Improving short field peformance on no-flap short wings

[6PapaWhiskey]

I'm looking at installing VG's on my Wagabond for better short field performance. I'd like to get the landing distance such as to comfortably and consistently get into a 900' grass strip with obstacles. Even if that ends up too short, I'd like to lower the landing speed a bit. Alabama is mostly pine forests and lower landing speeds would increase survivability in case of a forced landing. VG's on the wings seem to be the answer as far as getting the stall speed a bit lower and improving roll response. One issue I experience at times is loss of elevator effectiveness in the landing flare at idle power. Some VG kits come with some for the horizontal stab. I'm also aware of the tail gap seals for available from CubCrafters.

I'd like to hear from those who own or have owned no-flap short wings about their actual experience as to which brand of VG worked for them and the performance difference that they experienced. Additionally, I like to hear from them on whether VG's or gap seals work better on the horizontal stab, and if they found any need for gap seals on the vertical tail.

Tom P.
N476PW
Wagabond @ 08A

[SMO22]

I think you are overlooking the single most effective thing that can significantly reduce stall speed, these are like putting a parachute on the wing, a huge reduction in induced drag, with that the vertical lift componant is increased which makes lift equal weight at a noticably lower airspeed.
The bow tip is removed, spar lengthened and another rib added and than the plane booster wing tip put on.
http://store.cubcrafters.com/Plane-Booster-Wing-Tip-Set-_p_1859.html
https://i.imgur.com/2cctg3a.jpg

[andya]

My vag is heavier that most at 750+ empty. It has two 12 gallon wing tanks + the fuselage tanks (36 gallons)
full and someone my weight is definite over gross. Extra weight comes from pilot side door, wing tanks, 85 hp.
I have VG's and it really doesn't stall, it just starts sinking. With the fwd cg due to engine and other, a full
power off landing will have to touch down a little faster because I loose elevator authority on the flare.
Power on till almost touch down provides airflow so you don't loose elevator authority and it is easy
to touch down slower and hit tailwheel first. Often thought about putting weights in the back to move the
CG back and examine how it would handle in power off landings but never have the time to experiment.

[d.grimm]

The I was always looking for the best way to shorten takeoff and landing distance
For my C85 powered Vagabond.
You have many advantages being Experimental.
My notes are long gone it these are the things I did to use my cousins
700 ft no obstacle strip
1. I put 25x11x4 tires to increase angle of attack.
Angle of attack for stall on Vagabond airfoil at 14 degrees
Tires and small Scott 2000 Tailwheel gave me just about 14 degree AOA.
2. Gap seal on elevator hinge line.
3. Ailerons rigged for slight drop.
4. Gurney flaps on wing and wing fairing trailing edge. 5/8 is what I determined, never tried.
5. My Vagabond had dual wing tanks and no nose tank so CG was more aft, way within limits.
6. Wood Sensenich W72GK44, light and could get max RPM (within TCDS limits)

500 ft was easily achieved after a little practice, takeoff and landing used the same distance (expander tube brakes)
Dave

[d.grimm]

Never answered the VG question, oops.
Unless you get more AOA on the ground I don’t see VG’s helping anything.
Dave

[rideandfly]

Don't have VG on my Vag. At 65MPH IAS on final approach at 1000 pounds (1150lbs gross), the Vag floats during flare. Currently working on landing shorter with slower approach speeds.

Here's a thread discussing Vag VG and approach speeds:

http://www.shortwingpipers.org/forum/showthread.php?7901-Vagabond-Landings&highlight=landing+vagabond

[tnowak]

Hi Bill,
Is your engine idle RPM set correctly at around 550 RPM?
I rarely get float at all when I trim and approach at 65 MPH.

Try approaching at 63 MPH. At 60 MPH I find you have to react quickly on the roundout.
TonyN

[Steve Pierce]

My shortest landings in the Clipper were in a hard slip using power, no VGs or elevator gap seals.

[rideandfly]

Hi Bill,
Is your engine idle RPM set correctly at around 550 RPM?
I rarely get float at all when I trim and approach at 65 MPH.

Try approaching at 63 MPH. At 60 MPH I find you have to react quickly on the roundout.
TonyN

Tony,

Good point!

Idle is around 550RPM. The Vag has a CM 71/46 metal propeller with C-85, FAA field approved installation. Aircraft Spruce information I've read about this propeller, it's a cruise propeller on a C-85 powered J3. Will try 60MPH approaches. My AS indicator may be reading a little low, too.

Will also try slipping with power, after seeing places Steve lands his Cub are very impressive to me.

Having plenty of fun learning about landing a tailwheel airplane without flaps. :D

[6PapaWhiskey]

Thanks to all for the suggestions. The wingtips are a bit more than I care to invest for this effort. I didn't note any quantifiable improvements for VG's & gap seals so I think that I'll leave things as is for now. I've decided to order a new Vetterman exhaust which will consume my aviation spending for the time being. Annual and insurance renewal will be next.

Tom P.
Wagabond @ 08A