elevator in older(70's) 172 vs newer (90's+)

Discussion in 'Hangar Talk' started by exncsurfer, Oct 13, 2017.

  1. exncsurfer

    exncsurfer Pattern Altitude

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    I've been transitioning to an older 172. I was wondering is it normal to run out of elevator sooner, than say the newer/heavier 172's? I had a heck of a time getting the 70's one to power off stall with any flaps in. I got it to break with no flaps, but with flaps it would just kind of mush and not really give a definitive break, held full aft.

    In the newer ones I never had a problem getting a power off stall to break.

    The empty CG according to the WB numbers is actually farther aft comparatively if the paperwork is accurate. I would think that would make it easier to stall, no?
     
  2. Dan Thomas

    Dan Thomas Final Approach

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    The CG of the R and S models is indeed farther aft, so much so that it can't be brought into the utility category (for spins and such) without removing the back seat. The seats weigh about three times what the old ones did. The G1000 models are worse, IIRC. They have a lot of avionics in the tailcone.

    And the R and S have a leading edge extension that sticks up above the stab surface when at high deflections. I think it's to help keep the flow attached.

    And there's one more thing: the older an airplane gets, and the more hours it accumulates and damage that gets repaired, the farther out we find the control surface rigging. Finding elevator travels way off is not uncommon.
     
  3. mscard88

    mscard88 Touchdown! Greaser!

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    You more rudder, full rudder :D

    I kid
     
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  4. exncsurfer

    exncsurfer Pattern Altitude

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    You trying to set me up for a fun ride? Ha.
     
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  5. exncsurfer

    exncsurfer Pattern Altitude

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    Well, that is the opposite of what the paperwork is saying, which I thought was odd. I need to review the WB numbers and see if they screwed it up.

    Shouldn't a more aft CG make it easier to stall?

    Move weight aft, nose comes up, to stay level, yoke goes forward(giving you more range in the opposite direction). Move weight fore, nose drops, yoke comes back, giving you less range in the pull)

    no?
     
    Last edited: Oct 13, 2017
  6. jsstevens

    jsstevens Final Approach PoA Supporter

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    I flew most of my PP training in M and N models. The stalls were not hard to get and had a noticeable break. The I flew a C model for quite a few hours and some instrument training. The power off stalls in the C model were very gentle by comparison. I really don't know what the differences were but the C did have a break but it was almost a non-event.
     
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  7. Dan Thomas

    Dan Thomas Final Approach

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    The M models and on have the cuffed wing. It reduces the stall speed a bit and allows a slightly higher stall angle. That can result in a more abrupt stall when it finally lets go. The C model would also have been considerably lighter. And your particular C might have had elevator travel issues, as I noted earlier. A very few degrees less up-travel can make for a slow stall that is more of a sink.