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Eflite Cherokee

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  • Originally posted by lkruse View Post
    I'm in the process of installing the radio in my PNP Eflite Cherokee. I've not found anything in the manual addressing the elevator off-set for either of the the flap positions. Does anyone who has flown their plane have any advice on the elevator percentages?
    I found no problems with flying the Cherokee with flaps, without any change in the elevator, but due to my own error, I didn't get too many flights out of it before I crashed it. It's still awaiting repair (that's IF it's repairable). IIRC, others have made the same comment concerning flap/elevator balancing.

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    • Originally posted by Hoomi View Post

      I found no problems with flying the Cherokee with flaps, without any change in the elevator, but due to my own error, I didn't get too many flights out of it before I crashed it. It's still awaiting repair (that's IF it's repairable). IIRC, others have made the same comment concerning flap/elevator balancing.
      Thanks for the quick reply. That certainly sounds like a starting point--all except for the crash part!

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      • Originally posted by lkruse View Post

        Thanks for the quick reply. That certainly sounds like a starting point--all except for the crash part!
        As I said, that was my error. I took off, not realizing I was flying at full rates, instead of having my Tx set for low rates with expo, so every tiny movement of the stick resulted in waaaaaaaay too much response from the plane. I had the cameras on the plane, and for a very short time, it looks like I'm having fun with aerobatics. Sadly, though, once I was in that panic-reaction-try-to-recover mode, things just went to hell in a handbasket much too quickly. My Cherokee didn't have the stock gyro stabilization that comes in the RTF or BNF versions, so I didn't have that recovery switch to fall back on.

        Instead, I had the desert to fall back on.

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        • Originally posted by lkruse View Post
          I'm in the process of installing the radio in my PNP Eflite Cherokee. I've not found anything in the manual addressing the elevator off-set for either of the the flap positions. Does anyone who has flown their plane have any advice on the elevator percentages?
          It's not in the manual because it's likely that the manufacturer didn't want it in there. When such information appears in a plane's manual, it is ONLY a suggestion and in many instances, it can be dangerous. Using someone else's numbers is not a reliable or safe way to do this kind of thing (elevator compensation for flaps). It all depends on how you fly and how experienced you are. If you deploy flaps without any delay time and you do it at cruising speed, the plane will very likely "balloon" or in some cases, dive. If done right, flap deployment can easily be manually compensated for and in most cases, elevator compensation isn't even needed. You use flaps (usually 1/2) on take off. The plane is picking up speed and flaps can help with lift at a lower speed. When deploying flaps in preparation for landing, the plane should be powered down so it can slow down in the landing pattern. Real planes don't deploy flaps at cruising speed and they don't slam the flaps down rapidly. They decrease throttle (and airspeed) first and when the speed is adequately reduce, then comes the first stage of flap deployment and this is also done gradually (quite slowly). As the plane slows down even more, then comes full flaps. This should be no different for a model. If done this way, the "ballooning" effect is minimized or non-existent and the need for elevator compensation is negated. Any mild ballooning can easily be manually compensated for because it will be slow and predictable.
          On an unfamiliar model, experiment with flap deployment high up. Make like you're preparing for landing. Slow down a bit before deploying the first stage flaps and see what the plane does. If it balloons, you didn't slow down enough. Then proceed to full flaps after you slow down some more. Understand that flaps will produce lift but it also increases drag and cause the plane to slow down too much and can easily go past its stall speed. Some throttle should be maintained all the way to touchdown. How much of what you need to do and watch out for is a learned thing. Once you get it even close to being right, you'll realize that elevator compensation is unimportant.
          If you really can't get the hang of it, you can always start with something small, like 5% or less for 1/2 flaps, less than double that for full flaps (depending on amount of flap deflection you dial in for each setting). However, you will find that because you need it there, as the plane slows down more, that bit of "down" elevator (to minimize ballooning) is now too much and really shouldn't be there. Now you're using some "UP" elevator to prevent the plane from dropping too much. You've just canceled out the compensation. Maybe it was better to not have it there in the first place. Everyone will be different and whether or not you need it, is also a learned event.

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          • I fly my Cherokees without any elevator to flap mix. I did reduce the flap travel from what the manual suggests. With full landing flaps, the Cherokee is pretty floaty and I end up watching it float by me a few feet off the runway and need to power up and go around. Half flaps is really all it needs, but the plane looks awesome at dusk on final approach with full flaps and lights.

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