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Does ATTI mode hold altitude with sticks released?

Discussion in 'General Discussion' started by BlackTracer, Sep 15, 2014.

  1. BlackTracer

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    I say no but I have read vague documentation that it does as well as have had others try to tell me yes it does.

    The fact that it loses altitude with steep forward pitch applied kind of proves it to me.

    Has anyone let it drift with the wind and noticed if the altitude can and does change?

    I want to get this answered once and for all.
     
  2. rrmccabe

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    It should maintain altitude but not location. I have not tested with steep pitch as you have mentioned but I have flipped to ATTI and let it drift over 1/2 mile while filming in 10 mile wind and the elevation stayed right on.
     
  3. N017RW

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    There will be some slight loss in fast forward flight as the control is aggravated by additional drag of the tilted the shell.

    To help minimize it: make sure your a/c is well balanced, verify the sticks are properly calibrated at the Tx and then the Naza (centering is important), Raise your Vertical gain in the manner described for gain adjustments.
     
  4. rrmccabe

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    Will it ever regain back to the point of elevation at time when you switched to ATTI mode? Apparently it has the ability to maintain elevation in hover state but if you dive down and lose elevation it wont try to make it up?
     
  5. rrmccabe

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    Thanks for update !

    The way the wind is blowing her today if I flipping it to ATTI it might end up in the next state north :(
     
  6. rrmccabe

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    I believe that is "known driftaway" :mrgreen:
     
  7. BlackTracer

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    I wonder what would happen if you brought it right in front of you within grabbing distance, grab it and pull it down a few feet (simulating a downdraft). Would it correct to the original altitude or stay where you dragged it to?
     
  8. N017RW

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    I have done this as well as change location by a few feet, and add yaw, it will attempt to return to exact position.

    My stab at another discussion point...

    Unlike above where outside influence(s) changed the a/c's attitude, and since the altitude 'drift' is occurring during stick input(s) like forward flight, upon release of sticks or their return to center the a/c will see that attitude as the 'new' attitude to maintain thus it will not try to recover or compensate for any altitude drift as it 'sees' no need to.
     
  9. Happyflyer

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    :lol: :lol: :lol: :lol: :lol:
     
  10. Damon

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    I have noticed changes in actual altitude when flying over rolling hills especially over the lower drawls. As they are normally cooler. When flying over level terrain the P2 in ATTI stays level even in full speed run.

    Quick Google of barometer over terrain netted this.

    "The accuracy of aircraft altimeters is subject to the following factors:

    1.Nonstandard temperatures of the atmosphere.

    2.Nonstandard atmospheric pressure.

    3.Aircraft static pressure systems (position error); and

    4.Instrument error.

    b.EXTREME CAUTION SHOULD BE EXERCISED WHEN FLYING IN PROXIMITY TO OBSTRUCTIONS OR TERRAIN IN LOW TEMPERATURES AND PRESSURES. This is especially true in extremely cold temperatures that cause a large differential between the Standard Day temperature and actual temperature. This circumstance can cause serious errors that result in the aircraft being significantly lower than the indicated altitude."