I have a question regarding the Keller Flaps. How do the Keller slotted flaps work in conjunction with leading edge slats? I have read that slats need to have an increased angle of attack to be effective while the Keller flaps give you a flatter approach. So how would a Cub/Pacer fly with them both installed? Are slats even required if you have the Keller flaps? Also I have an off topic question. Is there anyone who sells SC horizontal stabilizers with a symmetrical airfoil? Thanks!
Keller (Perfromance) Flap question. Needing more tension some how??
- Thread starter Aktahoe
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Albertasq2
Registered User
My cub a backcountry SQ2 has both. It's amazing! We mounted the slats at the new location as per Backcountry's spec. Only downfall is the slats are now on in cruise. Which causes you to lose a bit of speed. The advantage is the slats are always doing their job now. No high angle of attack needed. Plus we made manual locks on the slats if we want the few mph back for a long ferry. We tried flying it without slats. Without slats you'll get a very quick wing drop without any shudder on the SQ2 wing. Not what you want when you're trying to land as slow as possible in the bush.
With slats on and full flaps it's almost unstallable. It won't ever drop a wing. The whole airplane will slowly descend like a piece of paper falling flat. With full flaps and slats I can come in on final with the ASI reading zero and it's completely ok. I believe it stops registering at about 18ish mph indicated.
Now with the Keller flaps and slats I can come in on final with amazing viz and not have to have the nose high to work the slats.
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How many mph is a bit in your case?
Albertasq2
Registered User
Hey Jim
I don't have any vids at the moment, but once it warms up here I could probably find some one to video. Kevin Quinn also has a cub with both and he videos all the time. You can search him on FB or I believe he's on this site as well. I'll see if I can find his user name.
Thanks
Dustin
Albertasq2
Registered User
AKtahoe is kevin he posted above in this post.
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Albertasq2
Registered User
Believe we gained 13mph when we took the slats right off and gained about 5ish with them on and locked closed. So not really a big deal on an airplane designed for going low and slow anyways.
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Albertasq2
Registered User
I had an oops on a bad crosswind landing and we had to install new wings on the bird. Not a good day. Anyways, we brought it back to the factory to get the repairs done. When it was time to install the brackets for the slats they just told us a measurement where to mark the bracket holes. The brackets are the exact same as before. Just different spot. Bruce didn't tell us yet this was different from the original slat location. Then on the ferry home we noticed the slats were on all the time. Then he explained. Best would be to call Backcountry for the measurement as my memory is foggy on whether its higher up or lower on the leading edge. It was some SQ guys in Alaska I believe that were first playing around with mounting locations. That's where backcountry got the measurement from.
Since it's a slow airplane anyways, and most install 35's the added drag is minor. Sorry I should have wrote down what the difference in mounting location was.
Thanks
Dustin
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Jonnyo
Registered User
Fairbanks, Ak
Quote: One of the videos showed a hand pushing one flap up. Unless an equal force was applied to the other flap at the same time, this would not be a valid demonstration of blow back due to the "Y" arrangement of the cable in the fuselage. In flight the air loads on the flaps will balance each other. Quote:
Thank you for pointing this out.
Thank you for pointing this out.
mike mcs repair
Registered User
chugiak AK
actually the cable system on a rev 2 is not like the Y in an -18, it's the Y system like in a -12 or -14, which is not as susceptible to one side off setting the other because of where the 2 cables splice together and just go strait up door post on opposite sides of pulley on ONE bolt, not opposite sides of FUSELAGE like an -18...
if a rev 2 is who they talk about (AKtahoe's video....)
