Top Flite T-6 ?

Just like the Bonanza. Here for a while, gone for a while, back for a while, and gone again ! ! ! No rhyme or reason I could see.

David

Dennis:

I asked the same question of a supplier awhile back. His response was that the AT-6 and the "Hollywood-Zero" were discontinued as there was some poor flying issues with them. I found that interesting as I had a TF AT-6 that was a real dog in the air. It would snap roll in a heartbeat. I totaled it on a deadstick landing when it snap rolled 8 ft above the runway. During the course of owning this "pig" I had posted several requests for info on this problem on this site. The general response was that the elevator had too much throw and should be reduced to 1/8" up and down. While this prevented snap rolls it also prevented anything aerobatic, loops included. Now after said this I am sure that there will be a multitude of people saying this was the best plane they ever had.

discontinued.

Ahhh: Thats waht I wanted to hear: The reason for this post was the fact I also suffered a snap roll on landing about 8 feet above the runway, I though, Radio Problems ?? or did I just flat stall it: Weel I rebuilt it, its been sitting for a few years, I just put a new radio in it and gusee what, Took off got about 4 or 5 feet and WHAM snap roll, well I chucked it this time. I was just afraid it was due to my poor flying, although I have plenty of experience in high performance aircraft.

Denis Winters <

Did you have any washout in the wing?

Did you have any washout in the wing?

what possible good would washout have on take-off? washout is supposed to allow the inboard part of the wing to stall before the tip - not a real consideration while taking off. in advertant snap on take-off can be from an aft CG, or way way too much elevator. otherwise the plane is crooked.

Uh, excuse me? Tip stalls frequently occur on takeoff and landings. Wash-out will definitely help. You are absolutely correct in your analysis of other causes though! Too much elevator is probably the most frequent cause. I always set up minimal elevator on the low rate for initial flights. Then with plenty of altitude, I switch on the elevator high rate and see what happens. If it snaps, I know to dial back the high rate. After a lot of experimenting at high altitudes, I then can set up the aircraft to behave properly!

Wash-out definitely does help though.

jim:

we'll have to agree to disagree. i have been flying power for over 15 years, all sizes, .40 to 150cc and i can count the number of "tip stalls" i have seen on take-off on one hand. as long as there is sufficient airspeed over the wing, with or without washout doesn;t make any difference. an airplane that is horsed off the runway too fast may snap because the wing isn't flying, and while it looks like a tip stall, the whole wing is stalled. even still, this condition is going to be limited airplanes that have minimal wing area, tend to be heavily loaded, and have wings that have poor load speed performance, and may be underpowered or improperly propped - yes - there is such a thing. it is also more common on smaller planes of the .60 and small variety. i also fly scale gliders, (see Dec RCM) and every one has washout. gliders fly right above stall speed, and with the high aspect ratios too much down aileron could stall the tip. so we use a lot of differential and have negative incidence toward the tips - also called wash out. But wash out has very little application in power, where the flying speeds are higher, and the low aspect ratio wings with thick airfoils are far less susceptible to low speed stalling. it also ruins aerobatic performance. as far as landing, the classic landing snap is turning upwind and simply not having enough energy behind the airplane. the pilot feeds in too much elevator, and over she goes."tip stall" becomes the curse, but i doubt on 99% of these crashes wash out would have made any difference. it's pretty easy to watch someone on approach get ready to lose an airplane - the airplane gets mushy, the nose comes up, and boom. speed is everything.

I disagree. The transition from rolling on the ground to flying through the air goes through the stall speed at some point. A landing should occur exactly at the stall speed. As the plane slows, the washout helps prevent the tip of the wing from stalling first, a problem at ANY speed. On takeoff, as the plane accelerates, the washout gets the wingtips flying first, so again to help prevent the tips from stalling first at low speeds.

Tip stall, in any attitude, at any speed, under any conditions is not a good thing. Dr.1 Driver "There's a Hun in the sun!"

Dr, so according to you, an airplane rotates at close to its stall speed, and approach should be done at stall speed? well, I am pretty sure you don't have a full size ticket! FYI, and airplanes passes through stall on the GROUND during takeoff, and while contact is best done with the stall warning blaring, you sure as hell don't want to hear it on approach!

No, and I don't need one to know what flys and what doesn't. An airplane takes off past stall speed, sure, but not much past it. If it's stalled, it's on the ground (or soon will be). If it isn't, it's flying or it's a winged automobile (you're holding it on the ground with the elevator). An ideal landing (when the wheels touch) should occur at the same moment of stall.

You have yet to refudiate my comment that washout DOES help at ANY speed. Prove that with your "full size" ticket. Remember, though, when you scale down to a model, certain physics parameters don't scale down. Oh, BTW, just how much aerodynamics IS taught to get a pilot's license now-a-days? Dr.1 Driver "There's a Hun in the sun!"

Addendum: I've been in a small, very heavily loaded, single engine, 4 passenger plane on a short runway. We gradually accelerated down the centerline, full throttle. The end of the runway neared, and the pilot hauled back hard on the wheel. As we cleared the boundary fence by about 20 feet, the stall warning horn was screeching like a banshee. Obviously, we made it. Dr.1 Driver "There's a Hun in the sun!"

WOW!!! lokk what I started: Geesh !! anyway: YES there is washout built in. However this plane was just never right. It snaped on two occasions: first time on landing right over the numbers: had about a 5 deg. nose down attitude: six to seven feet from the ground and BAM! snaps. I have been flying full size as well as R/C since 1977 (I also am certified for aerobatics) from my point of view it was a simple case of letting a high performance aircraft get too slow: My point in relating the experience I have is the fact I know better than to EVER let that speed get too slow. Second snap was a few years later (after the rebuild) the plane got airborne before I even got the tail off the ground, I wasnt concerned as it was only maybee 10 deg. nose up, it didnt seem excessive. It was probably 8 feet up when BAM! snapped to the right. Again it "Looked" to be the classic stall, should have pushed the nose down, but not being inside the plane it just did not have the look of being too slow or too high of an angle of attack;

That said: I started getting courious why this plane was taken off the market after about a year: all the others from that warbird group are still being produced

I would like to think it was NOT pilot error: We just may never know ????

Denis Winters <

Dr., generally speaking you're correct, however one does not fly an approach nor land "at" stall speed. There's always a fudge factor in there, usually several percentage points worth. For example if an airplane stalls at 55 kts, one would normally fly the final approach at 60 kts + and touch down at (or slowing through) 60 kts.

Takeoff would be at 60 or above but few pilots would take off right at the 60 mark unless it were a short field. Taking off while hearing the stall warning is nothing short of suicidal, unless one is familiar with the plane and knows for a fact the stall warning goes off well above the actual stall. Pilots of full sized planes get themselves (and their passengers) into "situations" at times and in most cases, pull it off. When they don't, you read about it in the paper.

Your statement about tip stall is right on the money and most of the time, is cured by wash-out. Cheers, jc