Bearhawk STOL mods

[schu]

Bobby, which wingtips are you running? If you aren't using the ones that Battson recommends, might be money ahead to get those going first before you look at bigger tires.

[swpilot3]

For what it's worth, I was stalling clean at 48 KIAS. I put some STOLSPEED vortex generators on my wings and tail. It dropped the clean stall speed to 41KIAS. My full flap stall speed went from 44 to 41 also. I'm certain that my tail is stalling first... I'm sure my forward CG with just me is contributing to this. I'm gonna play with gap seals and ballast for aft CG next.

Another observation is that my current 3-point attitude doesn't allow me to take advantage of the slower speed. I need bigger tires to help take advantage of it.

[schu]

That is a known issue. The cub needs a different tail as well when using keller flaps.

[Mark Goldberg]

I have heard Bob wonder if the tail surfaces have enough control authority for Fowler flaps. Mark

[schu]

I think they must. Once you've done all the engineering and tooling, you've done it all. The only thing remaining is to recoup your investment.
I expect a kit would be over $10,000 plus S&H.

Grrrr, they are so expensive....

[schu]

31" Dessers mounted.

[Battson]

I wonder if airframes will sell a kit to keep the price down a little....

I think they must. Once you've done all the engineering and tooling, you've done it all. The only thing remaining is to recoup your investment.
I expect a kit would be over $10,000 delivered, and it would not be "plug and play". You'll need to modify some of the wing parts.

[schu]

I wonder if airframes will sell a kit to keep the price down a little.... I think this with the other things mentioned would make the bearhawk into a much better bush rig.

[Battson]

For information, I am told the double-slotted Bearhawk flaps are now under production ("Keller Flaps").

For those who are unfamiliar with these flaps, see below for an install on a Maule.

full_flaps.jpg

[Bdflies]

I built a new extended handle, as long as possible without busting my thumb on the cross bar. The 4th notch isn’t easy, but way easier than before.

Bill

[Rollie]

I didn't extend my flap handle. I have been able to get to the fourth notch one handed a couple times by slowing down to below 45 knots. Usually I just use two hands at just over 50 knots. My wife was having trouble getting to the third notch but once she started slowing down an extra 10 kts instead of trying to lower them right at the max speed she has been able to do it. The fun part is learning to pull that hard without pushing on a rudder pedal. I had done it a couple times during my test flying so I expected it when she did it. Not the best time to get way out of trim, especially if you slowed down close to stall to make it easier to lower the flaps.

[Bdflies]

I only use the 4th notch on short final. The 3rd notch is just as you describe. 4th is like air brakes! Great isn't it? I don't pull 4 above 65mph...then it's Game On!
Rollie, did you extend your flap handle? Or can you get the 4th notch with the standard handle?

Bill

[Battson]

Boy, that is interesting.... Sounds like your basic power on stall. Have you continued to the stall to ensure that your AOA is accurate in that situation?

I think Jon is right, makes me think differently about testing fuel flow.

Yes we have stalled it like that, call it "advanced stalls". We can fly around at maximum AoA doing turns up to 30 degrees bank left and right, well out of balance, and it just wont stall. You really need to mistreat it to make it stall.

When you are 50 plus degrees nose up and 30 degrees in a bank, out of balance, and the Bearhawk is holding everything together for you - you develop a deep sense of trust in your aircraft.

Of course all the discussion above is predicated on the plane being at minimum weight. With a load on it's a totally different ball game.

We did some stalls with a new pilot the other day, it was his first flight ever in a plane anything like this - after five minutes of turns we did the stalls, he was easily able to control / recover all but the deepest of wing-drop stalls. He is used to high wing loadings and nasty stall behaviour, so was really impressed. The Bearhawk really is an exceptionally safe plane for pilots.

[schu]

That angle is for Vx, but I can go steeper just for the fun of it. The plane will climb steady state at over 50 degrees to the horizon "hanging on the prop" at about 50 knots. I have seen 55 degrees for short periods. You'd have to see it to believe it. This is practically useless though, just for fun!! Not many planes can do that kind of trick.
I wait for perfect weather to ensure safety, despite a huge margin over the stall showing on the AOA display, call me chicken.

Boy, that is interesting.... Sounds like your basic power on stall. Have you continued to the stall to ensure that your AOA is accurate in that situation?

I think Jon is right, makes me think differently about testing fuel flow.

[Mark Goldberg]

I do not think anybody calls you chicken Jonathan. Much to the contrary. Mark