AIRFOIL TAILFEATHERS
- Thread starter S2D
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cubdrvr
SPONSOR
YKN(mother city of the dakotas)
I think that is pretty typical for a cub under those conditions. I don't notice it so much at cruise (2450 with a big prop) but at a lower power setting as when you're checkin' out that big buck or takin' pictures I always run with 1 notch of flaps when heavy.
murph
Registered User
Rotan, TX.
The early Thrushes have the Cub-type tail surfaces and the later models have the flying tail. I have 3 older ones and one newer model. To tell you the truth, I can't tell much difference in the way they fly, loaded or empty. But with 1000 hp, you can overcome most drag issues.
murph
murph
Gary Reeves
SPONSOR
Lake Clark National Park, Alaska
Correct me if I'm wrong - I imagine some will correct me even if I'm right-, but upward lift from a tail would present some interesting stability problems.
I was under the impression that a well trimmed tail flys upside down - ie the lift is down - not up. The up side is the pressure surface and down is suction. worry about frost and ice on the underside of the tail and put your micro VGs there too- not on the top.
Gary
I was under the impression that a well trimmed tail flys upside down - ie the lift is down - not up. The up side is the pressure surface and down is suction. worry about frost and ice on the underside of the tail and put your micro VGs there too- not on the top.
Gary
Gary, you're right. They fly with a tail download to offset the nosedown pitching moment of the wing, enhancing stability. As an aside, I do research on the flapping and soaring kinematics, unsteady flight mechanics, and biomechanics of a couple of late-Cretaceous azhdarchid pterodactyls that do fly with a tail upload (usually), and it makes for some really interesting stability issues.
All the best for the holiday season,
JimC
All the best for the holiday season,
JimC
Gary Reeves
SPONSOR
Lake Clark National Park, Alaska
Yes, and if you stall the tail (loosing Flow) the tail goes up and the nose goes down. Not an unstable situation . Perhaps not fun, but stable.
Gary
Gary
PA12driver
Registered User
Battle Ground, WA
That's why the VG's are on the bottom, now I am getting it!
You engineer types amaze me! Sure glad you were in class when I was out hunting!
Tim
You engineer types amaze me! Sure glad you were in class when I was out hunting!
Tim
Jerry Burr
MEMBER
Sedro Woolley, Washington.
Tail Stall.
Hey Tim. I couldn't make your Fly-In. Had the flu. Next time. I'm glad you figgured out how the tail works. There is a quite simple rule. If your freight weighs more than your propeller, then the tail stalls down instead of up and you had better have a real good back up plan.
Take Care. Jerry.
Hey Tim. I couldn't make your Fly-In. Had the flu. Next time. I'm glad you figgured out how the tail works. There is a quite simple rule. If your freight weighs more than your propeller, then the tail stalls down instead of up and you had better have a real good back up plan.
Take Care. Jerry.
Dave Calkins
Registered User
Anchorage, Alaska
Tim, you shoulda been playing with rubber-band powered model airplanes some of that time 'nstead of hunting.
I'm surprised at the number of "real" pilots that didn't have the flying bug enough as kids to spend most of their play time messing with model airplanes, and learning at a young age the way this stuff works.
No offense, Tim. I'm just surprised.
Dave Calkins.
I'm surprised at the number of "real" pilots that didn't have the flying bug enough as kids to spend most of their play time messing with model airplanes, and learning at a young age the way this stuff works.
No offense, Tim. I'm just surprised.
Dave Calkins.
Little_Cub
MEMBER
Palmer, Alaska
Flying Tail
Life to an ol' thread - Has anyone worked with a flying tail? We have some tail turbulence when >30 degrees flap.. also the tail wants to stall a bit early when slow. Will simply squaring and enlarging the elevator be enough?
thoughts?
Thanks in advance
frank
Hey Tim. I couldn't make your Fly-In. Had the flu. Next time. I'm glad you figured out how the tail works. There is a quite simple rule. If your freight weighs more than your propeller, then the tail stalls down instead of up and you had better have a real good back up plan.
Life to an ol' thread - Has anyone worked with a flying tail? We have some tail turbulence when >30 degrees flap.. also the tail wants to stall a bit early when slow. Will simply squaring and enlarging the elevator be enough?
thoughts?
Thanks in advance
frank
KenyaCub
Registered User
Kenya, Africa
The airfoil horizontal stabilizer that Doug makes will sort out your issues. Initially he made the airfoil only on the bottom, which has the most effectivness, but on one cub we tried it on we ran out of forward trim. We recently tested a symmetrical airfoil and that solved the trim issue on that particular cub. So several options are possible.
There is almost no added weight. They are a big improvement over stock. Talk to Doug.
I've been testing several other designs but those were meant for the DoubleEnder and would be difficult to adapt to a cub unless at rebuild. They are also overkill for a cub.
There is almost no added weight. They are a big improvement over stock. Talk to Doug.
I've been testing several other designs but those were meant for the DoubleEnder and would be difficult to adapt to a cub unless at rebuild. They are also overkill for a cub.
