Aerofoil change?

[Deskpilot]

I'm soon to start restoring my Thruster wings and as I'm putting in new ribs, I wonder if any of you can suggest a new or improved aerofoil profile? I'm not after supper fast or angelic climb, just a better weight lift if anything. Cheers in advance.

 

 

[facthunter]

Extra wing area would do that. or reduce drag /increase thrust. it's all a bit too much. Nev

 

 

[kasper]

The aerofoil on the nearly all the thrusters is pretty high lift so unless you are looking at an early T83/84 single seater without any lower battons you are better off just checking your battons agains the correct profile and then reducing drag as much as you are allowed.

 

In 'as much as you are allowed' I am really pointing out that if a two seater and its got 25- reg then you cannot legally change the aerofoil nor add much in the way of drag reduction unless thats already been CAR35 or equivalent approved unless you are prepared to wage war and spend money on the RAAus MARAP process.

 

If its single seat 10- reg then I'd still just focus on checking profile against the original and living with it.

 

Edit - ok - checked your posts and pics of your restoration you seem to have a nice looking T83 single seater. Without opening up the wing skins and sewing in new batton pockets you are going to be limited to the flat bottom section you have ... the T85 changed the wing to have more battons closer together and full lower battons so the section holds much better. Without doing a lot of redesign work to effectively put a new wing on the airframe you will be limited on what you can do.

 

The T83 will not climb really well at high weights because the lower surface of the wing will press up into the wing with the airpressure - you end up with an undercambered wing section thats lower lift than you would like - but it still climbs well enough - mine did and that was with my fat bum and a tired Robin 440 spinning an original plastic ultraprop

 

 

[Deskpilot]

Thanks guys. My thoughts so far:

 

Drag reduction, no open gaps between any flying surfaces and a very smooth and shiny epoxy resin impregnated faux silk skin to replace the coarse Dacron finish.

 

Better lift, new foam ribs with lower shape to replace the top only alli ribs. The skin can adhere to convex or concave shape so profile change is possible. Leading edge will be internally supported to eliminate scallops.

 

Kasper, the plane was originally grounded due to perished Dacron so no need to sew anything. I believe my plan will work out a hell of a lot cheaper than new skins($2-3K)

 

My wings will also be of the folding type so that towing and rigging is a one man operation.

 

So back to the original question, a new profile without changing the width (spar to spar)? Would a slightly convex bottom be of help?

 

BTW, it's 10- category.

 

 

[Bruce Tuncks]

In the olden days, they were surprisingly good about airfoils. I wouldn't change it.