Speed Mods - Flap Gap Seals - Safety

[labbadabba]

So, looking at LoPresti and Knot4U speed mods just because I have nothing better to do with my life.

Question about some of these mods, in particular gap seals. These appear to be plastic/fiber glass fairings that attach to the wing and smooth out the airflow around flaps, elevators, and ailerons. I get why this would be a good thing.

However, they do seem to me like they might potentially interfere with the movement of the control surfaces. As they age, they may stiffen and become brittle. I know I've read of at least one instance where a gap seal has jammed a flight control surface. How big of a problem is this? Is it more risk than what it's worth (i.e., 5-7kts in cruise and 3kt reduction in stall speed)?

 

[steingar]

I had tape flap gap seals in my Cherokee. They didn't interfere with anything.

 

[Loveair]

I have flap gap seals on my 182. They are metal. And really reduce the stall speed. And probably increase the cruise speed a knot or two.

 

[timwinters]

I installed flap gap seals on my 182 last year at annual. Like @Loveair said, they are metal (aluminum actually) and they may add just a few knots.

I installed them mostly because I like the way they look and because I was reskinning my flaps too. But most importantly, I didn't think I had near enough screws to R&R at each annual and wanted about 100 more!

 

[BigBadLou]

Gap seals should not interfere with anything but stray air flow which they are supposed to stop.
I understand your skepticism, it is healthy in small doses. That's why you do a proper preflight check and verify that all control surfaces can move freely with no interference.
Gap seals are a good bang for the buck because they increase the efficiency of the lifting surface at minimal added weight and drag.
As long as your mechanic installs them properly, you should have 0 trouble. It's not like the spanner wrench that was lodged in the flaps.

 

[labbadabba]

So what's a better bang for the buck? Gap Seals or Wheel Pants/Fairings?

 

[hindsight2020]

wheel pants and nosewheel fairing. But not the crapola OEM ones, I'm talking about the ones that blend into the strut and streamline it.

Go take off the pants on RVs and a Cirrus or Columbia, and report back their cruise numbers. The decrease would be unacceptable to their owners.

 

[frfly172]

I put the gap seals on my 172,took a little getting used to. Really lowered the stall speed. Didn't add much on speed.

 

[steingar]

Lotta airplanes don't look right without wheel pants.

 

[labbadabba]

What about cowlings? Why isn't there a mod out there for a PA-28 cowling? (Arrow not included...) Seems like the Cherokee cowlings are pretty gnarly, you'd think as ubiquitous as the Cherokee is that there would be a decent cowling upgrade out there.

 

[Hank S]

Lotta airplanes don't look right without wheel pants.

The best looking wheel pants are short pants . . .

 

[Jim_R]

So, looking at LoPresti and Knot4U speed mods just because I have nothing better to do with my life.

Question about some of these mods, in particular gap seals. These appear to be plastic/fiber glass fairings that attach to the wing and smooth out the airflow around flaps, elevators, and ailerons.

I have the Laminar Flow Systems flap and aileron gap seals on my Cherokee. The performance change at low speeds was dramatic--there is far more roll control authority. The plane also climbs better with them. I'm not sure about any cruise speed improvements, but I'm sure I didn't lose anything there.

Here's video of the roll control difference before/after LFS gap seal installation:

 

[dell30rb]

What about cowlings? Why isn't there a mod out there for a PA-28 cowling? (Arrow not included...) Seems like the Cherokee cowlings are pretty gnarly, you'd think as ubiquitous as the Cherokee is that there would be a decent cowling upgrade out there.

What I really wonder about is the comanche. The PA-28 cowlings are no LoPresti product, but they don't look too inefficient.

 

[Checkout_my_Six]

best speed mod.....buy a faster plane.

 

[timwinters]

best speed mod.....buy a faster plane.

Actually, the best speed mod is to add long range tanks if you don't already have them!

 

[labbadabba]

What I really wonder about is the comanche. The PA-28 cowlings are no LoPresti product, but they don't look too inefficient.

LoPresti has cowlings for the Comanche and Twin Comanche. They are things of beauty.

 

[labbadabba]

What I really wonder about is the comanche. The PA-28 cowlings are no LoPresti product, but they don't look too inefficient.

I'm no whiz when it comes to aeronautical engineering but this cowling to me says: "needs improvement"...

 

[dell30rb]

No doubt it needs improvement, but its better than the comanche

 

[labbadabba]

No doubt it needs improvement, but its better than the comanche

Mmm, sexy: