Control Wheel Movement-Aerobat

Discussion in 'Aerobatics' started by etemplet, Mar 6, 2016.

  1. etemplet

    etemplet Pre-takeoff checklist

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    This may sound silly but.... Some discussion on the range of movement for my Aerobat control wheel has arisen. On My plane, Delmar, my wheel moves 90 degrees left and right to full aileron lock. Others have stated their planes (Aerobats) move 180 degrees (fully upside down) to full aileron lock. Any thoughts. I can't find anything definitive on control position, only the degree of aileron deflection up and down. It says nothing about control wheel position.
     
  2. Greg Bockelman

    Greg Bockelman Administrator Management Council Member

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    180 is excessive. You sure there isn't a misunderstanding of terms? Your 90 from neutral to stop Vs their 180 from stop to stop?
     
  3. etemplet

    etemplet Pre-takeoff checklist

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    People are telling me their planes and ones they have flown, the control wheel is completely upside down at full aileron. That is the tip of the iceberg. There is even claim that Aerobats control wheel have a greater range of motion. So much for the Cessna 152/152 Forum. I figured I'm come here and ask the question. A friend of mine checked aileron rigging specs and it did not say anything about range of control wheel movement but only gives the degree of movement as measured at the ailerons, which seems to be the logical way to measure to me.

    This all started when I said my control wheel movement is 90 degrees left and right, which is how mine works. I checked other 150s and other owners have checked theirs. Their range if movement is closer to the range on Delmar (my plane). BAsically I have a full 180 degrees of movement stop to stop. What others imply is there full range is 360 degrees stop to stop. That would imply there are different parts in the aircraft but I a not going there. LOL
     
  4. etemplet

    etemplet Pre-takeoff checklist

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    From my research and responses from knowledgeable people it seems that 90 degrees each side is normal.
     
  5. denverpilot

    denverpilot Taxi to Parking

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    Should be approximately 90. I suspect @Greg Bockelman has the reason why the confusion.
     
  6. Dan Thomas

    Dan Thomas En-Route

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    The wheel movement is governed by the size of the sprocket at the other end of the control wheel shaft and the length of the aileron bellcrank arms. That sprocket is already pretty small, so to get more movement you'd need much bigger bellcranks, which I have never seen in any Cessna and which there's no room for anyway. They'd collide with the false spar.

    Much more likely is a bunch of slop in a badly worn-out system with cables well below tension specs.
     
  7. denverpilot

    denverpilot Taxi to Parking

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    An extra 90 degrees (!) would be so much slop I would think the cables would have fallen off the bellcranks.

    No way unless you were not paying even a single bit of attention that you'd miss that much slop during a preflight when you checked the ailerons for play and hinge condition.
     
  8. etemplet

    etemplet Pre-takeoff checklist

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    Well when in doubt I come to you guys for certain. I am getting arguments on the 150 forum about this but I have not entered into any argument nor will I. All I posted was that when rolling my plane left the control wheel stops at 90 degrees. I surly thank you all for your consistent help and support for this rookie Aerobat pilot. LOL :) I will be asking more questions as I work on maneuvers.
     
  9. Stewartb

    Stewartb En-Route

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    Control ranges are no different in aerobatic or std 150 models. A difference in yoke range is unlikely. Besides, to rotate a yoke past 90* would be very awkward.

    http://rgl.faa.gov/Regulatory_and_G...9938e5586257ed2006b5117/$FILE/3A19_Rev_49.pdf

    Note the revision date. All of Cessna's TCDSs are now registered to Textron Aviation. The only ones in the Cessna name are the old Reims models. That's the first time I noticed.
     
  10. etemplet

    etemplet Pre-takeoff checklist

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    Thanks Stewartb. I often where people get some of their dis-information. I was about to call Cessna but I guess my plane is safe to fly. LOL
     
  11. Dan Thomas

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    I have seen some sad stuff in my work. Cables don't fall off bellcranks and very seldom off pulleys unless the guard pins have been left out. The system is designed to handle momentary slack.

    One other possibility is the absence of the stop bolts and spacers at the bellcranks in the wing. That would leave the ailerons free to move down until the forward lower edge hits the false spar, and up until the pushrod is jammed against the bottom aileron skin and spar.

    Right now we have an airplane in here whose aileron cables are at double the specified tension, and the flaps are well above the upper limit, too. The trim has been rigged with the travel limits reversed and the jackscrew thread is close to departing the nut. That would cause tab flutter and probable airframe failure. The elevator travels are way off.

    Some of the stuff we find is completely appalling. We regularly find all five flight control systems way out of rig (aileron, elevator, rudder, flaps and trim).
     
    Last edited: Mar 7, 2016
  12. djpacro

    djpacro Pre-Flight

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    Some years ago I taught aerobatics in 150 and 152 Aerobats. Very occasionally I would observe a student get the yoke all the way round to about 180 deg while doing a roll. Afterwards on the ground I would get him to give it full aileron deflection and then discuss - 90 deg gets full aileron deflection.
    I'd never bothered with an engineering assessment - I'd guess the control stops are out near the ailerons.
     
  13. Dan Thomas

    Dan Thomas En-Route

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    They are. Built into the bellcranks that drive the push-pull rods to the ailerons themselves. Sounds like the cable tensions are low. Have also seen bent/broken structure in the belly at the aft doorpost caused by overtight cables, and it can flex and cause slop. The aileron cables pass over pulleys in that bulkhead, changing direction from straight back to sideways out to the doorposts, around more pulleys and up the posts to further pulleys and outward inside the wing.
     
  14. djpacro

    djpacro Pre-Flight

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    Saw a 152 recently so turned the yoke to 90 deg and got full deflection then found that applying more pressure would turn the yoke more with nil change in aileron deflection.
     
  15. James331

    James331 Touchdown! Greaser!

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    I would 180 degree deflection would be quite awkward to fly with, especially in a aerobatic plane.

    If I stepped foot in one of those guys aerobats for a BFR or something and on "free and correct" he 180ed the yoke, that would be the end of the flight until it had a proper going over and fix by a AP, or he should show me where it states 180* movement was acceptable

    Your 90 degrees sounds like how the plane SHOULD be.
     
  16. Stearman

    Stearman Pre-takeoff checklist

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    I can't imagine getting the yoke 180° around given where my knees are, much less trying to fly it like that.
     
  17. coloradobluesky

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    Thats so you can fly it upsidedown! :)
     
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