New Piet owner near St. Paul

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jeffreyuh60
Posts: 3
Joined: Sun Sep 06, 2020 8:21 pm
Location: New Richmond, WI

New Piet owner near St. Paul

Post by jeffreyuh60 »

Greetings All,

I recently acquired a GN-1 aircraft and would like a little help looking her over and developing a get back into the sky list. She is in my hangar at KRNH, sans wings for the moment. She is powered by what I believe is a '67 (logbook says '66, but the serial number indicates a '67) Corvair engine, 110 hp, with a Tillotson model X carburetor. The engine has not been converted, as far as I can tell. She has a H. Rehm 66 x 38 propeller, but it is not airworthy due to delamination and several cracks. Additionally, she sports J-3 type landing gear, but I am unsure which type, and what I believe to be a 12 gallon J-3 main fuel tank.

This is one of Bob Ward's birds (N174LS) that sat at the Log Cabin Airport (WS69) for many years. I doubt he ever flew it after he bought if from the builder, Clarence "Sam" Samuels, of Watertown, WI. Any further background information would be very helpful.

The good news- she has a previous FAA registration (circa 1992), so I will be applying for a new Aircraft Registration Certificate, along with a new tail number. The previous N number belongs to another aircraft. I have the airframe logbook and have received the aircraft records from the FAA. The engine and propeller are original. The airframe and wings appear to be of good craftsmanship and are in decent structural shape.

A few obstacles to overcome- there are no engine or propeller logs, so both are MCU, pending inspection, overhaul, or replacement. Also missing is the build log, POH, and equipment list, but I will create the latter two. Am I correct that I do not need the build log since she has previously been registered?

I believe with a little work and some experienced assistance, I can get her back in the air. I appreciate any assistance and advice from the group.

Thank you.

Jeffrey Turner
N39BF reserved
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Jeffrey Turner
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taildrags
Posts: 388
Joined: Tue Mar 07, 2017 10:39 pm

Re: New Piet owner near St. Paul

Post by taildrags »

Jeffrey; if I may offer one bit of advice, here's something that you can do that will cost you nothing, requires changing or removing *nothing* from what you have there, and will provide you with a very valuable amount of information about your airplane before you spend any time or money modifying any of it. The airplane does not need to be airworthy or registered, and the engine does not need to be operational. What's that something? Spend a nice Saturday measuring up your airplane and performing a careful weight & balance of it.

All you'll need is a level and clean surface to work off of, indoors or at least under cover so that there is no wind to move the airplane or disturb you while you work The only tools needed are a pencil, notepad, measuring tape, bubble or angle indicator, roll of painter's tape or other tape to mark locations on the floor you're working off of, a plumb bob (which you can make using a pyramid fishing weight and some good braided twine), and a set of three scales. If you don't have, or can't locate, a set of three accurate scales of the same make, model, and style, then you can still run all the measurements and run a trial W&B using bathroom scales but eventually you'll need a matched set of accurate scales if you want to do it right. If you have an EAA Chapter in your area, inquire about a set of race car scales, which many EAA chapters have and will loan or rent out. As I say, don't let this stop you from running a trial W&B with just plain bathroom scales, preferably matched but that's not a big deal either. The ones for the mains are going to be measuring weights in the 250-300 lb range, so if you weigh anywhere near that amount, you can just stand on each of your scales and adjust them before you get started so they all read the same and you'll be close.

Set up the airplane in the straight & level attitude with the wheels chocked so it won't move. Set your bubble level or angle indicator on one of the top longerons and zero it up by adjusting the tailwheel stand and you're ready to take your measurements. You'll want to do all the measuring before you put the airplane on the scales, but I suppose you could just do one setup by putting it on the scales before you measure. Measure everything you can think of, but if you need a list of useful measurements to take while you've got everything set up, I'd be happy to send you one. I also have an Excel spreadsheet to run W&B, but you'll have to change the values in it to suit your airplane before using it.

Most of the measurements can be taken by one person, but many are a lot easier to take with two people doing it. If you don't have a Smartlevel with digital readout but you do have an angle finder app on your smartphone, you can use your phone with that app to measure a couple of things like wing incidence and washout, wing cabane angles, the deck angle with the airplane sitting in the 3-point attitude, pilot's seat back angle, downthrust built into the engine mount, and various other things here and there as you think of them. Don't be in a hurry; make a day of it and don't take the airplane out of your setup position till you scratch your head and look at all your measurements, because as sure as the sun comes up tomorrow, after you get it off the stands and scales, you'll remember something you didn't measure and you'll need to set it back up again.

Make a sketch of the airplane (or copy a 3-view onto a good-sized clean sheet of paper like 11x17", on a clipboard) and record your measurements on it as you go, being careful to mark clearly where each measurement was taken. Front face of the prop flange is one that sometimes gets confusing, but just remember that even if you change props and their thicknesses are different, the front face of the prop flange won't have moved and it's a good reference to have. Main gear axle position relative to the wing leading edge in the level configuration is important. The outside to outside of the tires, or at least to the center of tread on each, will be useful if you ever have to trailer the airplane on a flatbed or fit it into an enclosed trailer with the wings off. I found that mine just barely squeaked onto a hay hauler trailer without having to fit some outriggers to the flatbed, just by knowing what the outside width of my main gear was and checking the trailer before I borrowed it.

I think you'll find that the day you spend taking the measurements and getting a trial W&B will be some of the most useful and enjoyable time that you will spend with your new airplane, it will tell you a lot about how it may handle when you fly it, and it will provide guidance on what you might want to modify before you attempt to fly it. Additionally, there is such a deep base of knowledge about these airplanes after 90+ years of building and flying them that it's quite easy to spot anomalies among the airplanes by comparing your numbers to others that have been built and are flying successfully. Also, comparing your airplane's vital dimensions to those shown in the plans may alert you to something that may not be right on your airplane, or that the builder may have modified for some reason. Without the builder's log that provides an explanation, you can at least investigate why a dimension on your airplane is different from what the plans show. All of this will get you much more familiar with your aircraft as you learn it, and that's a good thing.

Oscar Zuniga
Medford, OR
Air Camper NX41CC, A75 power
jeffreyuh60
Posts: 3
Joined: Sun Sep 06, 2020 8:21 pm
Location: New Richmond, WI

Re: New Piet owner near St. Paul

Post by jeffreyuh60 »

Oscar,

Thank you so much for your detailed advice. I have been conducting research in the subject of Pietenpol W&B and recently acquired the Pietenpol W& B Manual from William Wynne. I do have some concerns about the W&B of this aircraft based on three items; the struts are vertical, I suspect the aircraft has low time (possibly due to an out of CG issue), and I am not a little guy (6'0", 225#). This will present some challenges for me, but I agree with your sentiment- creating a baseline W&B is an excellent beginning.

v/r
Jeffrey Turner
N39BF reserved
Earl Brown
Posts: 33
Joined: Mon Nov 04, 2019 12:24 pm

Re: New Piet owner near St. Paul

Post by Earl Brown »

Hi Jeffrey

William also sells a maintenance and operations manual for the Corvair.
It's on the website- https://flycorvair.net/product/0300-mai ... es-manual/

He is definitely worth contacting about the engine.
His email and phone number are also on the website.

Earl
gcardinal
Posts: 11
Joined: Wed Feb 22, 2017 5:02 am

Re: New Piet owner near St. Paul

Post by gcardinal »

Jeffrey,

There is LOTS of Pietenpol activity in the Twin Cities.
We have some info on your Air Camper.

Call Greg Cardinal at 612 790-9827
or
Bob Poore at 612 893-0235
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taildrags
Posts: 388
Joined: Tue Mar 07, 2017 10:39 pm

Re: New Piet owner near St. Paul

Post by taildrags »

Jeffrey; note that if your GN-1 is built per plans, the cabane struts will be vertical because the wing cannot physically be moved aft on a GN-1. The attachments for the struts do not create "pivoting four-bar linkages" as they do on the Pietenpol.

And don't start worrying about W&B before you know how it actually shakes out ;o)

-Oscar
jeffreyuh60
Posts: 3
Joined: Sun Sep 06, 2020 8:21 pm
Location: New Richmond, WI

Re: New Piet owner near St. Paul

Post by jeffreyuh60 »

Thank you Greg and Oscar, I truly appreciate your help. I will make contact this weekend, hopefully. I need my hangar finished before I move in fully. I was wondering if there is a "tool crib" feature in the St. Paul area? Is that something that people do? For example, I have an engine stand and will soon have a wing rack open.

Thank you.
Jeffrey Turner
N39BF reserved
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