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The fastest plane I ever flew!

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The fastest plane I ever flew!

Post  RknRusty on Sun Dec 09, 2012 7:14 pm

And I ain't kidding. Lets review:
Plane: ReFried Bean
Total AUW: 6.38oz
Wing loading: 7.4oz/sq ft
Engine: Big Mig .061, 5.5x3 MA prop
Launching RPM: 22,300
Lines: 40'

After last weeks maiden flight, which was fairly ordinary at about the speed I'm used to, probably 60mph, I changed a few things to perk it up. Removing the muffler and swapping to a lighter wheel had it balancing perfectly level with no added weight anywhere on the airframe. Perfect, I nailed that part of the rebuild. I had test run the engine with a 1/2" shorter prop, down from a 6x3 and it ran almost 3500 rpm faster on the ground with it's newly sealed venturi, free of air leaks.

Today, I warmed up with two flights of the Baby Streak and then put the Re-Bean on the lines. I warmed up the engine for about a half minute and set the needle where it just rolls off rich, maybe a bit more. It took off from the stooge and hit flying speed instantly, tight and level, so on the second lap I pulled a loop and after it was level the engine died. It made an exquisite glide and softly landed a lap later rolling on the grass. I ran over and pinched off the fuel feed and reset.

I added some more fuel, confident that all was trimmed and balanced and lit her off again, slightly leaner. Baby, that's all she wanted. I remember looking at the profile as she screamed around the circle and thinking, what a perfectly strange looking little beast. These were the fastest laps I have ever turned with a plane, and I'm talking Way Way faster. It takes my Streak 3 seconds to turn a lap and this felt twice as fast. You don't have to believe that, but I do. I started my routine of loops, inside and outside, inverted with outside loops and figure 8s, and now wingovers. I've been practicing those on my other plane and getting pretty neat at it, and this plane didn't disappoint. Even while pausing to do stunts I was still turning fast enough to get dizzy, and I stumbled badly, my hat falling off as I followed the plane around, so I started extending the number of consecutive loops and 8s, and that preserved my control pretty well.

I got to thinking, maybe 45' or 50' of line would be better for this speed demon. I was not overwhelmed, but still beyond my comfort zone for fun flying. Thinking the end of the run must be coming up soon, I was still mixing up stunts and turning fast circles. I decided to elongate my 8s to a half a lap and got a little high and behind me on the left. No problem, I had been practicing flying blind with fair success and no crashes. I fed it some up to bring it back and spun to my left to get a visual on it. The last thing I saw was the sun, and I heard it hit the ground. For the life of me, I don't know how I flew it into the ground. I thought I knew where it was and fed the appropriate input, but there she lay, the whole plane minus the outboard wing which was 10 feet away and had broken off cleanly between rib numbers 1 and 2 at the edge of the sheeting extension I had added.

Both tail booms, the stab and the nose, everything I had rebuilt were fully intact, like nothing had happened. Only the Monokote is ripped up on the underside of the inboard wing. The controls still work fine. The engine was dirty but neither the LG nor the needle was even bent. The bladder was still hooked up and had a buckshot sized ball of fuel still in it. If I had managed to keep it in the air just a few more seconds, I could have parked her until I rigged up a longer set of lines.


I am very very disappointed. Maybe the lesson is: don't spend two months meticulously rebuilding a plane that has taken so much punishment and full speed vertical crashes in it's first life. Or maybe any plane would have come apart like this, hitting the ground at... possibly over 100 mph. Maybe a Norvel .061 on a 4.4 ounce airframe is a bad idea. Shoulda, coulda, woulda.

Maybe some fiberglass and epoxy could hold it back together, but I'm not expecting it or getting my hopes up. I'm sure the wing LE has plenty of invisible stress fractures that may well have been pre-existing.
I thought I was through building for a while.
Phooey!

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Re: The fastest plane I ever flew!

Post  Ken Cook on Sun Dec 09, 2012 7:46 pm

Rusty, I share your pain. I've been there. I can only say, to use a smaller prop. Let the rpm's scream away. Even with a 5" prop you still may be questionable with the power of the .061. These engines are powerful. We fly on 42' lines but we've had matches on 35' lines which is insanely crazy. I certainly wouldn't go crazy with the epoxy and glass. Clipping your prop tips and leaving the tips squared off really decreases the efficiency of the prop. I've run props like the Cox rubber ducky at 4 1/4 on my Big Mig and less. My AME .061 is turning a rubber ducky with a 3 7/8" prop. I run the AME and Shawn has the Big Mig. In order for both of our planes to fly at the same speeds, the AME uses the smaller while the Big Mig uses the larger. Seeing that prop size controls the speed of the plane, even though you trimmed the prop it was still quite large. I certainly wouldn't try and regulate the speed of the plane using the needle as it generally doesn't work. Let the engine run up. Certainly reducing the pitch may also help like the APC 5.5 x 2. I never had success with the APC 6x2. Others have, it just beat air for me. The 5.5 x 2 and the 6x2 have different prop shapes and the 5.5 x 2 worked well for me on suction but I never tried it on bladder. I also like the APC 4.6 x 3 but I trim a additional 1/8" off the tips. The APC's have airfoils that work well and they don't flex like the rubber ducky props so it all becomes experimental as this could really make the plane either work well or make it even go faster. What I don't like is that you can generally buy two of the 5.5 x 2's to the price of one of the 4.6 x 3's. These break extremely easy even on a graceful landing. I hope you get the Bean back together. Good luck, Ken
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Re: The fastest plane I ever flew!

Post  RknRusty on Sun Dec 09, 2012 8:08 pm

Thanks for your sympathy, Ken. I'm kind of embarrassed, I thought I was better than that. I think it's just going to be a pretty hangar decoration and never fly again. It was probably weakened in its first life too much to trust. I sure wish I'd had a video running for that flight. It was a wonderful run, up until the end. It was a hell of a lot slower last week with the 6" prop, but clearly unhappy.

I have my newly acquired Baby Streak to try the Norvel on again when I finish fixing the control throws. So maybe a Cox or MA 5" prop will fly slower than a 5.5", just higher RPMs?

Today on the Streak, I went from a 5.5x3 to a 5.25x3 and it quit slowing so much in the loops, but the plane felt a little slower. But it would stand on the end of the lines straight overhead and do tight circles. I tried an 8 straight overhead and either the breeze knocked it down or I lost it, but it didn't crash and I finished out the run. My wingovers are getting pretty. Sometimes I pull up too much and climb out instead of leveling off, but other times I nail it perfectly. I guess in this sport, you never get past crashing badly once in a while... even on a calm day.

I was given another Big Mig .061 today, so now I have 3. Plus a bunch of NIP glow plugs and other parts. And a fistfull of new Tornado props. Some really rubbery 5.25x4s too. Those might fly well on my Tee Dee Streak.

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Re: The fastest plane I ever flew!

Post  John Goddard on Sun Dec 09, 2012 9:00 pm

I went to see Skyfall the other week.
I sat there looking at JB with his new
Goatee thinking that bloke usually has
A plane on a string on utube....

Don't worry about shoulda Rusty, remember
You are the Rustmeister, get the cyano out
And show that so and so who's BOSS.

Very Happy
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Re: The fastest plane I ever flew!

Post  RknRusty on Sun Dec 09, 2012 9:16 pm

John Goddard wrote:...
You are the Rustmeister, get the cyano out
And show that so and so who's BOSS.

Very Happy
Thanks for the encouragement, John. You're right, that is my workshop mantra. I don't take no crap offa no machine. I used to make a living on that attitude. I've still got it. You just reminded me.

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Re: The fastest plane I ever flew!

Post  RknRusty on Sun Dec 09, 2012 9:18 pm

John Goddard wrote:I went to see Skyfall the other week.
I sat there looking at JB with his new
Goatee thinking that bloke usually has
A plane on a string on utube...
Haha I just got that. lol!

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Re: The fastest plane I ever flew!

Post  Cribbs74 on Sun Dec 09, 2012 9:26 pm

Man Rusty,

That does suck. Maybe you should set it aside for a couple days and come back to it when you are less upset. As you very well know Epoxy and glass tape is some crazy strong stuff. Usually when I crash after fixing a plane it breaks behind or before my epoxy repair.

No plane should ever be a hangar queen Wink

Besides, I'd be interested in hearing what prop you settle on.

Ron



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Re: The fastest plane I ever flew!

Post  pkrankow on Sun Dec 09, 2012 9:35 pm

Ouch.

Covering the stump with packing tape (or not) and continuing to fly would have been considered in my youth.

Phil
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Re: The fastest plane I ever flew!

Post  RknRusty on Sun Dec 09, 2012 10:28 pm

I was just looking at the thing a little closer. Wondering if the wing might have folded in flight. More crash analysis later. Maybe I'm only wishing it was the plane and not me.
lol!

I keep learning new things about props. I'm glad we have real aerodynamic experts around here.

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Re: The fastest plane I ever flew!

Post  Surfer_kris on Mon Dec 10, 2012 12:18 am

Sorry for the plane, but most things are easily repaired, it is only wood. Give it a day or two and then you'll know what to do.
Welcome to the Norvel club, it gives a new dimension to 1/2A flying.
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Re: The fastest plane I ever flew!

Post  fredvon4 on Mon Dec 10, 2012 7:13 am

The R-Bean will fly again, I bet....

Rusty.... I would consider a 6 to 8 inch tube of carbon fiber internal connector for the LE spar. Drill a slightly larger dia hole in both sides with a long bit.

For foam and balsa you can make your own long drill bit with brass or copper tube by filing crude "teeth" on one end. Leave the tube bit hollow and if necesary (wont go in after two or three inches) remove and punch out the balsa core with a thiner dia tube and continue the hole plunge drilling
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Re: The fastest plane I ever flew!

Post  daddyo on Mon Dec 10, 2012 10:03 am

Sorry to hear about your plane. But you got me thinking about line length, I've been trying to combat with Norvel 061's with 35% nitro with Lil Satan look-alikes on 25' lines, maybe that's why we're having so much difficulty??
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Re: The fastest plane I ever flew!

Post  RknRusty on Mon Dec 10, 2012 11:09 am

They can be too much to handle on short lines. I had to go up from 35 to 40' when I built the baby Flite Streak just to make it manageable. That extra 5' made a world of difference. I wouldn't want to fly anything faster than a toy plane with a Babe Bee on less than 35'.

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Re: The fastest plane I ever flew!

Post  RknRusty on Mon Dec 10, 2012 11:11 am

Fred, since nothing but the wing has any damage, I think I'll liberate the old one from the wreckage and make a new one. Probably with a little longer span too.

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Re: The fastest plane I ever flew!

Post  andrew on Mon Dec 10, 2012 11:24 am

Surfer_kris wrote:
Welcome to the Norvel club, it gives a new dimension to 1/2A flying.

Tough luck, but all our stuff has an expiration date --- it's just not known when it will happen. You'll be back up and running in no time.

At the chance of being tarred and feathered by a COX group, the NORVEL really is an exceptional engine for a reasonable amount of money. It's a little unfair to compare the .061 to the .049 since it does represent a 25% increase in displacement. But, nonetheless, swapping a NORVEL onto a plane can really make it step up, especially running an AME on 35% with crankcase pressure.

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Re: The fastest plane I ever flew!

Post  fredvon4 on Mon Dec 10, 2012 3:18 pm

Rusty as you know (tis a cox forum) I am interested in relearning C/L and currently living vicariously through you, cribs, and ken as well as other here

That said, this plane, and your Norvel Big Mig caused me to get a Norvel, some old skool kits, and even copy your stooge....I was really grinning at your invite and flying on Fort Jackson RC club, as I have many hours (while temp duty there) watching the guys fly just a few short years ago.

I think, just for grins, you might seriously consider retrieving two ribs, making a ply template, researching internet, and resurecting the Refried Bean in foam wing. I would be interested in reading ken's and others advice to you as you experiment with hot wire and solid core foam.

Decades ago I was lawn darting my 50 hours plus balsa wings into scrap and learned how to make a crude hot wire cutter and cut very strong and cheap wing cores for play and competition. IIRC the Bow, nichrome wire, battery resister power, and large blocks of foam allowed me to do circle birds for under $15 each including glue, covering, and scrap balsa

any way...just a out loud thought....you seem to love to experiment and learn new dynamics to this hobby
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Re: The fastest plane I ever flew!

Post  daddyo on Mon Dec 10, 2012 3:33 pm

RknRusty wrote:I was just looking at the thing a little closer. Wondering if the wing might have folded in flight. More crash analysis later
So who's going to invent the hobbiest Black Box? Maybe you need to keep the film rolling at all times. If it did fold, well you still can't really blame anyone else unfortunately...
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Re: The fastest plane I ever flew!

Post  dckrsn on Mon Dec 10, 2012 3:55 pm

Sorry about the Bean Rusty. I've been following the thread from
day one, and didn't really know what to say. All bad bits aside,
I was thrilled with your description of the speeds you hit.
Hats off for reaching a new level. Hand Shake
Bob
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