Installing Gap Seals. Pro/Cons

Woodsum · Post by **Woodsum** » Fri Oct 17, 2003 1:33 am

I've enjoyed the comments on the various subjects since I aquired my 55 "B" model in April. I've since installed a windshield, headliner, "push tube", brake disks, avionics, and new paint, with lots of help from reading these subjects on the Forum. You guys are doing a great job. I haven't seen much regarding installing Gap Seals on the flaps and/or ailerons. I've installed them on a previously owned Skylane, and would appreciate comments relative to installation on the 170.

N170BP · Post by **N170BP** » Fri Oct 17, 2003 3:25 am

The aileron gap seals are (in my opinion) worthwile.

I would not install the flap gap seals.

Bela P. Havasreti

blueldr · Post by **blueldr** » Fri Oct 17, 2003 3:39 am

On a Cessna 170B, 172, 175, 180, 182. 185. or any with "Fowler" type flaqps:

Aileron gap seals= GOOD Increases aileron sensitivity.

Flap gap seals= BAD Decreases flap effectiveness.

Post by **GAHorn** » Fri Oct 17, 2003 4:27 am

While I'm not a fan of gap seals, (how would you ever get your money back on this item?) ... I would like to have answered why flap gap seals are "bad" and hurt flap performance? They only seal the gap while the flaps are fully up, right? So Fowler flaps,...or even semi-fowler flaps,... or even slotted semi-Fowler flaps like we have on our 170B's shouldn't be hurt (performance wise) by gap seals, should they?

N170BP · Post by **N170BP** » Fri Oct 17, 2003 5:17 am

The way I understand it, the aileron gap seals can indeed improve the
effectiveness of the ailerons by nature of the design (split hinge at the
upper surface of the wing). The effectiveness of a slotted Fowler flap
design however depends considerably upon air passing through the "slot"
as-it-were, and anything you install that blocks (to any extent) this path
of air starts to defeat the inherint characteristics/benefits of the
fowler flap design.

As far as getting you money back, I'm not so sure I'd reach into my
wallet to buy a set of aileron gap seals for my '54 if they weren't
already on the airplane when I bought it.... I flew a bone-stock '53 for
awhile and quite frankly, didn't notice a great deal of difference.... I
think the aileron rigging (cable tension, etc.) between airplanes would,
in itself, tend to make pilots think one airpalne (vs another) had "more effective" ailerons.

Bela P. Havasreti
'54 C-170B N170BP

N1478D · Post by **N1478D** » Fri Oct 17, 2003 2:08 pm

Why not just go ahead and put A model wings on instead. With the gap seals on, that's what you end up with on the bottom of the wing anyway.

Roesbery · Post by **Roesbery** » Fri Oct 17, 2003 4:44 pm

Back in 1978 I had flap gap seals installed, took the plane up to the same altitude and power setting I used on flying to the airport where they were installed, and had a increase of 4 mph in indicated airspeed. Never could tell any difference in any other aspect of flight.

Post by **GAHorn** » Fri Oct 17, 2003 5:42 pm

N1478D wrote: Why not just go ahead and put A model wings on instead. With the gap seals on, that's what you end up with on the bottom of the wing anyway.

Well, Joe, that ain't necessarily so. The B-model wing also has lots of available lift/drag from those large flaps, and improved aileron effectiveness from outer wing-panel twist, and stability-enhancing dihedral. Not many of the A model wings have that Vne twist-and-dihedral mod yours has.

N1478D · Post by **N1478D** » Fri Oct 17, 2003 6:02 pm

Was ABSOLUTELY certain that you would respond to that one!

Been seeing New and Improved on advertisement claims for new products and new models for a few decades now. It wouldn't be possible that a marketing department would claim something just to sell the new ones coming off the line would it? More stability? More lift? More drag? More effective ailerons? Guess you need a fairly sensitive meter to measure those things! Put an extra bean in a 100lb bag of coffee and sell it as new and improved for a year. Take two beans out next year and claim really new and improved and make more money for the next year.

Post by **GAHorn** » Fri Oct 17, 2003 6:33 pm

Yep, truth is the ragwing is the truly Classic airplane, and the A-models are all certainly fine machines. I wouldn't turn my nose up on any of them if I were in the market for an affordable and maintainable airplane that still has good support even after 50 years.

N1478D · Post by **N1478D** » Fri Oct 17, 2003 6:39 pm

Me Too! Any good 170 will do. Someone on here once said that they look at all of them at the flyins and airshows - they sure expressed my thoughts. Fifty years and still cookin, lookin good, and sexy as hell - sounds like my women!