Whats the deal with flap gap seals?

B

BonanzaDriver

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BonanzaDriver
Just wondering if anyone has first hand, before and after, experiences with flap gap seals.

If I can gain 6-8knots for 500$, I am all over it.

Also, there was a company called Smith Speed Conversions that I keep hearing about from fellow bonanza owners/old timers. The claim is that this company produced mods that gave the bonanzas 25 knot cruise speed increase due to the reduced parasitic drag. (I am skeptical) I have searched and searched and cannot find anything.
 
Don't know about a Bo, but in a Piper Lance flap gap seals primarily improve low-speed handling. They do give a negligible (2-3-knot) cruise speed increase, but the low speed handling is the biggest gain, followed by a slighly improved rate of climb.
 
I didn't notice much top end from the gap seals, but I can fly below the bottom of the white arc with no flaps in my Cherokee.
 
BonanzaDriver said:
. The claim is that this company produced mods that gave the bonanzas 25 knot cruise speed increase due to the reduced parasitic drag. (I am skeptical) I have searched and searched and cannot find anything.
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Thats quite a claim! I'd be skeptical too.
 
Steve, you sure remember a lot of minutiae!

Impressive!
 
BTW, I was told by previous owner that my Cessna 150L cruised at 112mph before the complete STOL kit (including flap gap seals); And it now cruises at 117mph. (And will slow fly near 35!)
 
I have them on my Cherokee. The previous owner put them in. 2-3kts improvement in airspeed. That along with my wheel pants, 5 kts improvement in AS, my wing root flap seals also 2 kts improvement in AS, and I cruise at 130kts!!

Of course not I still cruise at about 115 to 120kts. I see a bigger change in AS with loading and with waxing. I am sure those things help but they do not add up on top of each other.
 
Well, I just happened have the chance to park the first PropJet prototype (Piper Malibu conversion) at Sun n Fun when it was staging to do its fly-by demo back in the 80's. Talked to the pilot for a bit. First plane I ever got to back into its spot under its own power! :)

The rest was Googled ;)

A prior Soloy conversion used an Allison 450hp turbine before PropJet got in the business.

Dr. Bill said:
Steve, you sure remember a lot of minutiae!

Impressive!
Click to expand...
 
gap seals are standard and have been for a long time in sailplanes. enterprising individuals have been known to use venetian blinds to cover the gaps in ailerons,flaps, elevators, rudders.
 
BonanzaDriver said:
Just wondering if anyone has first hand, before and after, experiences with flap gap seals.

If I can gain 6-8knots for 500$, I am all over it.

Also, there was a company called Smith Speed Conversions that I keep hearing about from fellow bonanza owners/old timers. The claim is that this company produced mods that gave the bonanzas 25 knot cruise speed increase due to the reduced parasitic drag. (I am skeptical) I have searched and searched and cannot find anything.
Click to expand...

Not a chance. A knot or two, at best.

I put them on the Commander a year before I put on the vortex generators. They help with the low end a bit, and add maybe a knot or two at the top. The VGs did much more for the low end handling than the gap seals.
 
My Twinkie has them, part of the Robertson conversion. As Ken noted, they seem to do more for low speed handling than speed.

Jay
 
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