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View Full Version : how the TruTrak would do in unusual attitudes...


n468ac
12-01-2008, 08:11 AM
I did some flight testing this weekend to find out how the TruTrak DigiFlight II VSGV (http://www.trutrakflightsystems.com/instruments_digiflight_2_VSGV.htm) would do in unusual attitudes.
The test is simple? roll 45, 60, 70, 80, 90, 100, 110, 120, 125, 130, 135 Deg and pitch 10, 20, 30, 40, 50, 60, 70 Deg up (didn?t test down pitch as the roll testing showed the autopilot didn?t recover in 30 deg nose down attitudes) and let go of the stick, engage the autopilot
Goal ? to see how far the DigiFlight II VSGV (http://www.trutrakflightsystems.com/instruments_digiflight_2_VSGV.htm) could go into unusual attitudes and recover the airplane for you.
The result ? the DigiFlight II VSGV (http://www.trutrakflightsystems.com/instruments_digiflight_2_VSGV.htm) could recover a roll and pitch combo up to 60 deg in both directions at the same time. It could recover the roll up to 120 deg but not the pitch, even with the trim set full up before entering the roll the autopilot could not recover the pitch. Beyond the 120 degs the auto pilot couldn?t recover the roll as it didn?t have enough power in the servo to pull the plane back to level. The other interesting thing is the autopilot would always go back ? it wouldn?t continue the roll; it always rolled back the direction the roll came from.

AntiGravity
12-01-2008, 10:51 AM
Are you saying it could recover up to 60- degrees of pitch and up to 60 degrees of roll? At the same time?

But that it could recover up to 120 degrees of roll, but not pitch (of any amount) at the same time?

Does that mean that if you were pitched down 60 degrees with a roll of up to 120 degrees then it would recover ok?

Thanks for doing the testing; interesting stuff.

n468ac
12-01-2008, 11:17 AM
Are you saying it could recover up to 60- degrees of pitch and up to 60 degrees of roll? At the same time?

Yes, but pitch must be up, in down over 10 degs it would not recover.


But that it could recover up to 120 degrees of roll, but not pitch (of any amount) at the same time?

Yes


Does that mean that if you were pitched down 60 degrees with a roll of up to 120 degrees then it would recover ok?

No, it could not recover pitch over 10 deg nose down with a bank angle above about 40 degs. Your speed climbs to quickly and over powers to the autopilot.


Thanks for doing the testing; interesting stuff.

Thanks,

AntiGravity
12-01-2008, 03:11 PM
...enable the auto-pilot *before* you get in trouble, and...

...if you're already in trouble don't believe the auto-pilot will necessarily save your a**!

Cheers.