zadwit

Here is an interesting video circa 1938 about flat , uncambered and streamlined air foils. IF you look at the flat or undercambered airfoil, at high angle of attack the airflow seperated pretty far forward on the wing. This is why it is important to get the VGs up front, if too far back they are in "dead" air and cant do any good. I think Trent said 4% of the airfoil which I think is only 2" aft of the wing leading edge...
Also the undercambered airfoil has more drag than most airfoil even at 0 angle of attack. I guess they work on really slow very low powered airplanes but as kitfoxs amd avids got bigger and bigger engines, it reared its ugly head as a drag producer... one last thing and I am not sure it is talked about here but thin undercamberd airfoils can exhibit nasty stall characteristics without any aerodynamic warning......in fact I have read lots of accident reports , "I was in a 45 degree bank at 50 mph with 2 on board and it stalled"
ANyway I thought the video was of interest to all here. IT also shows how slats work...

I just installed a new Matco 8" tailwheel on my model 4. IT has cams that only release at 45 degree angles left and right... I have a set of cams that release at 25 degrees. WHich ones should I use??????? THanks

I had this plane sold and just wanted to do one last flight..The forecast was for calm winds and when I showed up at the airport it was calm. I have the coil spring "Hatz" type shocks which bottomed out and bent the left gear. YOu can see in the video towards the end if you look down at teh left gear leg it is bent from my hard landing....
I went out and flew around for about 20 minutes instead of just around the pattern.. when I came back the (1)wind had picked up to about 20 mph from the right direct cross wind.
(2) I had installed one size smaller idle jets to smooth out the idle just a little and it idle smooth at 2200 on the ground. I forgot that in the air, the prop unloads so I could not get the engine to come below 3300 in the air on landing. This was a surprise to me.. So on the first landing attempt I landed long and the plane just didnt want to slow down so I went around for worry about running off the end of the runway...I guess I should have shut the engine off but it all happend so fast I dont think that fast...(3) on the second attempt to land I let the wind blow me across the runway on downwind leg and yet I continued to salvage the landing,....I didnt know what was going on with the throttle, thoughts of the housing slipping off or the engine goign to idle by  itself crossed my mind so I was determined to LAND.(4) my airspeed is a POS and hard to read. If you look, you will see the airspeed get dangerously slow as I get close to the ground... The airspeed bleeds off rapidly from 45-35mph and I knew this but I was trying to slip and towards the end do a skidding turn to line up with the runway....I ended up stalling out about 5 ft in the air and hit hard, hard enough to bottom the coil sping on the left gear and bend the gear leg. The the wind turned me to the right  and onto the ditch... I have 6.00-6 tires so they do not soak up much landing shock. If I had tundra tires I might have not hurt anything...
I know the key is a stablized approach and I did not do that... I should have gone around again and gone out farther and set up a longer final approach and a stablized approach...I just got behind the plane because they are quicker than most spam can planes and even pipers...we all flew at one time. being light weight they have low inertia so you have to pay attention to speed reduction, they happen quick.
I fixed the tail and the left wing tip and ordered the parts to fix the gear leg then just sold the plane.....38 yrs of flying and 3300 hours never bent a plane till this... but I look at the video and I see all the mistakes I made.....hopefully it will help others not do the same..
 
Oh , one last confession... my brakes are crap, I orderd new pads but they had not shown up when I flew it and I also have that damn Maule tailwheel and I felt it "Pop" as the ground loop started and the tail took a good side load the tailwheel "released"... POS, anyway... dont think much of them.... there are posts on this site on how to remove the cam so they dont unlock...

sold
 

 
 
 
 
 

I removed my bungees, the look like new and installed grove landing gear. Later I looked at the bungees closer and notices all the rubber strands are broken right next to the aluminum crimp. A landing or two later and it would have let go. These bungess are about 5 yrs old, plane has always been stored inside, total time about 150 hrs since new.
ENclosed are photos...
I think if I were making bungees, I hand make them and avoid the aluminum crimp.

sold