Steve Pierce
BENEFACTOR
Graham, TX
Come on Kase, what a ya think?
Performance STOL Double Slotted Flap system now STC'd for the PA-18
- Thread starter sj
- Start date
Come on Kase, what a ya think?
kase
SPONSOR
Billings MT
Not my cub so take my pirep for what its worth. Owner is out of town for the month and gave me the keys and said try it out. At 4200 density altitude with no wind touch down was 34-35 mph on the gps carrying power. Touch down is in 3 pt attitude not the tail wheel being 2 ft lower than the mains. Wheel landings worked good at 42 mph using the gps for ground speed. Does fly slower with out as much AOA as it did before.
Installed cost around 10k. Cost you about 2k for every 1 mph slower your going. Cub is stock except for vgs, gear and fwf. Only has 1 becker com. No thrustline, ext baggage, map pockets X bar etc. 1040 lbs empty weight on paper.
Installed cost around 10k. Cost you about 2k for every 1 mph slower your going. Cub is stock except for vgs, gear and fwf. Only has 1 becker com. No thrustline, ext baggage, map pockets X bar etc. 1040 lbs empty weight on paper.
BC12D-4-85
SPONSOR
Fairbanks, AK.
A Pacer could use them.
Gary
Gary
mvivion
SPONSOR
Bozeman,MT
That sounds like a really sweet cub.MTV
john schwamm
SPONSOR
Anchorage, Alaska Carefree, AZ
If tested near sea level the performance is much better. Great mod in my view. I like them, and my cub weighs in 1250 lb range.
John
SchulerJL
BENEFACTOR
Peoria, Illinois
I found that with the shortened flap handle that last notch can be very difficult to pull above 50 -55 mph. I had a flap assist handle fabricated that greatly improves activation. I can even get them on in the 60 -62 mph range. My flaps are standard length flaps on a 1954 PA18 L21B
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mike mcs repair
Registered User
chugiak AK
if it takes more than 2 fingers under the flap handle to pull them on, you are going to fast to need to deploy them for how you are loaded, for that next notch.... is what i was taught
alaskadrifter
Registered User
Alaska
Agreed! Also, has anyone used them on floats?
SchulerJL
BENEFACTOR
Peoria, Illinois
I agree, the shortened flap handle however makes that very difficult. Essentially by adding the sleeve, you are keeping the flap handle the original length and yet keeping it out of the way of your leg giving you full aileron deflection to left during a left crosswind landing.
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john schwamm
SPONSOR
Anchorage, Alaska Carefree, AZ
Mine was on floats this summer for a bit, the flaps are also great improvement on floats.
John
John
skywagon8a
MEMBER
SE Mass MA6
I must be missing something. I can not visualize how the L on the flap handle replaces the original length. Perhaps a better grip but not more length which will improve the mechanical advantage.
SchulerJL
BENEFACTOR
Peoria, Illinois
Having taken Physics over 30 years ago, and being a medical professional not an engineer, there seems to me to be a mechanical advantage to it. The grip is definitely improved as your had runs into the seat as you pull back and loose grip without it. You push the flap button in with the thumb part of the palm of your hand not your thumb. Nothing worse than thinking you have that last notch in and then they slam shut to the first notch on short final at 40mph at 30 feet above the ground. Any engineers out there who can explain it to me if there is or is not a mechanical advantage to it?
Gordon Misch
MEMBER
Toledo, Wa (KTDO)
I'm usually a sucker for that, so I'll try. Mechanical advantage is simply the amount of motion for an input force divided by the amount of motion for the output force. And the forces are related reciprocally to their respective distances. In this case we're caring about the force a hand/arm assembly has to apply to the flap lever to get a desired output. If the hand arm assembly has to travel farther, the required force will be less, hence greater mechanical advantage for the flap lever. BUT, it's also necessary to consider the levers and force-producers in the hand/arm assembly. The biomechanics. That's for you medical guys!! Biomechanical effort seems to not always correlate closely to what "seems" obvious for a mechanical system. So I'd say, if it feels easier, it is - notwithstanding the specifics of the mechanical system.
I got interested in this idea by watching the paths cattle and dogs and horses take to move through terrain. It usually isn't the shortest path, or even the least energy path (you engineers out there will recall the "least work" principle as it relates to mode of deformation). I decided that a "least effort" principle applies. Though I've been unable to define "effort" well, I think it has to do with minimizing abruptness. I've used the principle to lay out walkways by walking paths with my eyes closed. The "least effort" path is never a simple geometric - it's always a smooth curve though. Of course this is only remotely related to the flap handle question, but it suggests that the best configuration might vary from what seems obvious.
I got interested in this idea by watching the paths cattle and dogs and horses take to move through terrain. It usually isn't the shortest path, or even the least energy path (you engineers out there will recall the "least work" principle as it relates to mode of deformation). I decided that a "least effort" principle applies. Though I've been unable to define "effort" well, I think it has to do with minimizing abruptness. I've used the principle to lay out walkways by walking paths with my eyes closed. The "least effort" path is never a simple geometric - it's always a smooth curve though. Of course this is only remotely related to the flap handle question, but it suggests that the best configuration might vary from what seems obvious.
I think I can explain what is going on but it well past one glass of whine so I will give it a shot. From a medical standpoint the little finger has a lot to do with grasp strength. If the seat is pushing it off the handle, that will be a issue (Orthopedic thing). You have also added a mechanical advantage by putting your wrist over the top of the handle. If the seat is pushing your hand off the flap handle then the short handle is the problem!!! BUT!!! Why do you have a short handle??? Oh ya, you want to use full stick to the left! Might want to just push with the left foot a bit more. So, if it works for you I would stick with it. For the rest, bend the flap handle as needed, or for the short handle people look at Mia Hamm in the morning(3 points for knowing what the Mia reference means).
DENNY
DENNY
skywagon8a
MEMBER
SE Mass MA6
I think that I get it now. You physically can not move your arm back far enough to engage the last notch of flaps due to the tight space between your body and the side panel. So the L extension is really just pushing the lever further aft The force required isn't any less, you just don't have to put your arm behind your back. I assume that you push the release button with the heel of your hand rather than your thumb.
BC12D-4-85
SPONSOR
Fairbanks, AK.
I wonder if the flap handle could be curved forward or just bent some? it would be closer to the floor at the release button. That might make it easier to pull full flaps (less body twist required) and maybe less leg contact.
Gary
Gary
john schwamm
SPONSOR
Anchorage, Alaska Carefree, AZ
If backyard design/built then not certified, only good for experimental if homebuilt.
These are like jewelry, took many years to get them approved too. Try making something like these on your own and see how they might work.
These really work and are an excellent addition to certified cub.
John
These are like jewelry, took many years to get them approved too. Try making something like these on your own and see how they might work.
These really work and are an excellent addition to certified cub.
John
SchulerJL
BENEFACTOR
Peoria, Illinois
I'm going to agree with this. I don't think it changes the force in retrospect. I asked Airframes if they could make a new handle with a bend - no can do - has to be same on certified plane. Since this is just a grip that slides on it was the best solution I could find and it really helps.
Mauleguy
MEMBER
You have obviously not looked at the amount of sheet metal and machine work that went into making these flaps. There are complex bends in the sheet metal in the first and second segments that have to be made to have all the contours correct so they nest nicely plus the leading edge bends. Then there is the geometry of the vane hangers/extenders/linkage that makes these things work properly. It's not that you could not do it but if you value your time I don't think the price is out of line.
mike mcs repair
Registered User
chugiak AK
we used to heat and bend every flap handle more to the side when we shortened them 3".....
SchulerJL
BENEFACTOR
Peoria, Illinois
That would have definitely helped. The STC for the flaps also includes the option for the shortened flap handle. It would have been great if that was included in the STC.
Olibuilt
MEMBER
Montreal, Canada
Would like to have a closer look, but non of these around here.
I don't doubt the technology and quality involved in those flaps...
But Bushwheels are way harder to fabricate, for me anyway. I would not even try...
If money was not a factor, I would have bought a set a while ago.
I will continue to explore a way to fabricate myself something similar for way less money, but much more time, like I always did. That is the fun part I think.
Look at the Rev 3 flaps. Simpler and lighter. Performance reports are good. A guy could fab those easier than split flaps. Big chord, big span, and ducted leading edges. I'm looking forward to seeing more of them flying.
Or, here's a novel idea. Create something better!
Or, here's a novel idea. Create something better!
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john schwamm
SPONSOR
Anchorage, Alaska Carefree, AZ
Will be hard to make flaps with dual slots and all lift from them, vs drag on stock flaps any better than the Keller flaps in my view. Doug worked to perfect these for years.
They are jewelry and work perfectly and also look very cool. Doubt anyone doing a one time one off set will come up with the details and function of Doug's creations. Much less be certified.
If experimental cub, then go for it, but the lift from these, like a Husky flap is what gives the performance improvements. Slower controlled flight, slower stall, nose down attitude, etc. They do it all.
Doug seemed to make it all work. And they are perfect fit on a stock cub. Plus certified.
Just my view. Like experimental stuff too, but these are hard to beat for standard cub. Costly, but best bang for the $$.
John
They are jewelry and work perfectly and also look very cool. Doubt anyone doing a one time one off set will come up with the details and function of Doug's creations. Much less be certified.
If experimental cub, then go for it, but the lift from these, like a Husky flap is what gives the performance improvements. Slower controlled flight, slower stall, nose down attitude, etc. They do it all.
Doug seemed to make it all work. And they are perfect fit on a stock cub. Plus certified.
Just my view. Like experimental stuff too, but these are hard to beat for standard cub. Costly, but best bang for the $$.
John
bob turner
Registered User
I think these flaps are probably worth every penny. Do I have this right - the kit only costs $8400 US?
However, if they are no better than the Husky flaps, I would pass, unless Husky made some major improvements beyond the B model.
However, if they are no better than the Husky flaps, I would pass, unless Husky made some major improvements beyond the B model.
skywagon8a
MEMBER
SE Mass MA6
bob, Husky flaps are at least twice the length of Cub flaps so that is comparing apples and oranges. The comparison needs to be made on flaps of the same length.
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