grusa
New Member
This weekend we flew to tweak the autopilot settings on our skyview system. Two pilots, two screens. We identified a number of issues:-
When we Ientered the in flight setup menu on screen 2, instead of Efis on screen one and a half screen ems on screen two, we had efis on screen one and a half screen efis on 2 - no EMS display! We tweaked the autopilot with no issues, and returned to normal mode. We then decided to experiment with switching off the screens in flight. Switching off screen 2 gave us an efis and ems on screen 1 - great. Switched 2 back on, still no problem. Now we switched off screen 1 - this disengaged the autopilot and lost all its bugs, before switching to efis and ems on 2. We switched screen one back on, displays returned to normal,but we noticed our airspeed was now indicating 83kts in cruise config, not 103 as before.
Once we decided it was the asi and not the aeroplane, we tried switching adhars - the second unit read normally, the primary unit read low.
It was my understanding that the adhars units switch automatically in the event of failure, but this did not happen. Subsequent startups default to the abnormal unit, not the good one, and there is no indication that I can see as to which unit is operating and that there is a fault or discrepancy.
The question now is what is causing the discrepancy, it may be a physical leak, blockage, etc in the pitot system, but at a software/firmware level, how should it behave? It seems too coincidental that the fault occured immediately after our experimentation, and did not go away! Have we somhow upset the calibration of the adhars? that should not be possible in flight. Why does the system not recognise the discrepancies and at least warn the pilot if not automatically change over to the good unit?
Any comments?
When we Ientered the in flight setup menu on screen 2, instead of Efis on screen one and a half screen ems on screen two, we had efis on screen one and a half screen efis on 2 - no EMS display! We tweaked the autopilot with no issues, and returned to normal mode. We then decided to experiment with switching off the screens in flight. Switching off screen 2 gave us an efis and ems on screen 1 - great. Switched 2 back on, still no problem. Now we switched off screen 1 - this disengaged the autopilot and lost all its bugs, before switching to efis and ems on 2. We switched screen one back on, displays returned to normal,but we noticed our airspeed was now indicating 83kts in cruise config, not 103 as before.
Once we decided it was the asi and not the aeroplane, we tried switching adhars - the second unit read normally, the primary unit read low.
It was my understanding that the adhars units switch automatically in the event of failure, but this did not happen. Subsequent startups default to the abnormal unit, not the good one, and there is no indication that I can see as to which unit is operating and that there is a fault or discrepancy.
The question now is what is causing the discrepancy, it may be a physical leak, blockage, etc in the pitot system, but at a software/firmware level, how should it behave? It seems too coincidental that the fault occured immediately after our experimentation, and did not go away! Have we somhow upset the calibration of the adhars? that should not be possible in flight. Why does the system not recognise the discrepancies and at least warn the pilot if not automatically change over to the good unit?
Any comments?