Flap Gap Seal

[GDS]

I'll take one set of your flap gap seals, next time I come to Parker I might have to leave the Hog at home and bring the truck. I also need to smuggle a pint of MEK, we can't get it here anymore... Gil and Ted, come on up to to Big Bear, it's mid eighties and beautiful, 9000' DA

[Trilander Ted]

Gary: Not many hogs in town today, it's 105* and humid (no more "dry" heat),that being said, you can roll them up in a sixteen inch circle. I know you will want to test them out on the way to GIL T's house. Gil & I want to travel to Big Bear in August for the air event, it's comining back in the late afternoon that won't be "cool". You won't need the gap seals until your ready to paint the wings, and don't need much prep except deburr edges, radius corners (3/16 or so), scuff up, and prime. I layed out my rivet pattern ahead of time with a slight stager, then light center punch, and, finish up with Whitney punched holes. Note: I have a Whitney punch, coppied in CHINA, that makes JUNK holes. Fortunitaly, my other toolbox had a genuine Whitney product. I use a #40 drill to make pop rivet holes in the wing, it's a few thousents larger and workes better for me.
I have more .025 sheard 77" long if others if others are interested.
CHEERS Trilander Ted

[Trilander Ted]

Gary: I just realised you are about to become a "smuggler" for LSA folks in California. I don't know how many ounces you half to transport to comit a felony, so I'm thinking there's a beter way. I'm sure there a source for "Medical MEK" in Sourthern California by now. Combine this with the loss of supermarket paper bags, and a big voied appears for those young "HUFFERS" who won't have the means to party properly and therefor advance California's new economey. Maby I should think about airplane gap seals instead of goverment gaps that need sealing. Improved airplane preformance is much easier than improving California's goverment!
CHEERS Trilander Ted

[Johnny C!]

Jonny C! Thanks for your kind word for my WWII primary trainer design wana-A-be tribute colors. I'm an older dude now, and it reminds me of the airplanes I liked as a child.
The engine is the usual 912S with a Kiev three blade prop,(72inch I think). I use the Enigma EFS and a Lorance 2000 and like them well.
I used some heavy black vinyl tape on the flap to stop possible chafe against the gap seal overhang. It's the same type I use to protect leading edges on the horizontal stabilizer, landing gear legs and it works great for gap seals on the elevator/horizontal stabilizer also. (easy trick) By the way, I had to buy a 4 X 8 sheet of .025---6061T6 from Aircraft Spruce as my usual sources didn't stock it. Be sure and use at least 6061 or stiffer. I had eight stirps cut 2 1/2" X 77" and gave four to GIL T. Gil will be back from vacation soon, and wants to install them on 28TU, so we each have an additional set for someone.
It's 117* at my house in Parker, AZ. (5:30PM) so I won't be testing soon!
CHEER'S Trilander Ted

Ted,
Thanks for all the additional info. Good stuff.


My bird was already painted when I learned about
these flap gap seals, so I am going to install each
side in two pieces with the gap at my color change
lines. That will allow me to use a 48" wide sheet of
aluminum. And I don't see any reason why anyone else
couldn't do the same thing to avoid having to buy
the material for full span seals.

Just a thought.

Later!

John

[Dave Krall CFII SEL SES]

It appears there are 2 methods being used: one with a little over 5/8" aft of the trailing edge and one with 1" or more aft of the trailing edge. Almost double the air surface between the two installations.

Any solid evidence consisting of flight data as to which length gives more lift, and in what configurations?

[Dave Krall CFII SEL SES]

It appears there are 2 methods being used: one with a little over 5/8" aft of the trailing edge and one with 1" or more aft of the trailing edge. Almost double the air surface between the two installations.

Any solid evidence consisting of flight data as to which length gives more lift, and in what configurations?

The larger seals that close more of the flap gap will increase air pressure under the wing sooner due to Newton's Law, and at lower airspeeds than the narrower seals, generating lifting pressure and drag under the wing and flap sooner. The narrower seals need more airspeed to start generating lift over the upper side of the flaps, primarily by Bernouli's Principle but, will have less drag.

[KevinC]

Well, whatever law is in effect, I had a chance to try mine for several landings tonight. I REALLY like them! For poor pilots like myself it sure helped to not have nearly as much sink in the flare. It makes me look better...

Levitates off the ground too.

Didn't see any changes in stall or cruise.

k

[Dave Krall CFII SEL SES]

Well, whatever law is in effect, I had a chance to try mine for several landings tonight. I REALLY like them! For poor pilots like myself it sure helped to not have nearly as much sink in the flare. It makes me look better...

Levitates off the ground too.

Didn't see any changes in stall or cruise.

k

One's a Principle, the other's a Law. Great to hear that, which size did you use?

[Gil T]

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Well I guess it was my turn to try to levitate instead of taking off. I went up to Parker and Ted Sutton and I installed the gap seals on 28TU. I did a half dozen take-offs and landings before and after we did the installation to see what the difference was. I think the most noticeable was the nose not pitched up as high on a full flap landing. Another thing was cruising down the Colorado River at half flaps and 50kts and no wallowing around while making s-turns. Seems to be more stable in slow flight. Didn't take time to do any air work since it was 74 at the surface and 93 at 2500 feet at 7:00 AM so I quit early. Take off was consistent at about 150 ft. This was at a density altitude of 2900 ft. Take-off weight was 1050 lbs. I'm not really a fan of full flap take-offs but I was curious. No trouble reaching pattern altitude (800 AGL) 4000 ft down the runway. My gap seals are sticking out 40mm (1.5 in) behind the flap trailing edge. The rivet spacing was 100mm except at the ends. I put silicon sealer under the seals before riveting. This was per Ted Sutton. He didn't want my airplane whistling like a Stuka dive bomber if there was a air gap some place. At this point in time it seems to be and easy and inexpensive mod that can give positive results. I have to withhold total approval until I do some air work with them. I am most interested in how they feel in full flap stalls and cross controlled stalls.

Gil T