This is an update on the restoration of the only factory built Schweizer SGU 1-20, NX-91840 by Guy Byars and Jim Miceli in Cincinnati OH. See the Summer '94 Bungee Cord for a description of the project.
In preparation for the restoration work, I began building my own "Aircraft Restoration Shop" in my back yard. When we picked up the glider in late March, we could not do much work on it until the shop was operational. At that time, the contractor had just poured the 26'x28' foundation. He then quickly put up the walls roof and doors. However, there was much work to do to turn this shell into a proper shop. Between early April and mid July all my free time was spent adding a 65 amp electrical service, natural gas service, insulation, walls, lights and ceiling. After painting the floor with shiny gray urethane hangar floor paint and installing a 30,000 BTU natural gas fueled unit heater, I brought in a 16" band saw and belt/disk sander which completed the shop.
Work on the wings finally began in mid-July. We had a serious setback when our A/I inspected the basic work which had been done on the left wing which came with the project. He found a some minor problems and several serious ones. All of which could be fixed, but given that we had to build a new right wing from scratch anyway, Jim and I decided to build up two new wings instead. It isn't that much more effort to do two instead of one and this way we could be sure they both would be the same.
While Jim began looking into the metal work, I started with the wood and began making wing ribs. There are 38 ribs in the glider, 16 of which are in the tapered section of the wing. For those tapered ribs, after you build two ribs, you have to make a new jig. It was slow but enjoyable work and the complete set was finished in November.
We also need to make new spars. Since you can't buy 22' long straight grained clear Stika spruce boards at Home Depot, we found a lumber yard in Madison Wisconsin which had the necessary wood. I decided to combine the spar trip with a visit to Oshkosh. We left Cincinnati with an open 1-26 trailer in tow to carry the spar blanks back. We spent Friday at the Oshkosh Airshow and saw only a small fraction of all the stuff there. We ran into Jan Scott who had his beautifully restored Minimoa on display. I also met Roger Gomoll who was helping with the SSA booth. He is a partner in one of the other two existing 1-20s. He offered to let me come over and look at his 1-20, but unfortunately, time didn't permit.
We left Oshkosh early the next morning and arrived at the lumber yard in Madison at 9 am. There we found several huge bins with spruce boards standing on end in lengths ranging from 12-19 ft. Many of the boards were not of aircraft quality, some had knots in the wrong place, others were warped. Still, after spending 2 hours looking through over 200 boards, we finally picked out 9 of the best 18'-20' boards. This was more wood than the project required, but we assumed that we would accidentally ruin a few boards, so we wanted some insurance. Plus, any good straight grained spruce left over could easily find a home with one of the many local homebuilders in the area. As we were packing up the lumber on the 1-26 trailer, a man came in looking for 18' Stika spruce boards for his sailboat mast. He was not at all pleased to see 9 of the best boards leaving on our trailer!
The 1-20 spars are very complex. They have several different tapered sections and are also beveled to the contour of the airfoil in the outer half. This necessitates a great deal of careful exact measuring and hand planing. To help with this process, friend and club member Henry Meyerrose, a professional contractor, generously offered the use of his well equipped woodshop. Henry also has experience restoring gliders back in Germany in the 1950's. Friends like that are a great asset indeed!
We began by running all our spar blanks through Henry's planer and brought them down from the rough 1" stock to the finished 3/4" thickness. Then we used his joiner with its 6' bed to straighten one edge on each of the boards. The "insurance" of having a few extra boards really paid off when we ripped one board down from 5-1/4 inches down to its finished width of 4". When we removed a 1-1/8 piece, the board went from being perfectly straight to being severely bowed. Although the grain looked good on the surface, there must have been residual stresses which caused it to bow when cut. The board could not then be used in the glider, but was great to practice our splicing techniques on. The splice scarf joints were made with the aid of a steel jig fabricated by Jim. This jig held the spar end at exactly a 12 to 1 angle as we ran it through the joiner. The splice joints came out perfect. As of this writing, the we have finished shaping the front spars and are finishing up the rear ones. Just last weekend I added the doublers and small plates on each front spar. Assembly of the wings will begin in a few weeks and should proceed quickly.
Much progress was also made over the Christmas Holidays. When I went to visit my parents in Clemson SC, I took the tail surfaces and ailerons with me. I worked on them in my father's, Ed Byars, shop. He is currently restoring a YKS-6 Cabin Waco and his shop has all the facilities for aircraft covering work. During that week, we cleaned/stripped/sand blasted and painted the metal tail surfaces and the metal hardware in the wooden ailerons. Then we then covered them with the lightweight (1.7 oz/yd) Stits P-106 fabric. The light cloth was very thin and flexible and was a joy to work with. It laid down easily even around tight corners. After a week of steady work, the tail surfaces and ailerons are now covered, taped, and ready for the final clear coat, then silver.
Meanwhile, we were able to locate a set of vintage instruments. We found a Robinson pellet variometer, an early compass with a "fishbowl" front glass plate, a low speed Kollsman airspeed and a matching Kollsman altimeter. All the instruments are in good shape, but still need to be sent off for overhaul, clean up and repainting. We also acquired a set off brand new military style seat belts and shoulder harnesses. Although the 1-20 didn't have shoulder harnesses originally, we decided to sacrifice originality for safety in this point.
My research into the history of the 1-20 has also gone well. After some detective work, I located two color photographs of the 1-20 taken at the 1946 Nationals at Harris Hill. The 1-20 was 2 weeks old at that time. Special thanks to Jack Perine of Berryville VA for taking the time to make copies of those photos available to us. From the photos, paint chips, and descriptions of the colors from Paul Schweizer and others, we determined that the original colors were a cream base with A/N blue trim. This pleased us because we initially had thought that the original paint scheme was a boring solid yellow. Also, those photos were critical in determining the original trim lines and N number sizes and styles. Thanks again Jack!
After the article announcing the restoration of the 1-20 appeared in the Bungee Cord last Summer, I got several interesting letters about it's history. My favorite story is about it's last flight. It belonged to a club where it sat outside on an open trailer for a long time. One day several club members decided to "air it out" and fly it. The lucky pilot landed and said "The wings sure do bend a lot". Upon inspection, they found the spars outboard of the struts were rotten. Lucky indeed! Many thanks to those who sent me letters. My delay in answering was not for lack of gratitude, but simply because I have been spending every spare moment out in the shop driving little nails into gusset plates on 1-20 ribs!
Our goal is to have the 1-20 finished by next July for the 1995 International Vintage Sailplane Regatta at Harris Hill. While we don't want to compromise the quality of the restoration just to make that date, we are working hard to be there then. Wish us luck!