Ten years ago 3 of us in the Omaha club each built Skylarks. We all built at least one from the Sterling kit in the 1960s or 70s and wanted to revisit the experience. Mine is the red one (Monokote on the flying surfaces; Lustrekote on the fuselage). Wade Pearson built the dark blue one and his dad Don built the yellow one. The red and blue models are still flying. I have several hundred flights on mine, with at least six different engines (FP .35s, FP .40s and LA .46s). Its a little on the heavy side and the .46 flies it best. I really like the run characteristics of this engine.
The "project" began in late May of 2000. We briefly considered doing the larger version from A&D Design plans, but quickly settled on the kit version because we had all built one before (I had 2 in the mid 1960s). The Pearsons financed all the wood, glue and hardware. I used partial Sterling kits plus one pristine reference kit as guides and cut 4 kits. One of those was set aside as a "template kit" in case we screwed up some assemblies and needed to cut more parts. I still have that kit. The Sterling kits were sold on eBay to recoup some of the cost. The 3 of us framed up our models in my shop, then Don and Wade took theirs home for finishing (with silk span and Brodak dope).
For a variety of reasons, the project dragged on for over 2 years. Wade's Skylark flew first in June of 2002. Mine was done in mid July and Don's in late August. I think mine is the only one to have flown in local contests (Topeka KS, Polk City IA and Sig). I've considered revisiting the project, this time doing the larger version from A&D Design plans. For now I'm just cleaning up the template kit and restoring some missing parts to a partial Sterling kit I recently acquired. I currently have 5 sets of Skylark plans from various sources. A good flying and most likely Classic Legal model could be built from any or these plans, but there are important differences among them and no 2 are alike. A set I recently bought on eBay may be the original M.A.N. plans.
When building our Skylarks we tried to duplicate the Sterling kit as closely as practical, but there were many details we just had to change. Some of the kit ribs appeared to be incorrectly shaped. If used "as is" one or 2 ribs would be "pitching a tent" midway between the center of the wing and the tip. I trued up the rib templates to create a gradual taper in wing thickness from the center to the tip ribs.
The 1/6" plywood fuselage doublers were replaced with 1/32" and these were continued back to about 1" past the trailing edge of the wing saddle. The motor mounts were extended to about 1 inch past F2 and a 3/8 cross grain balsa block was epoxied between them. The kit also included 1/8" balsa doublers which we either replaced with 1/16" balsa or eliminated. The nose of this design is probably overbuilt, but it does make for a solid front end and absorbs vibration.
I think we all used a 4 inch bellcrank and taller control horns than shown on the plans, especially the elevator horn. I "floated" my bellcrank pivot pin between 2 pieces of 3/32" plywood. Wade and Don may have used the traditional 1/8" plywood plate. Pushrods were 3/32" MW, CF or fiberglass. We all used "larger than stock" aluminum landing gear so the models could be easily flown off low cut grass with 2" or 2.25" wheels and still clear an 11 inch prop. Two of the partial kits had usable canopies. I gave these to Wade and Don and used a Sig Mustang canopy on mine. Any 8 or 9 inch bubble canopy would be a good substitute.
The cowls were reworked to mount with plywood tabs on the side of the fuselage (like the ARF SV-11) and with no internal structure to hinder airflow. I extended the rear of my cowl to cover the landing gear mount plate. Tanks were made removable or "semi-removable". The engines were mounted on 1/8" ply or metal plates to allow for some tank height adjustment. We all added line sliders and tip weight boxes. I added an adjustable rudder to the fin. The kit plans recommend rudder offset, so it should be Classic Legal, but I made it removable in case the Classic Police disagreed. It has never been questioned at any area contest.
The 2 Sterling kits I built in the 1960s were brush painted with many coats of Aero Gloss and probably weighed about the same as the one I'm flying now (55 ounces). They were underpowered with my McCoy .29 and .35, but I enjoyed flying them anyway. If I build another, one goal would be to take out a half-pound of weight, or build a larger version to equal or less weight than the smaller one. EWP
Topic: Skylark information wanted (Read 3283 times)