Al's B-17 'Dumbo' Build

badbill wrote:That's a Dare Designs B-17 kit intended for 4x Speed 400 brushed motors. There is some awesome build threads on RCG, with retracts and everything.

Thanks Bill. Al probably told me (I think he refers to the designer by name), but I was entering my 'afternoon mental fog', and it didn't stick...

Pat Tritle designed it.

http://www.rcgroups.com/forums/showthread.php?t=1132380

http://www.rcgroups.com/forums/showthread.php?t=1840407&highlight=dare+b+17+build

Beautiful models! Thanks for sharing the photos Kim!

Thanks guys!

Figure that, in order to keep track, I'll just make this the Official Al's Airplanes Thread.

Speaking of which, I headed down there yesterday, in spite of the winds that didn't seem to be backing off in the evening.

The Dumbo's wings are now joined, and some cockpit area work has established that B-17 'scowl'.





Along with this, we ended up having a fantastic day with some air-to-air videoing, and the successful flight of Al's massive C-123 'Provider'.  He's sort of tagged me as an occasional test pilot, which is both an honor and fairly terrifying at the same time.

Our camera operator wasn't familiar with my Sony camera, and so the footage was pretty shaky, but I was able to capture some reasonable frames.

Waiting for the wind to back down a bit.  Al and his scratch-built C-123.



Walking the Provider to it's takeoff.




Al works in the C-123's cavernous fuselage.





And, we're off...











Al's pretty happy to have the Provider back on it's picnic table, while friend Brian looks a little less impressed.



As I'd hoped, the Fairchild blasted from Al's runway like it had JATO rockets strapped to it's backside.  It flew like a chubby sailplane under power (a little over half being plenty), but with a rapid deceleration when the motors were backed down.  Other than some trim issues (used a lot of right-trim), the cargo plane was real friendly right from the start, though I had to remind myself to take a breath once in a while.

So, the Provider is now part of Al's flight line.

As if this wasn't a big enough deal already, we also continued our decade-long attempts at videoing Al's creations air-to-air.  We had the most success ever (funny how things can get easier if you have two planes with fairly matched performance.

I scotch-taped my new GoPro to Mud Dabber's right wing-tip (to avoid the O.S. castor slinger on it's nose), and since both cameras weigh the same, taped the other GoPro to it's opposite wingtip, pointed backwards.  Caught the usual kibitzing from the locals about all the scotch tape I use, but pressed forward anyway.

Al's selection as 'Subject Airplane' was his Turkish-marked Vultee (can't remember the model number), that can really scoot.  The beautiful plane has retracts, which are cool, but the thing blasts through the air whether the wheels are up or down.  Right now, I've just got video captures, but will have a movie put together shortly.

We don't always choreograph our flights real well, but managed to mostly keep some good space between us.  I DID manage to be passing down the runway as Al launched on the second session, and blasted past Mud Dabber's tail like a P-51 taunting a Piper Cub.  A thrill for the locals, and no paint swapped, so it's all good.

I was pretty conservative on the spacing this time out, but figure to close it up some on our next run.

Al's beautiful Vultee





The Vultee's shadow crosses the runway as it comes tearing from beneath the T shelter, just as Mud Dabber turns inbound



The owner of the shadow



Our imitation of WWII gun camera film



On the first flight, Al's esc cut the power, and he put the Vultee down in the grass. No damage though.





He put it on the runway on the next flight.





Once again a novel...durn digital cameras are gonna be the death of me !!!

Wonderful coverage of your day's modeling events as usual! Just wondering; does Al's C123 use the same props on both motors? I'm wondering if it's possible to reverse the rotation on one of his motors and use a L/H prop (if available in that size)? Something he may want to explore with the B-17 too.. I'm thinking that he might need even more right-trim on that model.. but who knows. That's comparing a low-wing multi with a high-wing multi. Is one more susceptible to P-factor than the other?

roddie wrote:Wonderful coverage of your day's modeling events as usual! Just wondering; does Al's C123 use the same props on both motors? I'm wondering if it's possible to reverse the rotation on one of his motors and use a L/H prop (if available in that size)? Something he may want to explore with the B-17 too.. I'm thinking that he might need even more right-trim on that model.. but who knows. That's comparing a low-wing multi with a high-wing multi. Is one more susceptible to P-factor than the other?

Thanks Roddie!

Yeah the props were counter rotating, though Al did make a joke that he should have made them same direction, to 'give me a challenge'. The left-turn was in roll only--the rudder stayed almost centered---and persisted even in the glide, so he may have a bit of a warp out across that big wing.

We're gonna go again, with key fob cameras attached.

He's no stranger to multiple engines, having built a Lancaster, Wellington, and a four engined Antonov of some type that dropped little balsa fighters (the guy gets some ideas!).

Don't know about the p-factor with this one, being a shoulder wing, but figure it might be more noticeable in a low winger or with more engines.

Here's some video crunched from footage last Sunday. This is all of Mud Dabber chasing Al's Vultee fighter.



https://www.youtube.com/watch?v=Ti-HsdTstBs

SUPER COOL MAN!!!!!!!!!! I especially loved the sound of your engine @2:53... a clip where you'd throttled down. My subwoofer throbbed.. and I think stuff started rattling in my workshop! Seems like a lot less wind-noise in these clips.

roddie wrote:SUPER COOL MAN!!!!!!!!!! I especially loved the sound of your engine @2:53... a clip where you'd throttled down. My subwoofer throbbed.. and I think stuff started rattling in my workshop! Seems like a lot less wind-noise in these clips.

Thanks Roddie,

I think as much by accident as anything, the mics may have gotten scotch-taped over ! Good to hear that my ancient O.S. .35 can still put out some bass !!!!

Thanks for the flight report, Kim. It was well worth the time I spent reading and looking at the pics and vid. My compliments to anyone who can successfully build such a marvelous airframe as complex and delicate as that.
Rusty