cubdriver2
FRIEND
upstate NY
Looking for thread we had a couple weeks ago on gap seal tape
Glenn
Glenn
Gap seals
- Thread starter cubdriver2
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cubdriver2
FRIEND
upstate NY
skywagon8a
MEMBER
SE Mass MA6
courierguy
MEMBER
Inkom, Idaho
I found some neutral colored foam weather stripping that perfectly seals the gap between my horizontal stab and my elevator on the RANS, and gained 3 MPH top speed and knocked off 2 MPH off the stall! No, not really, but it makes me feel better knowing it's back there and it doesn't add any weight, and I had it leftover from sealing up my doors.
skywagon8a
MEMBER
SE Mass MA6
Was there any speed change? With a fixed stabilizer and a trim tab on the elevator, the two surfaces are not always perfectly aligned. Therefore there could be some tendency for air flow along the hinge line creating a minimal amount of drag. Don't know if it is measurable, particularly on slow airplanes.
courierguy
MEMBER
Inkom, Idaho
My thinking also, it HAS to help. Can't hurt anyway....and other than any "speed increase" (I spend a lot of my time in the 70's, because I like it there) and drag reduction will help climb, range/duration, glide etc. Unless there is a major drawback (like ditching the 29" Airstreaks for 6:00's would be) I'll clean things up when possible.
skywagon8a
MEMBER
SE Mass MA6
Kodiakmack
Registered User
winters in Utah, Summers in Idaho
Any link for a kit for pa-12 with -18 feathers?
Scooter7779h
PATRON
Anchorage, Alaska
I got mine field approved. 11 pieces of paper but walked into FSDO dropped off the application, had a cup of coffee and picked up signed 337. You need to buy the PA-18 STC and have previously approved PA-18 tail feathers to go the way I did.
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cubdriver2
FRIEND
upstate NY
skywagon8a
MEMBER
SE Mass MA6
Just curious, what don't you like about it?
Farmboy
MEMBER
Middlebury, VT
Maule Aircraft does it this way at the factory .
Transmitted from my FlightPhone on fingers… [emoji849]
BC12D-4-85
SPONSOR
Fairbanks, AK.
Not to discourage but tape and fabric can become a trap for snow and ice. Clean it out before flight. Spruce sells a foam seal for Pitts I stuck in my Taylorcraft gaps. Floats in place ok not glued.
Gary
Gary
cubdriver2
FRIEND
upstate NY
skywagon8a
MEMBER
SE Mass MA6
That means it works.
cubdriver2
FRIEND
upstate NY
BC12D-4-85
SPONSOR
Fairbanks, AK.
My goal for the Taylorcraft's seals was to improve elevator trim effectiveness. 1941's had a small elevator tab, later after WWII they enlarged it - like double in length. Now at constant power I can fly via trim full nose up about 5 mph slower - 55 vs 60 IAS. More nose up authority from the seals I guess.
Gary
Gary
What do we know about this stuff?
https://store.cubcrafters.com/Foam-Gap-Seal-Kit-with-STC-for-Top-Cub-and-PA-18_p_1298.html
https://store.cubcrafters.com/Foam-Gap-Seal-Kit-with-STC-for-Top-Cub-and-PA-18_p_1298.html
BC12D-4-85
SPONSOR
Fairbanks, AK.
What's the real question is why the designers of tail surface gaps left them so large? Surely the obvious leakage of air through them didn't escape their observation?
Gary
Gary
skywagon8a
MEMBER
SE Mass MA6
The real answer is Who cares? The airplane has adequate control function in order to pass all the required FAA (or in the case of these planes CAA) tests. The desire to close the gaps is only a personal pilot owner thing. Sure they do something, but they aren't necessary to satisfy the FAA. Perhaps their installation is only to cover up some poor piloting techniques?
frequent_flyer
Registered User
Arizona, USA
It is used on the FX-3 elevator and rudder. I've had mine for about 2 years and about 200 hours of flying. They are easy to fit and remove but they don't fall out. No sign of deterioration in 2 years but the aircraft is hangared. I was concerned that dust and dirt would get trapped in then and abrade the paint but no problem so far.
BC12D-4-85
SPONSOR
Fairbanks, AK.
Bellanca cared enough to close the gaps on their 7GCBC and 8KCAB. Likely others that are promoted for aerobatics but I've not checked. Brisk empennage control authority is desirable by some while exercising proper piloting technique. Then there's the aileron gap seals that promote STOL and roll rate on Cessna's and again Bellancas.
Gary
skywagon8a
MEMBER
SE Mass MA6
This is the question I was answering.
A manufacturer can chose for whatever reason to close or leave open the gaps. The only question they need to answer is "Will it pass the FAA flight tests?" There could be any number of reasons to close or leave open the gaps. Some reasons you may not even think of.
