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Initial flight 2 Apr 2017

Posted: Mon Apr 03, 2017 2:38 pm
by Don Youngblood
My initial Tailwheel SOLO 2 Apr 2017, in my personal creation, N41YB. Long fuselage, 3 pc wing, 2-3/8 dihedral, Carlson alum struts, 4130 cabanes & diagonals, C-150 gear and brakes, MATCO tailwheel, Cont A-75-8 by Don's Dream Machines of Milner, GA, Sensenich Experimental 70 X 42, Turtleback raised to Inst Panel height, 24" width carried aft to pilot's seat back, plus other mods, EWT 667#. Can carry up to 198# pilot within 20" aft C.G. CFI had flown it twice before and pronounced it straight with no bad manners. Initial (accurate?) instrument readings at 3,500 MSL: 95 mph @ 2,450, stall 35, oil temp 150, oil press 40. All welding and fuel (13 gal wing & 2-1/4 gal header) by local professionals. I'm initially operating on grass, at LQK (Pickens County, SC). Thanks to EAA 249 and Pickens County Pilots Ass'n, Pat Weeden for this Builders Forum, Matt Dralle for MaTronics site, WestCoastPiets for photo archives, Oscar Zuniga for advice, engine & fin offset photos, and used eyebrow scoops, Peter Johnson in Australia for his build/photo archives and advice, Mike Cuy for his elevator trim photos, many others elsewhere who helped in this 6 yr build, and the 3 other PIET flyers in SC (Beck, Harper, and Fastnaught) for advice and parts. Finally thanks to John Leupp and the 3 other CFIs who put me in the Pilot's Seat. Don Youngblood, a.k.a. planes&bikes.

Re: Initial flight 2 Apr 2017

Posted: Mon Apr 03, 2017 6:32 pm
by vk3eka
Congratulations Don, thats a fine looking Pietenpol you have there!

Cheers

Peter

Re: Initial flight 2 Apr 2017

Posted: Mon Apr 03, 2017 9:54 pm
by taildrags
Don; I'll add my congratulations to those of the others who cheered you on, and it's great to have another Air Camper flying. I'm very interested in your performance stats since our airplanes weigh within about 30 lb of each other empty and both have recently-overhauled A75s. My prop is a 72x36 and yours is a 70x42, and the 95MPH at 2450 RPM that you've reported bears out the fact that mine has less pitch because the only way I can hit 95MPH is to point the nose down and hold on with the engine at redline till I have to cry 'Uncle' and ease up on it. At 2450 I'm probably only seeing 70-72MPH. I have not flown any time-to-climb runs since changing out the A65 and Hegy prop to the A75 and Culver prop, but I hope to get out and run some test cards pretty soon.

Re: Initial flight 2 Apr 2017

Posted: Tue Apr 04, 2017 9:37 am
by Pat Weeden
Nice job, Don!

Re: Initial flight 2 Apr 2017

Posted: Wed Apr 05, 2017 9:36 am
by Don Youngblood
The performance numbers should be considered preliminary, as I have personally flown it only once (2X prior by C.F.I. Test Pilot), and have not checked airspeed against GPS. 95 mph indicated felt uncomfortably fast, but engine builder recommends 2,450 rpm break-in, so I'll hang on and get GPS or other confirmation of accuracy. 70 X 42 prop was engine builder's advice, and I followed it based on his having built/flown a PIET. Short ground run, almost pattern altitude by end of 5,002' runway, and fast cruise seem to confirm good decision. I'll compare time-to-climb #s with you (Taildrags) when available.

Re: Initial flight 2 Apr 2017

Posted: Wed Apr 05, 2017 11:33 am
by Steve D
Yahoo! great job getting it up in the air.

Your numbers appear a little optimistic. But for the Pietenpol numbers are just for reference. the only really important ones are approach and stall speeds for safety and normal cruise with fuel burn for planning your trip to Oshkosh.

Blue Skies,
Steve D

Re: Initial flight 2 Apr 2017

Posted: Wed Apr 05, 2017 11:23 pm
by taildrags
Don;

I've gotten the same advice about recently-overhauled cylinders/pistons/rings... in order to seat them, the engine needs to get up to temperature and stay there, although not at a constant RPM (simply ground running it, for example). I was once lucky enough to get a ride in a Starduster Too that had a couple of overhauled jugs put on it and needed some break-in time. Climbing for the stars!

Re: Initial flight 2 Apr 2017

Posted: Wed Apr 05, 2017 11:39 pm
by taildrags
Don; by the way, there was an excellent climb test procedure published in the October 2000 issue of EAA Sport Aviation, by Ed Kolano, to develop an airplane's climb charts. It's a perfectly good procedure that will generate enough data points to establish a useful graph of climb performance at different airspeeds, like what you might fly in a Zenith or an RV, but the airspeed and altitude ranges of an Air Camper are so limited that it might prove difficult to hold a target airspeed through enough of an altitude block to get a good reading. That and the fact that you might doze off while waiting for the airplane to climb 1,000 feet through one altitude block, means that it might take a while to get enough data points to graph ;o) In my case, I would probably only fly between about 1500' and 4000' (five altitude blocks) in five airspeed ranges (50, 55, 60, 65, and 70 MPH) to gather test data... and even that limited range might not be feasible in my airplane without interminable waiting or possibly running low on fuel. That's 25 data points and if I use a rough average of 5 minutes to climb through each of the altitude blocks and maybe 10 minutes to get back down to starting altitude between runs, (clearing turns and all that), I'll be at minimum comfortable fuel and tailbone after 2+ hours of that. It will be fun and interesting, to be sure.

Re: Initial flight 2 Apr 2017

Posted: Thu Apr 20, 2017 1:09 pm
by Pat Weeden
Here's a video that Don's son posted on YouTube of the first flight. Pretty cool!

https://www.youtube.com/watch?v=jhFhqnJReCY