Drooped ailerons
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Cubus Maximus
Registered User
When the camera shows this L-21 from directly above you can see the aileron droop system pulleys:
http://www.alaskaaerials.com/video/super-cub-anwr/
Steve Pierce
BENEFACTOR
Graham, TX
Dennis you need to pay Jerry Burr a visit.
D&E has a drawing of a droop system using the pacer style set up. From what i remember it is a whole lot simpler than the cub style. If i were doing a droop system on a cub i would use the 12 style controls and reroute cables, you could build your own bell cranks and add a additional arm on them to operate spoilers for positive control at low speeds something that is missed on all cub modified systems i have seen so far except for the highly modified 12 that calkins and erikson did. It all sounds heavy to me.
bob turner
Registered User
How is the low speed roll control on this bird?
Robertson had to reduce the droop for roll control. At full droop, low speed control was barely adequate on the 180/185.
Robertson had to reduce the droop for roll control. At full droop, low speed control was barely adequate on the 180/185.
Dave Calkins
Registered User
Anchorage, Alaska
bob turner said:
Bob, if you are asking about what Gander called "...highly modified 12 that calkins and erikson did..." , the roll authority with the coupled roll spoilers is excellent. The roll spoilers will become a standard on a good-flying drooped Cub, in my opinion. Others without roll-spoiler have scared a few pilots, as they need a full boot of rudder when down and dirty to affect a course change...so I am told.
Gander mentions "...it all sounds heavy...". An aileron droop system is not heavy. A roll-spoiler system is not heavy.
Dave Calkins
Registered User
Anchorage, Alaska
Dennis and Cubflier, Hello.
Yes, I can tell you what it is, and yes, I have a picture of one.
The "Custom Cruiser" is heavy. It is a Smith PA-12 replica with 5, count 'em, 5 doors, aux tanks, full metal headliner and interior, 4-Atlee long steps, etc....................................................................................................etc....................................................................................................etc..................... performance-wise, you would be blown away that a heavy "Cub" would fly like this. It proves that the aerodynamic mods on it are working. This aircraft will turn around on its wingtip when slowed-up.
First, the picture, showing an inboard and an outboard spoiler. The outboard spoiler is coupled proportionally to the ailerons only when the aileron-droop has been selected. Also, the inboard and outboard spoilers are both deployed simultaneously and symmetrically on both wings as a descent spoiler system, which is aLOT of fun.:
This roll spoiler system mimics the Helio Courier "lift interrupter" system in shape of the blade. The blade is about 29 inches in span and deploys about 3 inches above the wing upper surface.
It is molded carbon fiber to save substantial weight over the aluminum/steel Helio-style blade-assembly. It deploys through a slot in the upper wing surface about 6 inches aft of the front spar and is situated to take advantage of "spoiling" a portion of the high-speed air coming through the Wayne Mackey slats.
The spoiler both creates drag and interrupts lift on that portion of the wing, assisting in bank and controlling adverse yaw (adverse yaw is why we have rudders, to help keep a turn coordinated).
The roll spoiler provides very good roll authority with an aileron droop system and a Wayne Mackey slat system, with everything hanging out and the a/c at minimum controllable airspeed.
Another factor on this modified Smith PA-12 replica is that the PA-12 aileron belcrank geometry was significantly changed to provide greater differential ('up' aileron goes up more than the 'down' aileron goes down) in order that with full aileron droop selected, and the control stick racked all the way over, the 'down' aileron doesn't go any further down, but the 'up' aileron actually does go up.
This differs from some recent iterations of the droop aileron system.
Yes, I can tell you what it is, and yes, I have a picture of one.
The "Custom Cruiser" is heavy. It is a Smith PA-12 replica with 5, count 'em, 5 doors, aux tanks, full metal headliner and interior, 4-Atlee long steps, etc....................................................................................................etc....................................................................................................etc..................... performance-wise, you would be blown away that a heavy "Cub" would fly like this. It proves that the aerodynamic mods on it are working. This aircraft will turn around on its wingtip when slowed-up.
First, the picture, showing an inboard and an outboard spoiler. The outboard spoiler is coupled proportionally to the ailerons only when the aileron-droop has been selected. Also, the inboard and outboard spoilers are both deployed simultaneously and symmetrically on both wings as a descent spoiler system, which is aLOT of fun.:
This roll spoiler system mimics the Helio Courier "lift interrupter" system in shape of the blade. The blade is about 29 inches in span and deploys about 3 inches above the wing upper surface.
It is molded carbon fiber to save substantial weight over the aluminum/steel Helio-style blade-assembly. It deploys through a slot in the upper wing surface about 6 inches aft of the front spar and is situated to take advantage of "spoiling" a portion of the high-speed air coming through the Wayne Mackey slats.
The spoiler both creates drag and interrupts lift on that portion of the wing, assisting in bank and controlling adverse yaw (adverse yaw is why we have rudders, to help keep a turn coordinated).
The roll spoiler provides very good roll authority with an aileron droop system and a Wayne Mackey slat system, with everything hanging out and the a/c at minimum controllable airspeed.
Another factor on this modified Smith PA-12 replica is that the PA-12 aileron belcrank geometry was significantly changed to provide greater differential ('up' aileron goes up more than the 'down' aileron goes down) in order that with full aileron droop selected, and the control stick racked all the way over, the 'down' aileron doesn't go any further down, but the 'up' aileron actually does go up.
This differs from some recent iterations of the droop aileron system.
behindpropellers
Registered User
NE Ohio
mvivion said:
Tim Allen's 2+2 has spoilers. I think it was built 20 years ago.
perhaps a more efficient approach may be larger flaps like 12 plus feet and shorter ailerons but use spoilers maybe even deeper frise style ailerons like on a helio, they would require counter balancing. It would be easier to build vs the drooping ailerons plus spoilers and results would probably be the same. I still think the more you put on the heavier it gets and is the pay back in performance worth it????? But it sure is cooool.
cubdriver2
FRIEND
upstate NY
Taylorcraft L2 also 60 + years ago
Glenn
Glenn
cubflier
MEMBER
Palmer, AK
The ideal droop system for me would be on that has an on/off capability and is light. I don't think I would need a ton of droop either. Maybe a couple of inches or so max.
Has anyone ever weighed a specific droop system? Not much sounds great but I'm just wondering what they really add.
Jerry
Has anyone ever weighed a specific droop system? Not much sounds great but I'm just wondering what they really add.
Jerry
skywagon8a
MEMBER
SE Mass MA6
What ever drooping system that you use, you should not have it mechanically tied to the flaps. It becomes a problem in a crosswind when you need all of the up aileron that you can get. The spoilers as seen above, or something like them, should solve this problem. The flap/aileron link is the problem with the Robertson.
bob turner
Registered User
So the answer is that, without spoilers, drooped ailerons are not a good idea. That is what I was thinking.
I love the idea of spoilers and Fowler flaps, and Mackey leading edges. That sounds like a winner!
I fly an L2 Taylorcraft with spoilers, and they convert it to a moderately fast Piper Cub - when you get established in the flare, you pull the spoilers and land. Not legal, but sure beats sailing down the runway in full flare mode. They are truly neat!
I love the idea of spoilers and Fowler flaps, and Mackey leading edges. That sounds like a winner!
I fly an L2 Taylorcraft with spoilers, and they convert it to a moderately fast Piper Cub - when you get established in the flare, you pull the spoilers and land. Not legal, but sure beats sailing down the runway in full flare mode. They are truly neat!
skywagon8a
MEMBER
SE Mass MA6
bob turner said:
This is not an accurate answer. I have had drooped ailerons on my 185 for many years and would not want to be without them. I just don't use them in strong crosswinds or when landing. Without them, I would not be able to get out of the water, on amphibs, while indicating only 37 knots. They need to be able to be operated independently of the flaps.
I have drooped ailerons on my SC and I have made them to droop 1/2 of the flaps just like the German Storch. I can select flaps only with out the droop also.
With ailerons drooped 1/2 of flaps still allows me to weave around the trees on short finale.
You have to learn to fly the aircraft with the droopys. If you don't have an aileron disconnect you approach with a little flap and as you get closer you apply more and on very very short finale you pull all of it.
You have to be ready to use rudder on the flare to control roll.
Also if you fly the airplane on short finale and cut the power to glide in like most pilots do, the droopys don't control roll very good.
If you make your approach by hanging it on the prop, the droopys work a lot better for roll control.-----Take care
With ailerons drooped 1/2 of flaps still allows me to weave around the trees on short finale.
You have to learn to fly the aircraft with the droopys. If you don't have an aileron disconnect you approach with a little flap and as you get closer you apply more and on very very short finale you pull all of it.
You have to be ready to use rudder on the flare to control roll.
Also if you fly the airplane on short finale and cut the power to glide in like most pilots do, the droopys don't control roll very good.
If you make your approach by hanging it on the prop, the droopys work a lot better for roll control.-----Take care
Dave Calkins
Registered User
Anchorage, Alaska
gander said:
Long flaps/no droop..............Perhaps. I believe we will have an answer this spring. (Wayne Mackey never sleeps).
I believe you are "...leaving some performance on the table..." when you don't camber the entire wing trailing edge (TE). We have discovered that roll spoilers allow us to have authority and also camber the whole TE.
Long flaps/no droops easier to build? maybe.
More you put on.................adds weight, no argument! Some things are worth it, some aren't. I don't see a need for 5 cabin doors and a baggage compartment you can drive a jeep on.......................BUT my Cub will have slats and selectable droops (though I never turn off the droops since the roll spoilers work so well on the Custom Cruiser).....after my C180 flies and my Bartender floats.
One beauty of the droops is the deck angle with them is 5 to 10 degrees less.....in other words.....Fly along with the flaps out and slowed waaaayyyy down, then droop the ailerons, and the nose will come down, yet the a/c doesn't gain speed..it only gains over the nose visibility..........................worth pure gold!
I believe Tim's 2+2 is set up with descent spoilers.
Dave Calkins
Registered User
Anchorage, Alaska
cubflier said:
I no longer turn the droops off................up to a gusty 18MPH 45degree crosswind. I have not tested it beyond that with a crosswind landing or takeoff.
D
Dave Calkins
Registered User
Anchorage, Alaska
Re: droopy ailerons
Wayne Mackey has been recommending VG's one inch behind the slat. Probably a lot more -18 based aircraft than stuff like Ron Kakeldy's Custom Cruiser ehich utilizes the slat/vg/droop configuration.
PS The wing incidence on the custom cruiser has been increased. It is NOT a PA-12, nor an -18 either.
RMEAV8R said:
Wayne Mackey has been recommending VG's one inch behind the slat. Probably a lot more -18 based aircraft than stuff like Ron Kakeldy's Custom Cruiser ehich utilizes the slat/vg/droop configuration.
PS The wing incidence on the custom cruiser has been increased. It is NOT a PA-12, nor an -18 either.
Dave, i still believe just having large flaps with short ailerons with the spoilers inter-tied to then is probably the way to go. When you start putting handles in the cockpit all over to control ailerons and another for spoilers it gets more complex and heavy and there is not that much room in a standard 18 style fuselage. This is coming from a everyday flyer, hunting, spotting alaska usable working plane approach. The less gadgets to deal with the better.
