3 Point Attitude...

[builderflyer]

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I measure exactly 45" from ground to spinner tip. I can't measure the length of gear leg without removing stuff but it appears they could be longer than 18". When I built my airplane I cut the length of the titanium gear rods exactly per plan. I'm currently using a very worn 4" tailwheel but I'm also using a modified tailwheel fork which raises the tail end about 1".

Art,,,,,,,,,,,,,,,,,,,,,Sonex taildragger #95,,,,,,,,,,,,,,,,,,,,,,,,,Jabiru 3300 #261

[gammaxy]

I measured 45.5" from ground to spinner tip. Only trust this number to within about an inch since I doubt the ground is that level near my spinner. Measuring along the top of the gear leg to the axle socket is 18". It seems like the difference between the highest and lowest spinner mentioned so far is a little under 1 degree.

Here's why I don't think you're going to be able to find any noticeable increase in performance without huge changes in gear length:

A 2% increase in airspeed (about 1mph at takeoff speed) creates 4% more lift. If you want to create this lift without increasing speed, you need to increase the lift coefficient by 4% from around 2.0 (approximation based on clean stall speed and gross weight) to 2.08. A perfect wing has a lift curve slope of about .11/degree. On the Sonex, it is closer to .08/degree. You need about 1 degree extra angle to make a 1mph difference in takeoff/landing speed.

It's a shame the LAA is limiting your flaps. I think there's more performance to be gained there. I usually don't use flaps on takeoff, but with my Aerovee, 10 degrees makes a noticeable difference. Depending on whether you are trying to clear obstacles, or just get out of a short runway, I wonder if 20 degrees is reasonable with the 3300?

[avee8r]

My spinner is 44 3/16, measured on a good level floor. I can’t get to the gear leg, sorry.

I have the short flaps and my Sonex stalls right at the book value of 42 with full flaps. (I understand you’re flap limited by gov. Regulation) My speed over the fence is 53 (1.3 X Vso) and I get the sweetest tail wheel first, by just a moment, touchdown most every time.

Happy Landings
John
N50NX

[fastj22]

I tested a really slow 3 point landing last weekend (Gary Motley style). I have a lift reserve indicator and was flying just at the stall on approach, around 40 MPH, full flaps. Gary is the master of this. Sink was significant and I was adding power to make the threshold. The plane felt very spongy and just before touch down, the buffet of the stall. I bounced. Landed three point and the roll out was short. Carrier landing. But it wasn't the type of landing I would like people to see. Seemed forced. I've seen Gary do this perfectly, but I don't have his skills.
My perfect landings is an approach around 65 mph. Then attempt to wheel land but it ends up a three point (its just too slow to keep the tail up). If I want to do a nice wheel landing, I have to come in a lot faster, around 75 to 80. At that speed, you can keep the nose down and fly the tail until the speed bleeds off.

[caveman370]

I tested a really slow 3 point landing last weekend (Gary Motley style). I have a lift reserve indicator and was flying just at the stall on approach, around 40 MPH, full flaps. Gary is the master of this. Sink was significant and I was adding power to make the threshold. The plane felt very spongy and just before touch down, the buffet of the stall. I bounced. Landed three point and the roll out was short. Carrier landing. But it wasn't the type of landing I would like people to see. Seemed forced. I've seen Gary do this perfectly, but I don't have his skills.
My perfect landings is an approach around 65 mph. Then attempt to wheel land but it ends up a three point (its just too slow to keep the tail up). If I want to do a nice wheel landing, I have to come in a lot faster, around 75 to 80. At that speed, you can keep the nose down and fly the tail until the speed bleeds off.

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[caveman370]

I tested a really slow 3 point landing last weekend (Gary Motley style). I have a lift reserve indicator and was flying just at the stall on approach, around 40 MPH, full flaps. Gary is the master of this. Sink was significant and I was adding power to make the threshold. The plane felt very spongy and just before touch down, the buffet of the stall. I bounced. Landed three point and the roll out was short. Carrier landing. But it wasn't the type of landing I would like people to see. Seemed forced. I've seen Gary do this perfectly, but I don't have his skills.
My perfect landings is an approach around 65 mph. Then attempt to wheel land but it ends up a three point (its just too slow to keep the tail up). If I want to do a nice wheel landing, I have to come in a lot faster, around 75 to 80. At that speed, you can keep the nose down and fly the tail until the speed bleeds off.

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Oops
I have the Flyboy tail wheel as John does.
My tail sits a tad higher. I do like it because I can see over the nose at 3 point attitude.
I seem to be in the area of 65 to 70 and let it settle on. I haven’t noticed any longer ground roll either


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[Ad Eves]

Thanks all.

I guess I'll do some more experimenting to figure out the best short field technique for my aircraft just accepting the tail-first landings. I will also have a discussion with our LAA to see if they will allow me to experiment with the factory full-flap setting when I do the aerobatic flight test programme.

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[flyingbear]

I have hundreds of hours in a Thatcher CX4 and over 1000 in a Cassutt. Both need more angle of attack on the ground for short takeoff or landing. My Cassutt would lift off at 120 mph 3 point when I got it. I added 5 inches to the gear and got that down to 100 mph.
The CX4 will hit tail first any time it is anywhere near a stall. I do not like that but it does mean the aircraft stays planted better for low time pilots.
Glen Bradley