EAA Chapter 25

A Community of Aviation Enthusiasts in the Twin Cities

Joel Fuller’s Waiex Flies for First Time

Filed under: Member Projects — joncumpton at 12:08 am on Tuesday, February 6, 2007

IMG_0364.JPGChapter 25 has another member with an airplane he built now flying. Joel Fuller reports, ” I made my first flight in Waiex SN 14 on January 13. The engine I selected is the Aerovee. I received my airworthiness certificate on December 9th, and had just been waiting for the holiday craziness to be over and the weather to cooperate.

I took off from Airlake at about 1:30PM. There was no wind and the temperature was about 9 degrees F. I basically just made one circuit around the pattern and landed. I was seeing some high cylinder head temps on my rear cylinders, so I decided to make it a short flight.

I have had a dream of building and flying my own plane since I was a kid, and I have finally accomplished it (yay!). The flight itself was totally uneventful, which is what I was counting on, but that didn’t mean the adrenaline wasn’t flowing pretty hard anyway. Now the flight almost seems like a blur.

The plane handles great. It has a nice balance between responsiveness and stability. The only other taildragger I have flown is a Cub, and all I can say is that the Waiex is way way easier to land and taxi (and start, and take off, etc.). Everyone told me this would be the case, and they were right. I don’t think I really looked at my flight instruments during the whole flight, I just did everything by feel.”

For anyone that is interested, Joel’s builder’s log website is here: www.mykitlog.com/joelfuller

Ken Beene’s RV-4 Flies For The First Time

Filed under: Member Projects — joncumpton at 7:33 pm on Sunday, December 17, 2006

KenBeeneRV4One.JPGThis last week saw the first flight of Ken’s RV-4 at Airlake. This is Ken’s second RV project — he previously built an RV-6A. Ken reports that the new airplane took 1900 hours to construct. Power comes from an O-360-C1G Engine with a Hartzell Blended Airfoil Prop. Empty weight is 1025 lbs, and the paint scheme is from an F-4-F Wildcat from Fighting Six in 1941. You can see construction photos at http://www.mninter.net/~kbeene/

Craig Nelson Nears Completion of Kitfox

Filed under: Member Projects — joncumpton at 10:10 pm on Monday, May 29, 2006

build009.jpgChapter 25 Secretary Craig Nelson has been working on his Kitfox for some time, and is getting close to completion. Craig reports, “The Kitfox has emerged from my basement workshop not to return. While it was in my basement I had the fuselage on a fabricated wood landing gear. I could not install the actual spring gear in the basement because it was too wide to get out of the double doors that I installed before starting the project. This past Saturday, my brother Mark came over and we successfully rolled the plane out the doors and into postion under my deck which we then used to hoist the plane up and put the gear on. The plane is now in the garage where I will continue final assembly in preparation for moving it to Winsted Airport.” We plan a visit to see Craig’s airplane in the near future.

Kitfox Update

Filed under: Member Projects — admin at 4:55 am on Monday, July 11, 2005

by Craig Nelson

from On Final July 2005Well, it’s past time for what is turning out to be my yearly update on my Kitfox Series 6/7 project. I continue to fit building time into a busy family (4 kids now) and work life. Progress has been slow but steady. As the weather warmed up in the spring of ’04 I got back into fabric related activities. Up went the spray booth in the garage and there it stayed through the summer and fall. The first task at hand was to finish spraying the wings. They had been storedfor the winter with two coats of silver on them. After sanding, I sprayed what should have been the final coat of silver prior to applying the color coats, but alas, I found my spraying skills were a bit rusty. I applied the silver coat too heavy which resulted in an orange peel texture. Sooo…sand and spray again. This time I got it right. After one coat of white, the yellow top coats (2) followed with a blue accent wrap on the leading edge which finished the job. Next came the tail feathers. These components had been covered but they still needed to have the tapes applied. This went well but I found applying the leading edge tape on the horizontal stabilizer to be quite a challenge. Getting the tape to stay down in the scalloped “valleys” between the ribs took quite a bit of trial and error as well as patience. But I got it and before long they were being sprayed with silver and the needed color coats. The fuselage then went back into the booth. It had been covered and sprayed through the base color coats the previous fall. Now it was time to add the blue accent striping down the side. After a lot of masking the stripes went on with great results. I enjoyed doing this accent work and seeing the results. At this point the only fabric work that remained was covering and painting the butt ribs. This required that some end plates be made out of aluminum sheet first. The builder’s instructions were not very clear for making these or how to cover the butt ribs in general. This posed a bit of a road block for awhile until I finally realized that I just had to get started and I would figure it out as I went. I have experienced this several times during the project. I like to be able to visualize how a particular process is going to go but sometimes it just isn’t meant to be that way. So, I have learned that I need to dive in and it will come together as I go. Anyway, with some careful work the butt ribs were done and again I’m happy with the results. The fuselage was then moved into the basement. By now it’s running into late fall and I still needed to paint some non-fabric items including the flaperons (aluminum skinned), their mounting brackets, and the spring landing gear. I wanted these to be painted with Polytone to match the fabric. Polytone does not adhere well to metal and fiberglass unless you spray it into a semi-wet coat of epoxy primer. This process dragged out because of the curing time (4 days) needed between coats when using epoxy primer. I stuck with it and got these items painted. In December I finally took the booth down for the winter. Sally and I were happy to be able to park in the garage again. In the colder weather months of winter I have been popping around working on different areas. I have installed the instrument panel and it’s associated instruments and avionics. Wiring of these components is nearly complete. I have fit the firewall and cowl bonnet to the fuselage. This spring I did some fiberglass lay-ups so that I could add NACA vents to the bonnet. These will be connected to eyeball vents in the instrument panel for a fresh air source in the cockpit. I’ve also modified the fiberglass wing tips to create a mounting pad for the nav/strobe lights. Earlier in the spring I finally received my Rotax 912S (100 HP) engine after about a 7 month wait. I started the engine installation process and found that my engine mount interfered with the back of the starter. It turns out between the time I got the engine mount and the engine, Rotax switched to a more powerful starter which made it longerÅ hence the interference. I sent the mount back to Skystar. They modified it to fit the new starter and had it re-powdercoated. Over Memorial Day weekend my son and I did a preliminary engine mounting to check fit. It sure is fun to see it hanging off the front of the fuselage. It’s starting to look like an airplane! This summer I will continue with the firewall forward installation, the final wiring details, and the mounting of the windscreen. Late in the summer I expect to be back in the paint booth painting the cowlings and doors. Well, that’s about it for this update. I have kind of given up forecasting a completion date but it’s very possible that my next update a year from now will find me with a finished aircraft. Now that’s a n exciting thought!

Pietenpol – First Flight

Filed under: Member Projects — admin at 10:59 pm on Saturday, June 11, 2005

by Christian Bobka

from On Final June 2005

Pietenpol - First Flight

Greg tends to underestimate the situation…

The first flight report of the Pietenpol is as follows:

2:40 was flown in five flights this morning and afternoon. Wind was 1/2 to full quartering right headwind at a steady 10 kts. Field conditions were dry grass. Location was Stanton Field, near Northfield, Minnesota. The ship has spoked motorcycle wheels and tyres rolling on bronze bushings with no brakes and a tail skid. A straight axle and wrapped bungies provided suspension. The first flight was 45 minutes, second flight was about 20 minutes, third flight was about 25 minutes, fourth flight was 25 minutes and the fifth flight was 45 minutes.

A few years ago I wrote a long dissertation on how to select the proper axle location with the 1929 style wooden gear legs installed on the long “Corvair” fuselage. I was right on the money in the analysis because at the aft CG loading that we had, the ship would perform flawlessly on the grass. Traveling 90 degrees to the 10 knot wind, I could turn into the wind by stick aft, windward rudder, and a burst of power and I could turn away from the wind by stick forward, lee rudder, and a burst of power. I was comfortable taxiing next to buildings and other aircraft with very little practice.

I weigh 220 lbs and Greg computed that we needed 100 lbs of ballast in the forward bag compartment (aft of firewall above passenger’s feet) to get loaded CG at .5″ forward of arbitrary aft CG limit (greg will have to give you the datum and the CG range, etc.) The ship is powered by an A-65 freshly overhauled with a homemade wood prop that was made using a duplicating machine copying an old Sensenich W72C42 blade from about 50 years ago.

The motor mount as originally made had TONS of down thrust and TONS of right thrust welded into it: like 1″ in each direction over the length of the crank. The angle would be arctan(1/24) . This looked so far out that spools were fabricated and used to shim the motor back until it had “a little” right thrust and “a little” down thrust.

On takeoff, a pronounced and uncomfortable tendency to turn left was observed which required a constant input of 1/2 right rudder at cruise settings and 3/4 right rudder at full power and climb speed. To let up on the rudder would invite a rapid yaw-induced roll to the left. This kept me making almost all the turns into the rudder (to the right for those of you in Rio Linda).

The aircraft is equipped with the highly calibrated Johnson wind vane type of airspeed indicator and it showed about 35-40 mph in the climb and about 55-60 flat out. The engine rpm in a moderate climb was 2100 indicated and the flat out rpm in level flight was 2220 rpm. The tach has not been calibrated. The rpms sounded right for 2150 or so in cruise and 2300 rpm (the correct number we want) level flat out. The left turning tendency is mitigated when power is brought back to idle. This fact identifies the problem to be a deficiency of right thrust at the motor mount and/or left offset of the vertical stabilizer. The aircraft flew well in the 1900 rpm range. I did not feel that much was gained by running the power up above 2100 rpm.

Anyway, Greg and Dale’s initial fix for this vicious left turning tendency will be first to offset the vertical stabilizer to the left to the maximum degree we can move it which is about 5/8″ at the leading edge of the vertical stab. This fix will be instituted prior to the next flight. Then the spool spacer on the motor mount will be adjusted to take out the rest of the left turning tendency that we find remaining. Those of you still building, plan to allow for adjustment at the vertical stabilizer leading edge, a little to the right and a whole lot to the left.

The A-65 equipped Piet is said to have increased vertical surface forward of the CG which offsets vertical surface aft of the CG. This is destabilizing in the vertical axis and appears to be present with the aircraft reluctant to return to straight ahead after a yaw is induced. I will investigate this characteristic after the aircraft is trimmed for hands and feet free flight. I would recommend that future Piet builders who plan to use an A-65 increase the size of their vertical stabilizer to help offset the increased vertical area forward of the CG with the A- 65 installations. A little extra way aft has quite an effect…

Another tendency the ship displayed was a severe nose dropping tendency. This required a tiring constant pull on the stick of more than 6 lbs or so. Letting go of the stick would hang me on the straps as the nose pitched over.

This could be attributed to engine downthrust or to aerodynamics and needed further investigation. I found that the pull on the stick was independent of thrust produced. It is an aerodynamic issue that needs to be cured by either lowering the leading edge of the horizontal stabilizer or raising its trailing edge. This is difficult to do in practice as the Vi Kapler rudder hinges are reluctant to move up or down the rudder spar. Again, current builders, allow for the ability to raise or lower the leading edge of the horizontal stab by using shims at the forward attach point only. You may also need a space to exist between the bottom of the vertical stabilizer and the centerline of the horizontal stab to allow for a slot where vertical positioning of the horizontal stab can be made. Just give some thought as to how you will allow the leading edge to be raised or lowered 1/2″ or maybe even more after the ship is assembled.

Knowing that we had 100 lbs of ballast in the forward bag compartment, we removed 40 lbs of it and that relieved maybe 1/4 of the 6 lb pull on the stick. Greg was concerned that would put the ship aft of the arbitrary CG aft limit. However, power-off stalls were performed both with 100 lbs and 60 lbs of ballast and in both cases the ship had no difficulty in lowering the nose to unstalled flight upon the slightest easing of aft stick pressure. When the stick was held full aft, gingerly use of the rudder could hold the ship in a falling leaf but you had to stay right on it with a good horizon. There was also a left wing heaviness that was mostly mitigated by shortening the left rear strut by 1-1/2 turns and lengthening the right rear strut by the same amount.

As test flights go, the ship was moderately difficult to fly as it needed continuous substantial input in all three axes, gobs of right rudder, a lot of aft stick, and a bit of right stick. I tried taking pictures but gave up after three because I could not take pictures and fly at the same time.

We will work through each item until the ship flies properly. Ideas, comments, and insights are welcome.

Pietenpol – A Bit of History

Filed under: Member Projects — admin at 10:57 pm on Saturday, June 11, 2005

by Greg Cardinal

from On Final June 2005

If you’ve been around aviation for any length of time you have probably heard of the “Pietenpol Air Camper”. The story begins in the mid 1920′s in Cherry Grove, Minnesota. Bernard Pietenpol (pronounced “BURN-erd PETE-n-paal) was interested in airplanes, as were a lot of other young people after the war. Charles Lindbergh’s flight ignited aviation passions even further.

Back in Cherry Grove, Mr. Pietenpol was tinkering with airplanes. Some were less than successful and finding an adequate, affordable engine was difficult. By 1929, Bernard had a viable airframe and an airfoil that he’d drawn out in chalk on a workshop floor (or so the legend goes). Henry Ford was selling Model “A” cars and Mr. Pietenpol was confident the Ford engine would be adequate in his airplane. After making a few modifications to the engine and mounting a propeller his plane flew very well. He built a second plane that also flew successfully.

Around 1930 or 1931, a Minneapolis based magazine, Modern Mechanics Illustrated, the predecessor to Popular Mechanics magazine, published an editorial denouncing the viability of automobile engines in airplanes as too heavy and under powered. Mr. Pietenpol informed the magazine editor that two airplanes were flying in Cherry Grove with automobile engines. The magazine editor challenged Mr. Pietenpol to fly the airplanes to Minneapolis for a demonstration.

Bernard and Don Finke flew them to Minneapolis. The magazine editor was thrilled with the airplanes and wanted to publish the plans in his magazine. No plans existed at that time so Mr. Pietenpol enlisted the services of his 19 year old neighbor, Orrin Hoopman, to draw up some plans which were subsequently published. The rest is history. Pietenpols have been successfully built the world over for more than 75 years. Some are still being built with Ford Model “A” or “B” engines. The Corvair and Continental A-65 engines are other popular engines.

In 1996 I purchased a set of plans and found an active support group on the internet with builders around the world including Mexico, the UK, Australia and New Zealand. In January of 1997 I cut the first pieces of spruce and plywood and started building ribs. In June of that year, Dale Johnson approached me and informed me that he had just built a workshop. He was looking for a project and offered to be my building partner.

This turned out to be a very good move on my part. Final inspection and sign-off was done on Saturday, May 21st. First flight was done on Monday, May 23rd.

We powered our Pietenpol with an A-65 and built 19 inch wire spoke wheels. It looks like an antique. Other features include hand woven wicker seat backs, burled black walnut veneer instrument panels, homemade compass and cowl latches. Chris Bobka has been closely involved with this project from the beginning and has done the initial test flights.

Based at Stanton, the aircraft looks right at home on a grass airstrip and it always draws a crowd whenever we take it out of the hangar.


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