I seem to be having a problem with the airspeed indicator. I have read through ALL the pages related to this and just cant get it right. Here is the problem :
On my Skywalker, I have the airspeed indicator installed in front of the nose. THe pitot tube us the new one from 3DR ( which combines the actions/passive tubes ) . The tube extends about 2" past fuse and the side holes on the tube are out in the open.
The airspeed indicator is properly calibrated . When i blow into the tube, the airspeed rises.
When lying still, the airspeed fluctuates between 1-3 and sometimes goes to 4. This is supposed to be normal, per the manuals.
The problem is - when flying, reported airspeed is much less than what I feel it should be. This is based on flying on a very calm day, and noting the difference in AS and GS to be more than 15 km/hr ( AS is less ) .
I tried to circle etc but the difference was there in all directions.
I am using APM 2.75 . ON another plane, I have the airspeed indicator with the old pitot tubes and i flew it on the same day and it was spot on.
Do you think its an issue with the sensor hardware, tubing, pitot tubes etc ? or something I can fix with software / tuning etc.