Before TECS if the plane gain or loss altitude in FBWA in maximum bank angle, we simply adjust the pitch_comp parameter. I have used the default TECS parameter with my Skywalker 1880 without issue but today when I set up my new Skywalker 2014, it loss altitude, about 1 meter per second when in FBWA mode. ( I have trim it for straight and level at 50% throttle in manual mode )
Please let me know what parameter should I adjust ?
Thanks
I posted a similar question awhile back. No answer from developers yet. I subtly lose altitude when in FBWA.
No one have any idea about this? or it is too simple or no one but myself and Steven experience this problem?
FBWA is an angle control mode, not a height control mode. Adjust AHRS_TRIM_Y (in radians) to change the trim angle.
[quote=“tridge”]The parameter you need to look at is PTCH2SRV_RLL
See this documentation
Cheers, Tridge[/quote]
Hi Tridge,
Good to hear from you again.
I’m aware of that parameter but I thought it was to maintain altitude in turns. My problem is that I trim out for straight and level in manual control, then switch to FBWA and there is a gradual increase in altitude. Is there any parameter that can compensate for this effect?
Thanks,
Steven
[quote=“Steven G”] My problem is that I trim out for straight and level in manual control, then switch to FBWA and there is a gradual increase in altitude. Is there any parameter that can compensate for this effect?
[/quote]
my apologies, I’d misunderstood your question.
The altitude change in FBWA depends on two things:
[ul]what speed you fly at
what pitch you fly at
[/ul]
The speed is totally under pilot control. If you push the throttle up then it will fly faster, and it will climb (more speed == more lift).
What you can do is adjust the zero pitch angle that APM uses when in FBWA mode. You can adjust that using the TRIM_PITCH_CD parameter. Adjust it in small increments, maybe 1 degree at a time (it is in centi-degrees). Don’t go past about 5 degrees.
It would be even better to use a height controlled mode, such as FBWB or CRUISE mode. I’d recommend CRUISE mode, perhaps with FBWB_CLIMB_RATE set a bit higher than the default to give you faster height control.
Cheers, Tridge
Ok. I will try your suggestions. I really like the FBWA mode for manual control with stability. But watch out if you get in a stall!! Switch to manual ASAP or you will be in dig it out of the ground mode. 