We are in the process of sorting out the Sportsman STOL kit parts and pieces. My 182G has flap gap seals already installed. Stene recommends removing them.
Has anybody installed a Sportsman with flap gap seals? Cessna was having a fire sale on rivets when they were doing the trailing edge of the wing and I’m reluctant to drill them all out again and reinstall them.
Any experiences or thoughts?
Thanks.
Chris

25 years ago flap gap seals were the rage. They were installed on my 1956 182 back then. About 7 years ago I put a Sportsman STOL on. I left the flap gap seals on and it works just fine. I am pretty sure that at a 10 degree flap setting the seals block a lot of the air from going over the flaps. At 40 degrees I do not think the seal have any effect. I would just leave them on and fly it a bit. You can always take them off later.

If you’re going to enter a STOL contest or need to shorten your landings for some reason, then yes. If you want to just try it out, then yes. It’s probably going to slow down your top speed a touch, give and take.

I'm still rockin' the gap seals (flap and aileron). No STOL kit.

My 180 came with flap gap seals riveted in place. I added the Sportsman cuff shortly after buying the airplane in 2007. Kept the flap gap seals - well because they are riveted in place. I haven't noticed any issues with the performance. I can land very short - sub 300 feet. I am not sure what the flap gap seals add. Maybe some top end speed and improved climb performance. I am likely to remove them when I paint the airplane next year. The Sportsman made a huge difference in the way the airplane performs.



Josh

Easiest way to remove them, if that what you want, is to scribe a along the trailing edge skin a few times with something sharp then you’ll be able to “break” the gap seal off. No need to drill out and redo the rivets.

Chris, my 53 180 came to me with flap gap seals.
I'd heard that low speed flap performance was better without them,
so I removed them a few years ago.
As usual with my mods, it was not the game changer I hoped for--in fact, I noticed very little difference.
My gap seals were butted against a factory skin edge,
and installed with cherry max rivets.
I drilled them all out (there's a bunch of them!),
and just left the holes as is.



A buddy of mine's 180 has the same row of holes,
so it had had gap seals removed also.
I've heard of some people scoring the gap seals with a razor knife,
and breaking them off--leaving a narrow strip with the row of rivets in place.
Edit: Skinner just posted about this.

Dog is my Copilot wrote:My 180 came with flap gap seals riveted in place. I added the Sportsman cuff shortly after buying the airplane in 2007. Kept the flap gap seals - well because they are riveted in place. I haven't noticed any issues with the performance. I can land very short - sub 300 feet. I am not sure what the flap gap seals add. Maybe some top end speed and improved climb performance. I am likely to remove them when I paint the airplane next year. The Sportsman made a huge difference in the way the airplane performs.

Josh

Yep

Thanks much for the input. I have tossed the scoring and breaking idea out to my supervising A&P. Will see what he says and if he tells me to take up aerial fornication, I think we will just leave them as is.

Since you are going to install the Sportsman cuff, I assume you are interested in improved STOL performance.
To maximize the effect of the Fowler flaps in this area, I would remove the flap gap seals. They impede flow from the lower (high pressure) surface of the wing through the gap and across the flaps. Without them, the flow over the Fowler flaps will separate early (especially at the 30° or 40° position), and the flaps will not contribute much, if any, lift.

To optimize cruise, one would obviously seal all gaps as much as possible, including aileron, elevator and rudder.

In competitive soaring, a lot of effort is spent to do just that by taping off every gap with Mylar tape.

I have flap gap seals and Sportsman on my 185. I tend to get overly focused on stol performance and I was definitely going to take them off. But I ended up just flying a ton with them in the meantime. Once I realized sub 200’ landings in light wind are obtainable with them… what is the point in doing all the work to remove? The plane already performs great. Unless you’re really competing, I just don’t think it is worth it to cut them or drill out all the rivets.