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Old Apr 04, 2003, 01:45 AM
Registered User
College Park, MD
Joined Sep 2002
4,714 Posts
Alfa Models P-47 Thunderbolt "Tarheel Hal" Maiden Flight

This morning I had a successful maiden flight of my Alfa P-47 I painted like "Tarheel Hal" I added retractable main gear and tail wheel. I also modified the rudder to work and created new servo and battery mounts. The RTF weight was a little heavy at 16.4 ounces. I only have a four channel radio so I have the landing gear lock in the down position.
The P-47 lifted off in about 20 feet and climbed swiftly at full throttle. I almost lost it because the elevator was too sensitive but gained control once I lightened up on the stick. It took alot of down trim because I had set the elevator neutral trim too high. I figured that since the model was heavy it would need some help.
I thought the closest airframe to the P-47 I had flown previously was the Flying Styro Crazy Sparrow. Well, I can tell you that the two models are vastly different. The P-47 is faster and more stable. I was able to fly comfortably on 1/2 throttle and rolls were performed easily. The stall characteristics are excellent. The model just mushes forward without dropping a wingtip. Stall speed seems to be around 10-15 MPH.
The landing was good but I tipped over before coming to a stop. The retractable tail wheel had snapped off and was nowhere to be found. I've already made a replacement tail skid. I prefer tail skids over tailwheels because I fly mostly from a baseball diamond. Tail skids also slow the model down faster after landing.
I flew the model for about five minutes at half throttle. The battery had only discharged 366 mAH so I figure around 6 minutes of acrobatics or 10 minutes of crusing will be possible.

Specs:
16.4 ounce AUW
Speed 300 MPJet 5-1 BB Gearbox
9x6 APC SLowfly prop
8 cell 800 mAH 5/4AAA NiMH battery
Hitec Feather RX (maybe Hitec 555
GP C-10 ESC
Pico+ servo for Ailerons
PicoBB servos for Elevator/Rudder
NaroHPBB serov for retracts

--Mark
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Old Apr 04, 2003, 02:53 AM
Look mom, I can...crash.
IMCingYou's Avatar
Oregon
Joined Mar 2003
306 Posts
Thats a beautiful bird.

Congrats on an almost glueless maiden flight. (pesky little tail wheels) Its always good to hear of a first flight in a new aircraft that doesnt require a trip to the toolbox for some more CA.

what were the winds like? I ask because today I encountered an hour of NO wind. For me, here in the Pacific Northwest, thats odd.
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Old Apr 04, 2003, 08:59 AM
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College Park, MD
Joined Sep 2002
4,714 Posts
Thanks for the compliment. I'm glad I didn't require any CA the first time out...

But I wasn't so lucky this morning. There was a slight breeze blowing off and on but I didn't think I'd have any problems. WRONG!

I took off and immediately noticed that something was wrong. The model was climbing well but the aileron control felt really mushy. I was having a real hard time keeping it pointed straight. The trim needed several clicks of left. Strange since I hadn't changed anything since the first flight. It was also floating like a glider. I was at 200 feet really quick and the winds were literally carrying the model away. I decided to bring it down and it was a difficult to do so. I had chopped the throttle to about 1/4 and it was still hanging up there. I pointed the nose down and spiralled around the field bringing it down slowy. The wind had picked up a bit by the time I was on final approach. The wind knocked the right wind down at 1 foot and it nosed into the dirt. I tried to compensate but the aileron control was too weak.

The cowl cracked at the bottom and the right wing got a hairline crack at the root. Other than that it seems OK. But what had caused the problem? I looked at the underside of the wing and the left aileron pushrod had separated from the control horn. Doh! I remember starting that step and trying to use the little DuBro pushrod keepers. The wouldn't fit because the pushrod wire was too small. There was enough tension (I thought) to keep the pushrods on. NOT! I'll put the little tubing keepers on the ends and be done with it.

We live and we learn.
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Old Apr 04, 2003, 09:19 AM
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Aldur's Avatar
Seminole, FL
Joined Nov 2002
414 Posts
Wow! What a nice job. Congrats on the maiden, keep up the good work.

Beautiful!

Thanks 4 sharing,
Scott
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Old Apr 04, 2003, 01:49 PM
Look mom, I can...crash.
IMCingYou's Avatar
Oregon
Joined Mar 2003
306 Posts
Oooowww I hope my no CA comment didnt jinx your next flight. Things obviously could have been worse. Thanks for keeping us in the proverbial loop. And once again thats a beautiful plane.
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Old Apr 05, 2003, 12:30 PM
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Deltawing's Avatar
Woodinville
Joined Dec 2002
50 Posts
I have followed the Tarheel threads all along and just want to say how much I admire your work on this plane.

I, too, have an Alfa p-47 but the weather has postponed my first real maiden flight - and that's probably a good thing because I, too, have figured I could get by without capping of those control rods.

Thanks to you, I can now avoid a potentially much worse disaster than you endured.

Thanks for sharing, as they say :-)

And I look forward to the further aerial exploits of Tarheel Hal.


-Deltawing
(Pilot-owner of an indestructible Beaver, a broken forever mustang, and a virgin P-47)
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Old Apr 05, 2003, 02:34 PM
My cat up close
bipeflyer's Avatar
England
Joined Feb 2001
4,021 Posts
Lovely model.Added that to my must have list....
Can you tell me what brand of retracts did you use?
Congrats on the fine paint job!

Matt
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Old Apr 05, 2003, 03:53 PM
jah
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North Georgia
Joined Nov 2001
1,851 Posts
Great looking P-47! Awesome work.
Jerry
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Old Apr 07, 2003, 10:17 AM
Registered User
College Park, MD
Joined Sep 2002
4,714 Posts
I repaired the cowl and wing without much difficulty. I noticed that the right GWS Pico retract had a hairline crack in the housing so I removed both. I made a pair of fixed landing gear that screw into the existing retract mounts.

I had another couple of flights yesterday in winds of up to 20 MPH. Really tricky landing but up high it performed really well. After flying this model in dead calm, the winds made it feel like a slowflyer again. The controls were just not that responsive.

The last flight ended with a hard landing. It hit with both wheels squarely on the ground and rolled to a stop. My dad called it a "Carrier Landing" I didn't think it was too bad but I turned the model over and noticed that the right wing had cracked along the root (again) This time it was the full length of the wing. The repair will be easy. I'll just use odorless CA along the crack.

But why was the wing separating from the fuselage in this manner? I thought the wing spar would be taking up the stress. I looked close at the point there the wing spars joined and found that the spars aren't joined but just butted together! Since the model wasn't designed to have landing gear they probably figured that a spar joiner wasn't necessary. Also, I probably exacerbated the situation by cutting the opening for the landing gear wheels. I'll put a lite plywood joiner along the front of the spar and see if that fixes the problem.
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