EAA Chapter 25

Chapter 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.

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!

by Christian Bobka

from On Final June 2005

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.

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.

by Jim Maloney

from On Final April 2005When someone mentions the word “warbird”, what images does it bring to mind? The sound of a Merlin engine, and flash of a P-51? The lumbering silhouette and drone of a B-24? When America entered the Second World War, every person and company in the country stepped up to do their part. Piper aircraft and its employees were no exception. They made a few modifications to inthe J-3 “Cub” and dressed it in olive drab. It was designated the L-4 (”L” for Liaison), and it was soon to become the most feared sight and sound a German infantry soldier could know.

Weighing less than eight hundred pounds, unarmed, and with a sixty-five horsepower engine, the Piper L-4 series carried two men and a radio, and could bring more destruction than a squadron of B-25s. While circling the battlefield, the pilot and observer would scout enemy positions. Then, using the radio, they would direct artillery fire to accurately eliminate those positions. They caused enough destruction, and were so feared, that the German forces offered a two week pass for R&R to any soldier responsible for the downing of a Liaison aircraft.

The only defense the L-4 had was the ability to stay below the tree line. They would try to get past any place they were open to ground fire before anyone could get a shot at them. When attacked by an ME-109 or FW-190, the slow speed of the L-4 could be employed to make quick, tight turns. This would force the faster fighter to overshoot. There were several occasions where German fighters crashed while pursuing L-4’s.

The last aerial combat over Europe was between an L-4 and a Fiesler Storch. The Storch and its crew were shot down by the L-4 crew. They were armed with nothing more than a Colt .45!

L-4’s were used in the Pacific theater and all other places the U.S. Army and Army Air Forces were deployed. Some were kept stateside to help train the pilots, mechanics, and troops preparing to go overseas. This was the mission assigned to “45-4809″.

“45-4809″ rolled off Piper Aircraft’s Lockhaven, Pennsylvania assembly line on April 12, 1945. The Army Air Forces accepted it into its inventory on April 16, and on May 22, it started a long journey to Sheppard Field, Wichita Falls, Texas. It made several stops along the way, and arrived June 24, 1945. It was assigned to the 3706th Base Unit, which was a basic training unit at Sheppard Field, but it was soon reassigned to the 2532nd Base Unit at Randolph Field, San Antonio, Texas. The 2532nd’s role was defined as “Pilot School, Specialized, Very Heavy”. The group moved to San Marcos Field, Texas, and the aircraft was stored there starting in January of 1948. It was then transferred to the 5th Liaison Group, which was part of the Tactical Air Command, based in Greenville, South Carolina. It remained in a storage state in Greenville until it was sent to the Civil Air Patrol in Rock Hill, South Carolina. The last active assignment was with the Civil Air Patrol in Little Rock, Arkansas. It was once again put into storage in June 1954. It was declared surplus in 1975, and purchased by Jesse Millerd of Little Rock. He fell ill, and my wife Sarah and I bought the aircraft in 2001.

I had just sold my Pitts S-1S and found the ad in Trade-APlane. With a pre-purchase completed by an agent, the report came in: “It’s not a creampuff. It won’t win Oshkosh by any means, but it’s a good old Cub that just needs cables.” A deal was struck, so I jump-seated to Little Rock, rented a Ryder truck, and drove to the Pine Bluff airport. When I saw the airplane I had to laugh. Obviously, I should have checked out the latest conversion factor on the word “rough”. We loaded the airplane, and on the way out of town I called my father-inlaw, Don Eide. “So? What’s it like?” he asked with excitement. “Well, Don… We’ve got a project!” Not the words he really wanted to hear. The word “project” was not as disturbing as the use of the word “we”. Twenty hours of driving later, the world’s largest aircraft model box showed up in Don’s driveway. “No glue needed! Batteries not included. May need some assembly. Ages 5 and up.” My lessons in aircraft restoration and rebuilding were about to begin.

The next day we were ripping fabric off the airframe and discovering more of what we had to work with. It seemed a shame to get rid of the red Naugahyde side panels and wing root covers, accented by black vinyl seats (it was like the worst possible country-western bar had a fire sale). The rear stick had a P-51 stick grip. The N number was adorning the tail in half-inch sticky N numbers (one side was even put on backwards!).

Upon inspecting the airframe, it became clear that a few feet of each lower longeron towards the tailpost would need to be replaced. All window glass would need to be replaced, and patterns for them would need to be made from scratch. The complete instrument panel, with shockmounted section , needed to be replaced. All four spars had cracks near the spar attach fittings. The butt ribs needed to be replaced, due to larger than normal screws used to hold the wing fairings on. A few leading edges were dented, and the false spars were suffering from some dissimilar metal corrosion where the aileron attach fittings pass through. At some point a PA-12 rudder had been installed, which has a different shape than the L-4, and needed to be replaced. The floorboards were good for patterns. The straps holding the fuel tank were installed improperly, but the problem had been fixed at some point by wrapping them in several rolls of duct tape to take up the extra space. Every day seemed to end the same way. A sigh, a shake of the head, and a good laugh at the question “What was someone thinking when they did THIS?!”.

There were a few positive aspects of the airplane. The original knob to hold the sliding window was still in place. The instruments were all original military. The kickplate curtain at the end of the floorboards was still installed, as well as the sheetmetal that the mag switch mounts to. When we removed the fabric from the right aileron, there were pencil signatures from Piper employees, dated 1944, and a few from the Civil Air Patrol members dated 1952.

Little did we know that the clock had started the countdown of a four-year restoration. It took the entire four years to strip the airframe to it’s very basic form, make all necessary repairs, and rebuild it from the ground up. After reassembling the major components, we covered the aircraft using the Poly-Fiber process. Every nut, bolt, screw, and washer was replaced along the way. Oh Å  and eventually we got around to installing the new cables!

There was very little paperwork with the airplane when I picked it up, so I placed a call to the former owner’s son. When he answered the phone, he was sitting at his desk pondering where he should send a folder he had found. The folder pertained to the airplane, but he was not sure what information it contained. He dropped it in the mail. It contained the original military logbooks, a i r c r a f t checker’s logbook, airframe and engine history data sheets, Civil Air Patrol logsheets, and a few miscellaneous pieces of military paperwork. We now had papers that had signatures of the instructors that took the airplane out, the students who were being taught, the crew chiefs assigned to it, and the mechanics that assisted them. There are squawks logged and greasy fingerprints left behind when they were repaired. We were no longer just rebuilding another Cub; we were returning a piece of history to the air.

During the four years of restoration, we spent countless hours researching the aircraft type as well as this specific aircraft. We contacted Maxwell AFB, and received a copy of the Air Force’s history card on the aircraft to complement the paperwork we had already received. Through the International Liaison Pilot and Airplane Association, I was put in contact with Major Jon Engle (son of famous aviator General Joe Engle, of X-15 and Space Shuttle fame). Jon was excited to see the history of the airplane. He took all the history cards and decoded all the numbers and abbreviations to produce a “plain English” version of the units it was assigned to, and the dates it moved. We then contacted Piper aircraft, who sent us a fax that contained a confirmation that the serial numbers on the wings and fuselage matched the ones installed on the airframe in 1945! They were also able to tell us that it left the factory in olive drab, with grey undersides to the fuselage, wings, and tail surfaces, and had a Beech-Roby prop installed. The L-4 “J” and “H” models were the only ones to use Beech-Roby props, and they were removed by the military due to maintenance costs.

The engine on the aircraft was a Continental O-170. This was the military designation for the A-65. The engine that was on the aircraft was the last engine the military had installed, and was documented as such.

It had not been run for quite a while, and not knowing the exact condition, Don pulled one cylinder to allow for a closer inspection. After he freed the first cylinder, we knew that it was time to pull the other three. Two of the four cylinders, pistons, and the associated rings had deep grooves in them. So deep that I could see them clearly from halfway across the hangar! After some extensive research and cost comparison, we decided to make the only deviation to authenticity. We decided that we would replace the engine with a C-85-8 modified with the O-200 crank and piston conversion. Since the aircraft will be operated mostly during summer months, we wanted there to be no question about the ability of the engine to make power, should someone pull out in front of us at a fly-in. We turned to Don Swords, of Don’s Dream Machines in Griffin, GA. He is very knowledgeable in small engines. He guaranteed the engine turns 97 hp at 2475 rpm. (A stock O-200 is only turning out 75 hp at that setting.) How does it all work? Don’t know, but we love the way it climbs! WOW!! What an engine!! He also took care of ordering the correct prop for the engine selection, and understood that we wanted to preserve authenticity. End result was a brand new 72 inch, 46 pitch (W72GK46), wood Sensenich propeller complete with the old style Sensenich Brothers decals.

The original cowling could not be reconditioned, so I started collecting new and used cowlings, in hoping a decent replacement could be found. While we were dry fitting the fuselage to the bootcowl and engine mount, we fit the pieces that we had acquired. No two pieces fit the same, and none of them fit very well. I contacted Tim Wood, of St Louis Aircraft Metal Arts, and he agreed to hand form a custom cowling from patterns we would send him. Don used the old cowling, trimming metal from places, and pop riveting aluminum where material needed to be added. We boxed it up and shipped it off. What we received in return was a perfectly fit, hand made cowling. He even hand made new nosebowl pieces!

If I were to write a book on aircraft restorations, there would certainly be a chapter devoted to things that surface in twists of fate. I would think a proper title for that chapter would be “What are the odds?!”

We had been researching the aircraft paint scheme for some time, and discovered that there was little known about paint schemes of continental service aircraft. Jon Engle had sent me a several pictures of liaison aircraft being used in the training command, and one that caught my eye in particular was a picture of Sheppard Field based L-2s in flight. Even the Army Aviation Museum sent me a CD with a copy of all the pictures of L-4s that they had. We wanted something that would make the aircraft more visible while in the pattern, without compromising authenticity. Don’s brother’s former boss was in the Army Air Corps during the war, and had taken some pictures of L-4s. Fortunately he still had the negatives! He sent us copies, and not only was the serial number of the photographed airplane close to ours, but the paint scheme was identical to the L-2s from Sheppard Field! We had it! When the airplane arrived at Sheppard Field, they painted the nose, rudder, and hubcaps white.

I racked up several hours making long distance telephone calls and sending emails all over the world, trying to track down a genuine RCA manufactured, AVA-120 reel antenna. This antenna was installed in the aircraft to be used with the RCA radios the military installed in the wing roots. The antenna consisted of a drogue cone that was attached to 125 feet of copper antenna wire. The wire was fed through an insulator attached to the rudder, and a mast through the Plexiglass on the left side of the observer’s seat. In flight, the observer would let out the antenna wire, varying its length to help “fine tune” the tube radios. The only example of the reel antenna I could find was located in a Canadian museum, and they were not going to part with it for any offer. Shortly after I had given up and located a person that built replica antenna kits, I found the genuine article on EBay and, oddly enough, it was at South Saint Paul airport. The person I bought it from had purchased it in England with some radio equipment, and did not know what it had been used for. To me it was like finding the Holy Grail of aircraft parts! We then finished the antenna using several copied parts, such as the drogue cone and antenna mast.

I was then out to find several other parts that were needed for the restoration. Still missing were the fire extinguisher, first aid kit, pilot’s checklist, and a Beech- Roby propeller pitch crank. I located a Fyr-Fyter brass fire extinguisher with mounting bracket on EBay, as well as a first aid kit. The fire extinguisher needed a good cleaning, and polished up nicely. The first aid kit was emptied of its contents and taken to the upholstery shop for sizing with the new seat covers. The container is the perfect size for storing necessary flying items, such as fuel strainer, Leatherman, and ear plugs.

Now I was riding on a high, and I was determined to find the remaining parts to complete this restoration properly. I started on another quest to find the checklist, checklist holder, and a Beech-Roby crank. Another round of phone calls and emails, even an ad on Barnstormers.com, and I was beginning to think I would not be able to find these items. Then during a phone conversation with a fellow restorer, I mentioned that I had all the manuals and logbooks, but could not find a checklist. His response was “Oh, I have one, but it’s for an L-4J.” “Wait a second … I have a ‘J’! I have a ‘J’! What do you want for the checklist?” There was a pause on the other end, and I thought I heard the sound of an adding machine in the background. “I’ll just send it to you.” Not only did he have the checklist, but he also had the drawings for the checklist holder!

The Beech-Roby crank was located in almost the same way. A friend of the family told me that he had a Beech- Roby adjustment crank, but he thought it was for a panel mount, such as a Taylorcraft. He had no use for it, so he would give it to my wife as a Christmas present (after all, it is her airplane, too). What he ended up handing her was the correct pitch adjustment crank, and it was still in olive drab paint! We decided not to install the crank during the restoration, but put it with all the other archival material we had found.

One of the big lessons I learned during the restoration was that sometimes you have to reinvent the small things, and sometimes it happens through reverse engineering. I found a pair of “new old stock” Piper production covers, with the tags still attached, and took them to an upholstery shop to be reproduced. I had to give them permission to take one completely apart to create a pattern. What they turned out was an exact copy of the original, but to make it more durable; they lined them with a heavy boat canvas.

During the war Piper used a both vinyl and olive drab canvas for the front seat covers. I contacted Beechwood Canvas Works in New Jersey, which still produces authentic WWII canvas for vehicle restorations. They sold me several yards of the canvas that was used for vehicle seats during that period. Carrying only canvas, pictures from the L-4 manual, dimensions, and an empty first aid kit container, I stopped at Metro Upholstery in Burnsville. They did everything I had asked for, and did a high quality finish. They turned out the front seat covers. We also had them make a set of square pads to be used in the back seat, since the seat was originally designed to be used while wearing a parachute.

My mother-in-law, Ellen Eide, used her sewing ability to duplicate the kick panel curtain. She used the old one as a pattern, and some of the O.D. canvas, to create a new curtain to be used in the restoration. In the design of the airplane, Piper extended the floorboards behind the rear seat to accommodate the observer while seated facing aft. At the aft end of the floorboards, they placed a kicker panel that is angled up. The curtain covers the area from the top of the angled panel, where it attaches with snaps, up to the map desk. It allowed access to interior sections of the aft fuselage for maintenance, while preventing unwanted objects from finding their way into the elevator mechanism.

On March 1, 2005, an airworthiness certificate was awarded to “45-4809″. On March 3, it made its return to the air, after fifty-one years of storage. Since Don Eide had done the most work, he took the honors of the first flight. When he returned, it took a couple days for the facial muscles to relax, and the smile fade enough for him to talk. He reported that it flew “hands off” the first flight. Sarah and I were able to fly it to the EAA meeting, and experience it for ourselves. It is, by far, the best Cub I have flown. We are looking forward to taking it to several fly-in’s, and to Oshkosh this summer.

There were many people involved in some way with the restoration of the airplane. We cannot think of everyone that had some influence, but there are a few that need special mention. One who had a constant presence was Mike Niccum, of Webster, MN. Mike is an A&P/I.A. who ended up overseeing the project. He did the final welding of the lower longeron repairs, and was our “go-to” guy whenever we had a technical question. He’s a top notch mechanic, and very knowledgeable in all airplanes, from aerobatic to warbird. Most of all, Sarah and I cannot thank Don enough for all the time and effort he put into the project. It would still be in the Ryder truck if it weren’t for his jumping into it feet first.

Now you will have to excuse me, but I had four years to daydream about my L-4… and today looks like a good day to go flying!

by Pete Gavin

from On Final January 2005

 

We last reported on Frank’s LEU project in September. At that point, he had framed up the tail feathers and completed the ribs and spars. For this update, I visited Frank’s project again and included material from his building log. As you can see, he has made a lot of progress over the past few months. Note: Frank has enlisted the help of Howard Longpre throughout this project.

Constructing the Wings
The most visible accomplishment since September’s report has been construction fabriand rigging of the wings. He has assembled the ribs onto the spars and constructed the remaining wing parts – the diagonals, D-sections, and leading and trailing edges. Frank says, “Getting all of these pieces cut to correct size and properly aligned and glued in place was like putting together a puzzle.”

They fabricated 18 false (foam) ribs for the leading Dsection. For these, they called on Marv Getten’s experience and used Marv’s special electric foam cutter. This is a homemade saw that uses a long wire to cut through multiple foam blocks at the same time. This ensures that they are of uniform size and shape. The leading edge consists of .8 mm plywood. Howard’s recommendation was that they make female forms to hold the plywood in place with straps while gluing to the leading edge ribs.

The aileron structures are built as part of the wing then cut loose for final assembly. They employed this same form and strapping method to apply their D-sections. The aileron pockets were strengthened with more plywood and closed out with poster foam-board material.

Frank commented that “Howard is a real treat to work with, and so capable…his machinists background is conveniently put to good use on the project.” Brass bushings were inserted in the outer aileron hinge blocks, and added into the design at various places. Both wings and ailerons were then finish sanded and varnished. Everything is now ready for the covering phase.

Rigging the Wings
The way the wings were originally designed, the leading edges of the wings were offset by about 1/8″ front to rear. This made it simpler to make up the wing attachments, but then the sections covering the gap between the wings would be slightly skewed. Frank corrected this by rearranging the attach brackets so that the leading edges came out lined up. This allows the sheet metal covering the gap to be square with the wings.

The initial wing alignment test was performed out on the lawn. Frank & Howard then moved the fuselage and wings into the living room for the rigging process. The initial trial assembly did not go smoothly. Both parasol attachment posts on the fuselage were slightly miss-aligned. It was impossible to get the bolts in both fore & aft brackets and through the posts at the same time. In the past, Frank had made several email and newsgroup submissions to the builder’s support group. This was the first time he actually grabbed the phone. After talking about the situation with John Bolding, there was only one option. Howard built a jig to help align and re-locate the parasol posts. Frank borrowed an acetylene torch to apply heat and bend the posts into position. They came out perfectly aligned.

They then built wing scaffolding and utilized a self-leveling dual laser to level the wings. The procedure was to level the wings, them move each wing tip up 3 inches for dihedral. They then affixed the forward strut attachment hardware. Instead of using the round struts per plan most builders are going with streamlined. Frank ordered streamlined struts from Carlson Aircraft. This project has all the basic attributes; translated this means there are gotcha’s. Howard had fabriancated the strut attachment hardware per the drawings. He found a place that did aluminum welding. They did a great job…problem was they only needed to have a seven degree angle, not fifteen. The wings and struts are now rigged.

The original design with the round struts required jury struts to keep the main struts from vibrating. These are not required with the streamlined struts, but Frank still intends to install them for extra strength.

Flight Controls
The control system mounts via nylon plate standoffs holding a one-inch aluminum tube that is positioned horizontally between stations 2 and 3. Brackets and guard shields fabricated out of AL sheet secure the 2″ pulleys called for in this control system. There is a riveted control stick shroud that mounts on the horizontal tube, and a control stick installed with bolt, washers, etc.

The elevator cable that goes through the horizontal tube is designed to pass by the bolts that go through the tube. Frank’s plane will use sailboat rudder and tiller blocks for the elevator and rudder cable fixtures through which the cables must pass to the tail. He is using a small brake lever from a local bike shop to activate the brakes. The lever was designed for 7/8″ diameter handlebars, which was ground out to 1″ for the control stick. A single hand lever will close both brake bands simultaneously; thus the brakes provide no directional control.

Once again, Howard has applied his creativity to Frank’s ultralight. He has fabricated most of the aileron bell cranks, rod, pulley guards, and spacers used throughout. He made some neat nylon/plastic stand off fasteners for routing the cable via brass fairleads fore and aft of the rear strut. These were machined such that each half will contour to the shape and screw together over the streamlined struts.

Frank borrowed the Nicropress tool (belonging to EAA Chapter 25), a cable cutter, and No-Go gauge from Chris Bobka. Wasting no time, they quickly fabricated aileron and elevator control cables to final length with turnbuckles for fine adjustment. Getting the cables cut to exact length can be a real challenge, and took more than one attempt in a couple of cases. These are now installed and ready to go. The day I visited they were starting on the rudder cables.

The fuselage still needs a few tabs welded to the fuselage for rudder pedals, standoffs and fairleads. Bert Sisler has agreed to help out with the welding once Frank decides on their final placement.

Fuel Tank
The tank is constructed of fiberglass and 1/4″ PVC foam. Frank’s was crafted by making a mock tank out of 1/4″ plywood from which the top laminate could be easily formed. The mold was lined with poly and tested for volume. The box was then disassembled and the pieces used for patterns in cutting the foam. The seven separate pieces of foam were laminated with the fiberglass on both sides. The box (minus the top) was glued together with epoxy. All inside corners were given radiuses of flox and more fiberglass which actually is both the structural and sealing surface, the epoxy is covered as most fuels will attack it.

After the box was constructed Frank installed the finger fuel strainer in the outlet. The filler tube is actually a household sink drain PVC tube. It is goes in the tank’s top before installing the top. From Frank’s experience working on his father- in-law’s Express project…he sealed the inside joints of all mating surfaces along the top with flox. The next challenge was finding a way to apply the same flox seal to the inside joints where the sides meet the top. He prepared curved strips of fiberglass and bonded them along the inside of the tank where the sides meet the top. He then filled the gap between the curved strips and the sides with flox, wetting every surface down with resin before pressing the top into place. The cover was weighted down with whatever ballast Frank could apply. It’s all done, and nice and light. It will be holding roughly 36 lbs. of fuel.

Engine
The engine was ordered from Hummel Engines while at Oshkosh. Delivered mid-October. It is a 1/2 VW full case upgraded to 1200cc. It has Nicosil aluminum cylinder walls keeping temperature down which translates into more horsepower. It comes with an Aerocarb carburetor, tuned manifold, exhaust, and a rotor-less distributor. It’s rated at 45 HP, and will probably be turning a 60 x 20 propeller. The engine has been run in a stand prior to shipment.

Fuselage Main Gear
The fuselage is standing on the main gear, and the wheels, tires etc. fit well. The design calls for compression springs over one of the cross support tubes, as one tube slides inside the other. Frank chose to use the stronger 1000 lbs. per inch die spring option. Some LEU builders have used valve springs from a diesel truck. From the advise of previous LEU builders, these springs are pre-loaded 1/4″ (or about 250 lbs.) Frank described the brake and axle work that remains.

Future Plans
Frank appears very eager to tackle the fabric and covering task, but will probably wait until the weather warms up. This generates a lot of fumes and one needs to be able to move a lot of fresh air through the workshop. Most of our m e m b e r s kn o w Frank…he loves to say “I am 90% finished, with 90% yet to go!”

One challenge that he is open to hearing about your experience with, is what to do about a tail wheel spring? Frank’s drawn up a sketch of what he thinks is needed, and is trying to find a shop that can fabricate it out of SAE 1050 – 1095 mild steel.

Stay tuned–more to come!