Top-Flite Giant Corsair Airworthy!
07-12-2002, 08:39 PM
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Top-Flite Giant Corsair Airworthy!
Tuesday was the day. East Bay Radio Controllers field, Livermore, Ca. George on the sticks (AMA number in the low teens)
SHE'S A DREAM!
Lift-off was in about 45 feet. She was only on the mains a second before lifting perfectly wings-level into the sky. George then accidently hit the flaps instead of the gear and we gained about 100 feet really fast. I stopped shooting the video long enough to help him retract the flaps and get the gear up, and we were happening!
The low pass was outrageous. Gear up, full throttle, she flys nose low as if leaning forward on her wing for better speed. Her rudder was the only bugaboo, visibly vibrating on the pass, and we elected to bring her in. George elected to come in flaps-up and on the power, which was convenient because we did not want to mess with the rudder too much low and slow. The wind cooperated with a dying down to 3-4 kts and down the centerline. She looks awesome on final, even without the flaps, and even from the camera angle, I could tell that George was flying her easily, and that she will be very stable with flaps.
She came in hard. She flared in ground-effect and tried to porpoise a bit, but the springs in the Robarts were perfect for the weight, and she settled on after the second bounce. Taxi back was so beautiful, now that she'd been in the air. My heart was racing.
I want to shout out big props to Craig Goleta, who drew this model. I have never had a more rewarding build, and he even answered a few questions and allayed my fears about the US 41.
For all of you out there who have or seek this kit, the 41 is OK. I had people saying I was nuts and that ....blah, blah, blah. I'm flying the 41 with a wa144 carb, velocity stack, and Bennett muffler, and she pulls FINE! This plane will never do 3D, with any motor. Why go twice scale? I just can't fathom. This plane is FAST. Low pass was about 3-4 seconds from horizon to horizon. Did NOT need full throttle to fly great. Did not shimmy on approach, and I could hear George using the power inbound. Nice and solid.
Don't get me wrong. The guy flying is EXPERT. I'm not trying to say that the Corsair is docile like a trainer. But she is solid and unwavering in the air. Ailerons on low rate the whole flight.
So, anyone who wants info on this bird, I'm now in possession of one that flies, and I'm straight to Tower to get another one!
greg
SHE'S A DREAM!
Lift-off was in about 45 feet. She was only on the mains a second before lifting perfectly wings-level into the sky. George then accidently hit the flaps instead of the gear and we gained about 100 feet really fast. I stopped shooting the video long enough to help him retract the flaps and get the gear up, and we were happening!
The low pass was outrageous. Gear up, full throttle, she flys nose low as if leaning forward on her wing for better speed. Her rudder was the only bugaboo, visibly vibrating on the pass, and we elected to bring her in. George elected to come in flaps-up and on the power, which was convenient because we did not want to mess with the rudder too much low and slow. The wind cooperated with a dying down to 3-4 kts and down the centerline. She looks awesome on final, even without the flaps, and even from the camera angle, I could tell that George was flying her easily, and that she will be very stable with flaps.
She came in hard. She flared in ground-effect and tried to porpoise a bit, but the springs in the Robarts were perfect for the weight, and she settled on after the second bounce. Taxi back was so beautiful, now that she'd been in the air. My heart was racing.
I want to shout out big props to Craig Goleta, who drew this model. I have never had a more rewarding build, and he even answered a few questions and allayed my fears about the US 41.
For all of you out there who have or seek this kit, the 41 is OK. I had people saying I was nuts and that ....blah, blah, blah. I'm flying the 41 with a wa144 carb, velocity stack, and Bennett muffler, and she pulls FINE! This plane will never do 3D, with any motor. Why go twice scale? I just can't fathom. This plane is FAST. Low pass was about 3-4 seconds from horizon to horizon. Did NOT need full throttle to fly great. Did not shimmy on approach, and I could hear George using the power inbound. Nice and solid.
Don't get me wrong. The guy flying is EXPERT. I'm not trying to say that the Corsair is docile like a trainer. But she is solid and unwavering in the air. Ailerons on low rate the whole flight.
So, anyone who wants info on this bird, I'm now in possession of one that flies, and I'm straight to Tower to get another one!
greg
07-12-2002, 10:11 PM
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Top-Flite Giant Corsair Airworthy!
Yes, and hard to pinpoint, since I did the double whammy of not QA'ing a closed system before proceeding and using less than top-notch servos. I've got a little lash in the servo gears, a little flexxing at the rear control rod sleeve connection to the F10 former, and a little slop in the rudder torque rod sleeve. It all adds up. I'm stumped as to how to fix it without surgical entry to the empennage. Craig?
Building one? Mock up the rudder linkage before closing the empennage and kill the slop. Taht meand building the vert fin and temping it in to the notch in the former, but DO NOT Go BEYOND THIS STEP until that sucker is stiff and tight. I thought it was, but no. The little ply braces in the plan are not up to the task of securing the torque rod sleeve under vibration.
greg
Building one? Mock up the rudder linkage before closing the empennage and kill the slop. Taht meand building the vert fin and temping it in to the notch in the former, but DO NOT Go BEYOND THIS STEP until that sucker is stiff and tight. I thought it was, but no. The little ply braces in the plan are not up to the task of securing the torque rod sleeve under vibration.
greg
07-13-2002, 01:19 AM
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Top-Flite Giant Corsair Airworthy!
I did the 60 size so I know what you are talking about. My friend is getting to do the big one and that's why I asked. I get this feeling that I will end up doing a lot of it some where down the line. I hate enclosing the linkage like that!!!!
07-13-2002, 02:10 AM
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Top-Flite Giant Corsair Airworthy!
It's always great when a warbird flies successfully! Wish I coulda seen it! I'm curious, what does it weigh and how did it balance?
07-13-2002, 03:27 PM
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Top-Flite Giant Corsair Airworthy!
She tips the scale at 25 pounds 4 oz, dry and balanced.
I have a Stan's cowl, which is fiberglass, mated to the ABS flange that came with the Top-flite cowlette, which has itself been reinforced with strips of Kevlar and fiberglass. The balancing weight is 1/4oz stick-on wheel weights from the tire shop up the street.
When I first mocked her up to check balance, I was attaching the temp weight to the firewall, and added nearly 2 lbs. But when I went to really attach the weight, I hit on the notion of securing it to the cowl instead of the firewall. About 4-5" more datum for the weights, and it only took 24oz. I went for exactly 5-3/4 from LE, per the plans, on a Great Planes CG machine.
Whether it's the airfoil, the engine mods, the weight savings, or what, I don't know, may some of each. But she was off the ground in 45 feet (measured it yesterday), and flew the test routine with authority. George (the guy who flew her) said she was perfect. We added three clicks of down trim, and didn't touch the ailerons. Low rates flew the plane great.
Let me mention, for those who've not built big like this, something that I'll now never forget: Lateral balance. Things can get lop-sided really fast with giant wing-tip blocks, shear webbing, ply, glue, etc. My tip blocks as delivered were twenty grams (3/4oz) different, and at three feet from centerline, which one goes on which tip can make your day. Balance the wing frame at each building stage. Don't add weight, but think light toward the heavy side. Hard to determine? You're doing good.
greg
I have a Stan's cowl, which is fiberglass, mated to the ABS flange that came with the Top-flite cowlette, which has itself been reinforced with strips of Kevlar and fiberglass. The balancing weight is 1/4oz stick-on wheel weights from the tire shop up the street.
When I first mocked her up to check balance, I was attaching the temp weight to the firewall, and added nearly 2 lbs. But when I went to really attach the weight, I hit on the notion of securing it to the cowl instead of the firewall. About 4-5" more datum for the weights, and it only took 24oz. I went for exactly 5-3/4 from LE, per the plans, on a Great Planes CG machine.
Whether it's the airfoil, the engine mods, the weight savings, or what, I don't know, may some of each. But she was off the ground in 45 feet (measured it yesterday), and flew the test routine with authority. George (the guy who flew her) said she was perfect. We added three clicks of down trim, and didn't touch the ailerons. Low rates flew the plane great.
Let me mention, for those who've not built big like this, something that I'll now never forget: Lateral balance. Things can get lop-sided really fast with giant wing-tip blocks, shear webbing, ply, glue, etc. My tip blocks as delivered were twenty grams (3/4oz) different, and at three feet from centerline, which one goes on which tip can make your day. Balance the wing frame at each building stage. Don't add weight, but think light toward the heavy side. Hard to determine? You're doing good.
greg
07-14-2002, 12:35 AM
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US41... BUT.. Modified
Greg, I remember and even participated in the threads a few months ago concerning the US41. I still stand by what I said, about a STOCK us 41.
Bumping up the carb to the 144 with a velocity stack and running a B@B exhaust manifold (can't call it a muffler) is getting you probably 1000+ RPM's that anyone who tries to use the stock version doesn't get. And that is a HUGE difference.
Good job and I'm glad it worked out for you.
Bumping up the carb to the 144 with a velocity stack and running a B@B exhaust manifold (can't call it a muffler) is getting you probably 1000+ RPM's that anyone who tries to use the stock version doesn't get. And that is a HUGE difference.
Good job and I'm glad it worked out for you.
