That nasty AT-6 Bounce
#1
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That nasty AT-6 Bounce
i just finished up my byron AT-6 here about 3 months ago and now have 11 flights on it. I have flown giant scale stuff for years and have never seen a t-6 so bouncy . no matter how hard i try to land it on the mains ,it bounces back into the air , and i mean bad. i have just about run out of ideas on how to tame the beast . the CG is right on the numbers. the plane came in a 33 lbs. i thought it was over weight till i see just how forgiving it is. it's still a floater . i have all the flaps functioning and I've tried just about every landing configuration i could think off and it still bounces bad ! any thoughts? i was told to make it more nose heavy to putting expo in the elevator etc.
#2
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RE: That nasty AT-6 Bounce
I have always landed them full flap, hold a good amount of power and let is sink naturally. SOmewhere around 2 feet from the touchdown, ease the power out and start pulling a bit of elevator until the wheels touch. It has to be wheel landed, not three pointed. It also helps to suck up the flaps right after touchdown as it will allow the tail to drop quicker.
#3
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RE: That nasty AT-6 Bounce
Even if the CG is on the exact spot the mfg suggests, it is probably too far back and is the cause of what you're experiencing.
When it's too far aft of the "footprints" and those feet touch the ground, they push UP. The CG is headed DOWN and keeps on going if it can. When it's too far aft for it's momentum to be resisted by and absorbed by the gear, it pushes the tail down while the gear keeps the front up. And the plane bounces.
The way to find out if moving the CG would help and if it's safe to do move, run an application like geistware to find the safe CG range for the model. It takes a yardstick and about 5 minutes.
Find the CG range with the app. Then eyeball the angles possible from within the CG range to where your wheels touch the ground.
When it's too far aft of the "footprints" and those feet touch the ground, they push UP. The CG is headed DOWN and keeps on going if it can. When it's too far aft for it's momentum to be resisted by and absorbed by the gear, it pushes the tail down while the gear keeps the front up. And the plane bounces.
The way to find out if moving the CG would help and if it's safe to do move, run an application like geistware to find the safe CG range for the model. It takes a yardstick and about 5 minutes.
Find the CG range with the app. Then eyeball the angles possible from within the CG range to where your wheels touch the ground.
#4
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RE: That nasty AT-6 Bounce
It sounds like a real scale AT6
Have you watched any training videos for the AT6?
Zeno's is a good place to start. I had exactly this problem although it would vary from the bounce, or a ground loop, or try too hard and get a tip stall.
All standard AT6 characteristics.
The trick it seems is a 3 pointer, and that is what I found. After watching some pilot instruction videos on AT6 landing, I tried it on my model, and it worked.
Approach as usual, gear down flaps down, and at the flair hold off, with the plane in a 3 pointer attitude so that the mains and tail all touch together.
Worked every time I could manage it, and when I couldn't quite get it, ate least the bounces were not as bad.
I found flying it in on mains was OK until you tried slowing down, and as soon as the tail started to drop - ground loop
Good luck
Have you watched any training videos for the AT6?
Zeno's is a good place to start. I had exactly this problem although it would vary from the bounce, or a ground loop, or try too hard and get a tip stall.
All standard AT6 characteristics.
The trick it seems is a 3 pointer, and that is what I found. After watching some pilot instruction videos on AT6 landing, I tried it on my model, and it worked.
Approach as usual, gear down flaps down, and at the flair hold off, with the plane in a 3 pointer attitude so that the mains and tail all touch together.
Worked every time I could manage it, and when I couldn't quite get it, ate least the bounces were not as bad.
I found flying it in on mains was OK until you tried slowing down, and as soon as the tail started to drop - ground loop
Good luck
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RE: That nasty AT-6 Bounce
I have heard that this is also an issue with the full size AT-6 and the cause can be traced back to the center flap. There are a few full size flying around with the center flap bolted shut and this is supposedly the reason why.
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RE: That nasty AT-6 Bounce
I have been flying the Y/A T-6 for 10 years, and the big Petrausch T-6 for 2 years, and at first, I tried most of the above to tame the bounce. The three point looks good when you can pull it off, but you risk stalling the aircraft. There is one thing I found that works everytime.
If you land on the mains, under a little power, simply release the up elevator at the exact time the mains touch the ground and the plane will stick like glue. I also pull the flaps up and cut power as soon as it starts rolling and the tail will come down almost immediately. With the extra speed of the wheel landing, the rudder still offers control. As the tailwheel touches, I continue to steer with the rudder and have never ground looped. The tendency to bounce disappears completely.
I am not advocating a high speed landing here, just carry enough power to maintain control.
If you land on the mains, under a little power, simply release the up elevator at the exact time the mains touch the ground and the plane will stick like glue. I also pull the flaps up and cut power as soon as it starts rolling and the tail will come down almost immediately. With the extra speed of the wheel landing, the rudder still offers control. As the tailwheel touches, I continue to steer with the rudder and have never ground looped. The tendency to bounce disappears completely.
I am not advocating a high speed landing here, just carry enough power to maintain control.
#9
RE: That nasty AT-6 Bounce
ORIGINAL: Chad Veich
I have heard that this is also an issue with the full size AT-6 and the cause can be traced back to the center flap. There are a few full size flying around with the center flap bolted shut and this is supposedly the reason why.
I have heard that this is also an issue with the full size AT-6 and the cause can be traced back to the center flap. There are a few full size flying around with the center flap bolted shut and this is supposedly the reason why.
#11
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RE: That nasty AT-6 Bounce
ORIGINAL: Chip_Mull
As Diego Lopaz told me once...Justa as the wheels touch You leta go of the elevator. Just keep your eyes on the wheels on landing and make sure if you're holding up elevator on landing...Leta go.
As Diego Lopaz told me once...Justa as the wheels touch You leta go of the elevator. Just keep your eyes on the wheels on landing and make sure if you're holding up elevator on landing...Leta go.
If a guy can 3 point a at6 he's either got great timing or great luck,, or both
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RE: That nasty AT-6 Bounce
ORIGINAL: scale only 4 me
If a guy can 3 point a at6 he's either got great timing or great luck,, or both
If a guy can 3 point a at6 he's either got great timing or great luck,, or both
#13
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RE: That nasty AT-6 Bounce
i have been flying at-6's for 9 years . i just retired my old trusty midwest. that also had a tendency to bounce ,but nothing like this bird. i'm going first move the cg forward then try to move the mains back. a full scale has the gear almost straight down , the byron has them forward a lot. i treid the different power settings and flap settings and i'm also aware of the method of relaxing the elevator after the mains touch, the only problem is it's back in the air before i can relax. Gary Fitch our AMA Executive Vice President "who's also a close and personal friend of mine" said to me as i was struggling to get the landings right, that there wasn't anyone at that meet that wanted to be in my shoes lol
#14
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RE: That nasty AT-6 Bounce
ORIGINAL: Chad Veich
I land mine 3 point almost exclusively. In the spirit of full disclosure I have to admit mine does not have flaps and only about 1 in 3 of my landings is what I would call really good though! [X(] Actually, getting it on the ground nicely is generally not a problem, it's keeping it straight afterwards.
ORIGINAL: scale only 4 me
If a guy can 3 point a at6 he's either got great timing or great luck,, or both
If a guy can 3 point a at6 he's either got great timing or great luck,, or both
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RE: That nasty AT-6 Bounce
Hey Ron, I used to have a Harvard (Canadian), and wheel landings were mandatory. If the tail dropped too soon, then the angle of attack of the wing would make the beast fly again, but without sufficient airspeed to maintain flight, dropping the left wing and stalling. Once on the mains, level the elevator and let the speed bleed off and the tail comes down on it's own. Timing of course in 'relaxing' the elevator is important, and an old guy like you who just had a birthday is probably loosing it.....LOL
Most likely see you in Cuba and I can critique the landings.
Most likely see you in Cuba and I can critique the landings.
#16
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RE: That nasty AT-6 Bounce
As with any taildragger, full-scale or less, when doing a "wheelie", first it needs to be somewhat of a grease job, and second as has been mentioned, as the mains touch the aft stick has to be eased.
What's happening is that with a wheel landing, there is still some flying speed available. At touchdown, the CG being aft of the mains, the inertia tends to keep the CG moving downward. Since the mains are now on the ground, the angle-of-attack increases and the plane flies back into the air. It appears to be a bounce - and if the landing is firm, part of it is - but the main culprit is the rotation of the CG downward relative to the mains, and the resultant increase in AOA. The opposite happens in a nose-dragger: the CG, being forward of the mains, helps de-rotate the airplane after landing and take AOA off of the wings.
Typically then the plane starts crow-hopping, the pilot gets out of sync with the 'bounces', speed decays, directional control is lost. So, if doing a wheelie, come in kind of flat and 'skim' it on, ease the back stick to avoid any downward movement by the CG (maybe even a bunt on the stick), and let the tail settle as the speed bleeds off. For a 3-pointer, flare into the 3-pt attitude and let it settle onto the runway while increasing back-stick to hold the attitude. Since the tailwheel touches down along with the mains, there can be no CG moving/AOA increasing action, and the plane sits down on the ground nicely.
This works for me in full scale taildraggers and RC.
What's happening is that with a wheel landing, there is still some flying speed available. At touchdown, the CG being aft of the mains, the inertia tends to keep the CG moving downward. Since the mains are now on the ground, the angle-of-attack increases and the plane flies back into the air. It appears to be a bounce - and if the landing is firm, part of it is - but the main culprit is the rotation of the CG downward relative to the mains, and the resultant increase in AOA. The opposite happens in a nose-dragger: the CG, being forward of the mains, helps de-rotate the airplane after landing and take AOA off of the wings.
Typically then the plane starts crow-hopping, the pilot gets out of sync with the 'bounces', speed decays, directional control is lost. So, if doing a wheelie, come in kind of flat and 'skim' it on, ease the back stick to avoid any downward movement by the CG (maybe even a bunt on the stick), and let the tail settle as the speed bleeds off. For a 3-pointer, flare into the 3-pt attitude and let it settle onto the runway while increasing back-stick to hold the attitude. Since the tailwheel touches down along with the mains, there can be no CG moving/AOA increasing action, and the plane sits down on the ground nicely.
This works for me in full scale taildraggers and RC.
#18
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RE: That nasty AT-6 Bounce
To properly do a wheelie (wheel landing), you have to keep the speed up a little and just as the mains touch, push the stick FORWARD a little to plant the wheels on the ground and keep the tail up until it won't stay up any more, then you give it full UP elevator to keep the tail planted.
I bought a full scale Citabria in April this year and am having to learn how to land all over again. It's kind of like sex. Just feels great when you do it right, and you might get slapped if you do it wrong.
They say that if you can master the full scale T-6/ SNJ, you can handle the P-51, etc. It is not a forgiving "trainer".
Dale
I bought a full scale Citabria in April this year and am having to learn how to land all over again. It's kind of like sex. Just feels great when you do it right, and you might get slapped if you do it wrong.
They say that if you can master the full scale T-6/ SNJ, you can handle the P-51, etc. It is not a forgiving "trainer".
Dale
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RE: That nasty AT-6 Bounce
Owner of two Byron AT6. The only thing that stops the bounce is the stick forward trick listed above. Goes against your instincts but as soon as the mains touch give her a bleep of down input. Will stop the bounce and stick. Takes some getting use too.
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RE: That nasty AT-6 Bounce
It's the drop that makes it bounce. If you trim your plane so that it just barely loses altitude as you throttle down with retracts and flaps down, the plane should never drop fast enough to bounce. A long shallow approach is needed for this too but is works for me. Try making the strut springs a little lighter and mushier when compressed
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RE: That nasty AT-6 Bounce
Yep let go of the stick. That is the reason for the bunny hopping. You are still holding up elevator AFTER the mains touch. LET IT GO. Key thing is to do a day of touch and goes to get you use to the releasing of the elevator just as the wheels touch. It is a timing critical thing that you have to get use to. Only way to get there is by practice and touch and goes will get you there quickly. After doing a dozen or more landings in quick succession the brain start to get the program what to do.
#23
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RE: That nasty AT-6 Bounce
I have been flying a Ziroli AT-6 for the last year. I have had a lot of problems with bounces on landing, esp in windy conditions. I didnt build this plane and have moved the CG forwards a lot since it was almost unflyable in the original condition. This winter I will modify the flaps, they are only good for about 15 degrees so I have to cut back some wood to allow more travel. Thanks for everyones suggestions in this thread, helps a lot.
#24
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RE: That nasty AT-6 Bounce
another cause could be the fact that i have to much flap which only increases the ground affect problem . at 33 lbs i can't believe how much this thing still floats. wheel landings are a nice idea but until i can get the plane stability ironed out ,it's a mute point. i had a corsair that was very close to the same as the t-6 . i actually had to completely let go of the elevator stick or i would end up with the same thing. anyone ever move the CG forward? dave i feel your pain. one thing i forgot to mention is every flight has either had a firm headwind or a crosswind . something t-6's hate.
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RE: That nasty AT-6 Bounce
ORIGINAL: bookmaker
keep the speed up a little and just as the mains touch, push the stick FORWARD a little to plant the wheels on the ground
Dale
keep the speed up a little and just as the mains touch, push the stick FORWARD a little to plant the wheels on the ground
Dale