[Canberrauav] results from today
Andrew Tridgell tridge at samba.org 
Sun May 11 19:01:00 EST 2014 

Hi All,

Steve, Jack and I flew the bushmaster at CMAC today. The main aims were
to tune with the digital airspeed sensor and get the ground steering
tuned for auto-takeoff.

Fitting the airspeed sensor went well, although we noticed a
considerable amount of sensor noise with the engine running, looking
very similar to what we initially saw on the Porter. I went home to
fetch some ferrite clamps, which is what helped with the Porter, and
after that the airspeed was much cleaner, and performed well. I think it
would be worth incorporating one or more of the clamps into the I2C
cable in the wing. 

We enabled airspeed autocal and did an auto mission. The airspeed ratio
settled in at about 2.1, which indicates a good install.

Landings in FBWA were very smooth, and overall the plane flew very nicely.

The ground steering tuning also went well, with it getting quite close
after a couple of tries. We then did a full auto takeoff which went fine
with only a small amount of heading drift (not enough to be a problem).

Jack and I then did a bit more flying, with only one scary moment when
the EKF AHRS system diverged badly so the plane lost its attitude
estimate. We switched to manual, then I disabled the EKF and we
continued the flight. I have since analysed the flight log with Paul
Riseborough and determined that the issue is one which Paul had already
addressed in some pending patches. I have now pushed those patches to
master.

The only other issue today was losing a nut off the hinge bolt for the
rear part of the fuselage (Jack replaced it), and a noticible vibration
noise coming from one wing. 

Overall a very good day with 34 minutes of flight for the Bushmaster. We
hope to have the larger fuel tanks installed for next weekend to start
to get our hours up.

Cheers, Tridge

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