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ABSTRACT:     Article about a Skybolt built and flown by Glenn McElreath of Olympia, WA
Aerobatic Skybolt
This beautifully finished Steen Skybolt is one of the homebuilt stars of the Northwest
(From Sport Flying, 08/1979)
By Michael O'Leary
Photography by Jim Larsen

This beautifully finished Steen Skybolt is one of the homebuilt stars of the Northwest.
This beautifully finished Steen Skybolt is one of the homebuilt stars of the Northwest.

A bright white biplane, finished with an hour's worth of aerobatic flying over Washington's lush green forests, slips in for landing at Boeing's Renton Field. Perhaps the sight of a small biplane among those giant metal tubes manufactured by Boeing is a bit incongruous but the group of partners that own this very clean little bipe are, or have been, all employed by Boeing.

The aircraft is a Steen Skybolt and is certainly one of the finest examples of the aircraft flying. The Skybolt was created by Glenn McElreath in Olympia, Washington, and his methodical method of construction and finish took five years to complete the superb example. Glenn spared no expense on his project, the second homebuilt that he had constructed, various subassemblies were sent out to subcontractors who were noted for fine workmanship. The fuselage was welded by an expert, the spars were created by a craftsman, and the finish was applied by a master. Glenn worked closely with the creator of the Skybolt, Mr. Lamar Steen who advised on the project and contributed much vital information.

Lamar Steen originally designed the two-seat fully-aerobatic biplane as a school class project in Denver, Colorado. Because of the fact that students were working on the design, Steen made sure that his drawings were easy to follow and that the construction was rugged yet simple. Steen started the design of the aircraft during the middle part of 1968 and construction took its first step on 19 August 1969. The school class put the two-seater together for a cost of about $5,000. First flight of the design, to be named Skybolt, took place during October of 1970.

The aircraft exhibited excellent handling qualities and no problems were encountered. The Experimental Aircraft Association was so impressed with the Skybolt that they awarded the design a trophy for Best School Project. The prototype was powered by a Lycoming HO-360-B1B of 180 hp and the airframe is stressed for engines that range from 125 to 300 hp. Construction consists of wooden-braced wings that are fabric covered. The fuselage is welded chrome-molybdenum steel tube as is the tail unit and they are also fabric covered. The 180 hp version achieved a top speed of 145 mph with a cruise of 130 mph. Maximum takeoff weight is 1,680 Ibs with a useful load of 600 Ibs. The top wing spans 24 ft while the lower unit is 23 ft long. The wings have a total area of 152.7 sq ft. Overall length is 19 ft and the service ceiling is 18,000 ft with a maximum range of 450 miles.

The Skybolt that Glenn McElreath constructed is powered by a six-cylinder 220 horse Franklin that was offered in kit form to homebuilders. The Franklin engine company, struggling to stay financially afloat, decided to offer this engine in both certified fully completed form and in the uncertified disassembled kit form. Thus the homebuilder could gain an intimate knowledge of his powerplant while saving a few bucks. After Glenn purchased the kit engine, he had some of the finest engine people in the business help put it together.

The aircraft is now owned by four partners: Del Underwood, Brian Wygley, Ken Higgens, and Walt Raby. All are ATP rated and use the sturdy biplane most frequently.

We talked to Boeing sales representative Del Underwood who really enjoys flying the Skybolt. "I've taken the Skybolt to a number of airshows," said Glenn "and it has picked up trophies. I had the plane down to the Porterville, California, Skybolt fly-in and, by looking at the 15 to 20 other Skybolts in attendance, I was able to see what a really first class job Glenn did when he built the plane." Del had flown a number of other biplanes including Stampes, Tiger Moths, and Pitts so the Skybolt did not present any particular problem although "each aircraft of this type is different and it takes a bit of getting used to its own individual characteristics. No two homebuilts fly alike."

Del particularly enjoys the operation of the six-cylinder Franklin.

"The powerplant is as smooth as a Rolls-Royce and, I think, offers the best power-to-weight ratio of any of the Skybolt powerplants. The larger 260 hp Lycomings weigh too much and cause a bit of a cg problem. Extra weight has to be added to the tail to compensate for all that weight in the nose, thus the big engine versions are heavier and, I feel, not as finely tuned when doing aerobatics."

Del views that Skybolt as having few vices. "The aircraft is perfectly straight and could be flown easily by low time pilots that get a thorough check out." Del's average flight covers about one hour and usually includes giving friends rides, performing some aerobatics, and airport hopping. "The countryside of the Seattle area is absolutely beautiful," states Del "and this type of aircraft is the perfect airplane to enjoy the scenery."

Del feels that aerobatics in the Skybolt are just about equal to the Pitts S-2. The performance is about the same even though the Pitts is smaller, lighter and has less horsepower. Del feels that the Skybolt, because of its larger size, performs aerobatics in a smoother manner than the Pitts. "The larger size of the Skybolt also makes it more visible to the airshow crowd which is a plus on a hazy day," says Del. The Skybolt is equipped with a full smoke system and has been used for some airshow work. Del and his partners look forward to many more hours aviating in the Skybolt for, as he puts it, "The Skybolt is an ideal aircraft for sport flying."

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