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

sj

Staff member
Northwest Arkansas
May 3, 2017

Aurora, Oregon - Performance STOL, LLC. is pleased to announce receipt of FAA STC certification of the “Double Slotted” flap system for the PA-18 “Super Cub”. Performance STOL, LLC. is currently working towards FAA Parts Manufacturing Approval (PMA) by the end of July 2017, when certified production will commence.

The Certified Double Slotted Flap System is a bolt-on flap replacement system for the OEM flaps. It also extends the flaps inboard to the fuselage and has the optional provision to shorten the flap handle if desired. It is easy to modify the wing root fairings on aircraft not currently equipped with flaps extended inboard to the fuselage.
FAA approved flight testing has demonstrated a 3 MPH stall speed reduction at a considerable lower angle of attack. The stall speed reduction and reduced stall angle of attack make this modification ideal for “Bush” or off-airport operations and increases the safey margin of the aircraft.

Perfomance STOL, LLC. will accept orders for the STC flap system starting May 6th at 10:00 am. Pacific Time, and will be attending the 2017 Alaskan Airman’s Show and will be accepting orders at the show. Those not attending can refer to www.performancestol.com for ordering instructions. The sales price for the Certified Double Slotted flap system is $8,450.00 plus crating of $150.00. Shipping is F.O.B. Aurora, Oregon. A deposit of $1,000.00 is required to place an order, full payment prior to shipment. Deliveries will be first come first serve, and we will not be able to start until Performance STOL, LLC. receives PMA certification.
 
While I am usually a skeptic, I am surprised that these things only reduce stall by 3 mph. And the big Cessna already has really good slotted flaps.

I am with Mike - way to go! I bet Gary or Steve will be looking at these.
 
While I am usually a skeptic, I am surprised that these things only reduce stall by 3 mph. And the big Cessna already has really good slotted flaps.

I am with Mike - way to go! I bet Gary or Steve will be looking at these.
That's $2816.67 per mph!
 
So basically you are somewhere around $1500 for new stock flaps and another $1000-1500 for cover to paint.
Add $750 maybe to have flaps modded inboard. $3000 (depending) maybe to buy and install new flaps.

Add $1000-1500 to buy and install VGs. Now you are in the 4-5k club.

$8750 for the new flaps boxed and shipped. If you are replacing your flaps maybe this is not so bad. IDK.
 
You might want to go to their website and read about the 'stick shake' and replacing your stabilizer to get rid of it! Also weighs 10lbs more than your stock flaps, if I'm reading that right. That will be about $900.00 per pound (added) after shipping.
 
I was so impressed with the flap that I put them on my experimental Maule a.k.a. Bushwacker. Most things that allow you to fly slower also come with a price i.e. poor visibility over the nose, slower cruise speed. This mod does not have that down side, fly slower and see better over the nose with no cost in cruise speed. Yes they weigh more then a stock flap but the weight penalty is more then made up with in performance gain. I also have a set on my experimental cub, I would never go back to a stock flap again. I built an airplane known as Got Rocks and sold it to an Alaskan before the Keller flap was available. He (Hank) put a set of double slotted flaps on it and when I flew it on the Iditarod one year, I was amazed at the difference it made on that stock wing cub. 3 mph may be all they claim but I think it makes more difference then 3 mph when you look at the sight picture over then nose.

I know for a fact it cost more then 400K to get the STC for the Double Slotted flap. That does not include all the R&D they did to make these flaps a reality. Not many people realize the amount of time and effort a project like this takes including me until I witnessed some of it first hand. His stock cub had strain gages and onboard computers, my guess more then a 100 pounds of gear, it resembled some kind of science project. This is not a simple flap to produce, there are many machined parts along with dies that had to be built for the leading edges in two different profiles, rib dies etc.

Now they have the STC but wait now you have to get your PMA and set your shop up to comply with all that is required to have a conforming part when all is said and done. This is why not much changes in the world of aviation, it is not an easy process!

Good luck to them, I for one am a believer in this flap. I hope they see some upside for all their money and effort!
 
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I have several friends up here running Doug's flaps on experimental cubs, and I think 3mph is a very conservative estimate. And like has been said, there is a dramatic change in angle of attack required to get there. Gives you incredible visibility over the nose. These are definitely going on my cub after the rebuild!
 
Please don't forget us pa-12/14 guys! If ever there was a cub that would benefit from a flatter deck angle approach it's my -14.
 
they do that with a significantly lower AOA. That is the magic of these flaps.

That's $2816.67 per mph!
Eddie, What Dave says is the answer. How many times have you seen videos here of Cubs landing hard on their tail wheel followed by the main gear slamming to the ground when the wing looses lift? Just one of those destructive landings will make these flaps look very inexpensive. Airplanes are not designed to take their primary landing loads in the tail wheel structure.

Did you ever land one of your airliners with the slats retracted? Did you notice how flat the touch down attitude was? These new flaps are the best STOL mod for a Super Cub ever.

Once they get in production for an -18 getting them approved with follow on like airplanes will be a "Relatively" simple process. Congratulations Doug Keller, well done. :up
 
I was so impressed with the flap that I put them on my experimental Maule a.k.a. Bushwacker. Most things that allow you to fly slower also come with a price i.e. poor visibility over the nose, slower cruise speed. This mod does not have that down side, fly slower and see better over the nose with no cost in cruise speed. Yes they weigh more then a stock flap but the weight penalty is more then made up with in performance gain. I also have a set on my experimental cub, I would never go back to a stock flap again. I built an airplane known as Got Rocks and sold it to an Alaskan before the Keller flap was available. He (Hank) put a set of double slotted flaps on it and when I flew it on the Iditarod one year, I was amazed at the difference it made on that stock wing cub. 3 mph may be all they claim but I think it makes more difference then 3 mph when you look at the sight picture over then nose.

I know for a fact it cost more then 400K to get the STC for the Double Slotted flap. That does not include all the R&D they did to make these flaps a reality. Not many people realize the amount of time and effort a project like this takes including me until I witnessed some of it first hand. His stock cub had strain gages and onboard computers, my guess more then a 100 pounds of gear, it resembled some kind of science project. This is not a simple flap to produce, there are many machined parts along with dies that had to be built for the leading edges in two different profiles, rib dies etc.

Now they have the STC but wait now you have to get your PMA and set your shop up to comply with all that is required to have a conforming part when all is said and done. This is why not much changes in the world of aviation, it is not an easy process!

Good luck to them, I for one am a believer in this flap. I hope they see some upside for all their money and effort!

Great user report, thanks.

MTV
 
I got to ride in Doug's Cub for a few hours last week and I'm thoroughly impressed with the flaps.
Getting a fast airplane to go 3 MPH faster is a big deal. Getting a Cub that already lands really slow to land 3 MPH slower and still be able to see where you're landing is huge. It doesn't hurt that the flaps are a work of art.
Good job.
 
There's nothing new about these flaps. They've dominated the EX Cub world for years. The big news is STC approval and that's a big accomplishment. Buy them or don't. The big accomplishment deserves respect and congratulations. Doug has earned both. :up:up
 
This just in: They will be offering an introductory discount of $500 for every set ordered during the Airman’s show. For people not attending the show, they will honor the introductory discount for all orders placed on May 6th and 7th .

sj
 
Just curious, I have a 1954 L21B, as I understand it, the wing has one less rib per side and is a slightly lighter wing. Does the STC cover Pre-1955 wings?
 
Big deal getting the STC approved. Well done. Been thinking about whipping some up for my experimental. I,m thinking foam core composite for the airfoils, alittle aluminum, and some cromoly. Presto! A couple hundred should do it.
 
I was at the Ultima Thule Lodge when Paul Claus flew Doug's first Super Cub with the split flaps. He flew his own airplane first and landed like I had never seen him land before with the tail low, nose high. He then took his GPS and flew Doug's Super Cub. He came in flat and landed. He said he was 3 miles an hour slower in his Cub but did that with the nose up and poor visibility over the nose where he came in flat and could see over the nose with Doug's flaps. I bet if he had more time in Doug's Cub he could have lowered that airspeed. I know if I drag my Super Cub in I can land slower but poor visibility, stresses on the tail in rough terain and less control in gusty conditions prevent me from landing in that configuration much.
 
What about the return spring issue? I've been reading about these flaps requiring a huge spring to hold them up, and resulting in a very stiff flap handle as you get to full deployment.
 
What about the return spring issue? I've been reading about these flaps requiring a huge spring to hold them up, and resulting in a very stiff flap handle as you get to full deployment.

Back Country uses their own hangars and dual bell cranks to hang and deploy 9' plus flaps to 70*. The issue was never with the flaps but with the geometry of the bell cranks. That was not Performance STOL's problem, it was an experimental application problem.
 
Congratulations and what a great step!

anyone going through with an STC deserves support.

I really liked these flaps, and everyone that has flown them and reported has said great things.
 
Only 3 mph??? That's very very conservative.

I have never flown in an aircraft that flies as slow as my BCSC. These flaps are incredible.

These are fully deployed. You can take away maybe 3-5 degrees with blow back and they are still holding strong at around 80 degrees when on short final. There's nothing like them. 20mph touchdowns are real.

Congrats to Doug and all of those that helped with this STC!

AKT

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