Had that happen aggresively ONCE- not pleasant!

Good for a blood pressure and heart work out though!!