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Performance STOL Double Slotted Flap system now STC'd for the PA-18

AKT, Your flaps are double the length of the certified 3 mph ones. I would expect a lot lower speed in your plane.
 
On reading the web site for the flaps, it mentions a stick shake at stall - for those who fly with the experimental variety, it that a noticeable effect? Was it addressed in the STC?
 
Does it slip much differently with the double slotted flaps? Are there still two notches on the flap handle?
 
Airframes Alaska Purchases Performance STOL "Keller" Flaps

FOR IMMEDIATE RELEASE

Airframes Alaska Purchases Performance STOL “Keller” Flaps
August 2, 2017

Chugiak, Alaska - Airframes Alaska is proud to announce the purchase of Performance STOL LLC, designers of the double-slotted “Keller” flap system for certified PA-18s and experimental Cub-type bush planes. Performance STOL flaps lower takeoff and landing speeds by 4 to 5 miles per hour without increasing a plane’s angle of attack in slow flight.

“We’ve watched the development of these flaps for a few years now,” says Heather Montgomery, Airframes Alaska CEO. “The double-slotted flap system is the most effective short takeoff and landing modification for aircraft operating in the backcountry. This makes Performance STOL flaps a perfect fit for what we do at Airframes.”

Doug Keller, a Professional Engineer and ATP-licensed pilot, co-invented Performance STOL flaps with Alec Wild. What began in 2010 as a flap concept for Wild’s Double Ender project gradually transformed into a double-slotted fowler flap design with broader appeal. “The performance was so good that we thought it had market potential for experimental Cubs,” Keller says. “After selling over 100 sets to experimental Cub owners, we started the FAA certification process for the PA-18.” The FAA issued the PA-18 Performance STOL STC in early 2017.

The complete Performance STOL double-slotted flap line now includes:

· STC’d two-hanger flaps for certified PA-18s
· Custom two-, three-, and four-hanger flaps for Backcountry Super Cubs, Javron Cubs, and other experimental Cub-style aircraft

“The FAA has already transferred the STC and added it to our PMA,” Montgomery says. “We’re on track to put Performance STOL flaps into production in late August.” While Airframes Alaska works to fill existing orders, new customers can expect a six-week lead time for experimental flaps and a four-month lead time for certified flaps.


For more information, please call Airframes Alaska at 907-331-4480 or visit www.performancestol.com.


Airframes Alaska LLC is an aviation fabrication and FAA/PMA certified parts manufacturer of tailwheels, landing gear, lift struts, wheels and brakes, PA-18 fuselages, and more essential parts that support bush flying around the world. This purchase is Airframes Alaska’s second acquisition of an Oregon-based aircraft parts business: In 2014 the company bought Alaskan Bushwheels and moved all production back home to Alaska.

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What is the cost? Never mind, I got it off the website.

Are these a two notch flap? Half and Full? How do they perform in the half flap "orbit" mode?
 
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Performance STOL flaps

Thinking of PSTOL flaps on my certified Cub. Now that they have been out there awhile, I am wondering if there have been any service issues. Everybody happy with them?
I understand that most out there are experimental and I have searched the site and read all of the threads. Just wondering if any issues have come up lately.
Tom
 
The owner of the first set in Alaska is thrilled by his flaps and how his cub flies. Great product and great workmanship ��
 
Thanks for the comments. I understand there are very few certified units out there. Thought the experimental guys would chip in. Just wondering if any service issues have shown up. The only weak link I could see are using the original flap hangers. With the doubler, i guess that was addressed. They look very well designed.
Flew the DHC-6 for a number of years. Very impressed by that flap design.
 
Airframes Alaska flaps install

New flaps going on our supercub in Anchorage at Whitewings Aircraft, Lake Hood.
Did the flap brackets in custom red anodizing rather than the stock gold.
Very nice work by Airframes on them, hated to paint them they were so nice bare aluminum.suercub 1.jpegsupercub - Copy.jpegsupercub 2 - Copy.jpeg
 

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There you go Tom, that would be an easy install while you have the wings off!
 
Airframes site claims 3-5mph less takeoff/landing speed. Should work very well on floats as the flaps have lift rather than just drag like stock flaps, so should unweight to get on step far faster in my view.
 
Keller Flaps

Does anyone have experience with the Keller Double Slotted flaps on a seaplane? Do they decrease the takeoff run? How much does it change?
 
Flew the new Airframes Alaska/Keller flaps on my cub this weekend. Very nice performance change. Slower stall speeds, when stalling just tries to hang on without dropping wing, more sink if behind the power curve, stays pretty wings level until forced into full stall. Flatter deck angle for landing. On takeoff, once power applied the tail comes up on its own, no need for any forward stick, just pull back and liftoff. Same with rear passenger aboard, just tail comes up on its own. I have a helicopter airspeed, indicates below 30 mph with some power in slow flight, gps verifies that. Not radical nose high like before. All regimes with flaps very docile. If one is going faster than about 50 mph, each notch of flaps raises nose a bit, does not happen much when adding flaps below 50. Placarded no flaps above 70mph.
All very worth the cost in my view. I like them. See pictures in earlier post.
John
 
Flew the new Airframes Alaska/Keller flaps on my cub this weekend. Very nice performance change. Slower stall speeds, when stalling just tries to hang on without dropping wing, more sink if behind the power curve, stays pretty wings level until forced into full stall. Flatter deck angle for landing. On takeoff, once power applied the tail comes up on its own, no need for any forward stick, just pull back and liftoff. Same with rear passenger aboard, just tail comes up on its own. I have a helicopter airspeed, indicates below 30 mph with some power in slow flight, gps verifies that. Not radical nose high like before. All regimes with flaps very docile. If one is going faster than about 50 mph, each notch of flaps raises nose a bit, does not happen much when adding flaps below 50. Placarded no flaps above 70mph.
All very worth the cost in my view. I like them. See pictures in earlier post.
John

Thanks for the good PIREP John!

Kurt
 
Flew the new Airframes Alaska/Keller flaps on my cub this weekend. Very nice performance change. Slower stall speeds, when stalling just tries to hang on without dropping wing, more sink if behind the power curve, stays pretty wings level until forced into full stall. Flatter deck angle for landing. On takeoff, once power applied the tail comes up on its own, no need for any forward stick, just pull back and liftoff. Same with rear passenger aboard, just tail comes up on its own. I have a helicopter airspeed, indicates below 30 mph with some power in slow flight, gps verifies that. Not radical nose high like before. All regimes with flaps very docile. If one is going faster than about 50 mph, each notch of flaps raises nose a bit, does not happen much when adding flaps below 50. Placarded no flaps above 70mph.
All very worth the cost in my view. I like them. See pictures in earlier post.
John
Thanks for the report! Couple questions.....Are the forces on the flap handle any greater to deploy the Keller flaps? Do they droop at all when retracted? I’ve read about that problem on the larger, multi hanger exp. versions. Do you have more than two notches and where are you leaving them for takeoff or are you popping them? After painting, how much weight did you gain? Sorry for all the questions and if you answered some of them earlier I apologize!
 
About 10 lbs added weight. Installed the heavier flap springs, but I cannot tell much difference in pull at all. No droop in them with heavier springs.
I have not popped them, prefer to use the added lift from the fowler type flaps, like a Husky flap, they now provide some lift with the double slots, not just drag. Not enough time to know shortest, but sure raises tail almost instantly by itself now, then just lift off.
Best shortfield on Husky is full flap, back pressure and levitate, no tail raise as it flies off three point shortest, this seems to be similar. If you pick tail up on Husky you went to far, no need to tail raise. These new flaps seem to do the same, just back pressure after tail is automatically up and back pressure and you are flying. Popping might be shorter, but have not tried it, to me one more thing to take your eye off liftoff, and these flaps have some lift now. Two notches may be better than three for takeoff, not sure yet. Three for landing shortest.
John
 
If money was no object, with a exp cub, would you go 2, 3, or 4 hanger flaps like the glacier cub. is there sortve a guideline??
 
My flaps are 110" long with four hinges and two push rods. If I were to install these flaps they would be the same length. If I found that the maximum deflection angle was too much, I would reduce it a few degrees. I believe in long high aspect ratio flaps for low speed performance. The extra slot helps bend the airflow forcing the flap to operate efficiently at large deflection angles.
 
I don't know the Glacier Cub specs (what ever happened to that plane???) but the Mackey SQ-12 uses 12' of split flap on each wing. It seems to work pretty well. The new Backcountry Rev 3 wing uses a new design split flap, I believe it's also 12', and it only deflects 30* but uses deeper chord. I suspect the mechanical pressures on these long flaps with 70* droop are exceeding the control capacity? Can't say for sure.

https://www.youtube.com/watch?v=QFllgHbjnlU
 
I am fairly use to flying airplanes with big flaps and small ailerons. Bushwacker was 126" of flap and 54" of aileron before I changed it to 120" of flap and 60" of aileron. It still was not enough to arrest a severe roll induced by a nasty gust which ultimately caused the aircraft to impact mother earth.

I built my Super Cub with 110" of flap and 90" of aileron thinking this would be more then enough to make the airplane easy to handle in gusty conditions. The airplane has not let me down yet but there are times when I am full aileron and full rudder waiting for the airplane to realize the input in nasty conditions. When I build my next Super Cub it will be just the opposite if I build another long wing cub. 110" of aileron and 90" flap.

I think unless you are going to have some kind of spoilers helping out with roll it is best to stay with at most a 50/50 ratio.

Both Bushwacker and my Super Cub have Keller double slotted flaps.

Just my .02
 
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