The creative Lieutenant Colonel Clark was a 1907 graduate of the Naval Academy. He learned to fly in 1913 at the age of twenty-seven, and took a post graduate course in aeronautical engineering from the Massachusetts Institute of Technology in 1915. Clark became the Chief Aeronautical Engineer of the U.S. Army from 1915 to 1920. During that time he served on every important aviation board or committee, including the new and prestigious National Advisory Committee for Aeronautics (NACA) and the Bolling Commission, which went to Europe to determine which aircraft the United States should build.
Lieutenant Colonel Clark became the first commanding officer of McCook Field, serving in the capacity during the crucial and fruitful days of 1917-18. Then the eccentricity surfaced. For some still unknown reason, he went on a marrying spree, and was ultimately court-martialed for more than forty counts of bigamy. The court-martial board apparently realized that his bizarre behavior was due to some mental or emotional problems, and only reluctantly separated him from the service, punishing him with little more than a slap on the wrist.
If Clark had never designed an airplane, he would have given aviation much, for his airfoils, which included the U.S.A. 27, U.S.A. 16, Clark V and Clark Y, were probably used on more American aircraft than any others up until well after the 1940s. They were adopted by foreign aircraft designers as well.
Another of his contributions was the invention of the Duramold process, which he created in cooperation with the Haskelite Company. The process used thin strips of wood veneer impregnated with synthetic resins which could then be molded into specific aircraft parts. Because Duramold takes such a sleek finish, it could also serve as a covering. It was in many ways the precursor of modern techniques with fiberglass. Although a number of aircraft used the material, the most famous was Howard Hughes’ huge flying boat, which, far from being built of spruce, was constructed of Duramold.
But Clark did design many aircraft, the most well-known of which was the Consolidated PT-1 trainer, which for many years was the standard Air Corps primary trainer, and which may be said to have put Reuben Fleet and Consolidated firmly on track in the aviation business. Unfortunately, Clark’s career, like those of many other great designers, was handicapped by the Great Depression which struck the United States in 1929, and which served to stifle aviation for the next ten years. There were tens of millions out of work, the aircraft industry was on the rocks, and many excellent designs failed to find a sufficient market, not through any inherent shortcoming, but just because business everywhere was so bad.
This was the case with General Aviation G.A. 43, a fast, efficient single engine airliner also known as the Clark G.A. 43 and the Pilgrim 150. The General Aviation Company itself was the product of a long, complex series of mergers, and had in its ancestry such important firms as the Atlantic Aircraft Corporation, Fokker Aircraft of America, Fairchild, Kreider Reisner, Berliner-Joyce, the Aviation Corporation (AVCO), and many others.
By skipping most of the organizational heritage we can go to 1931, when AVCO acquired the Fairchild Airplane and Manufacturing Company of Farmingdale, Long Island. It immediately formed a new manufacturing division, called the American Airplane and Engine Corporation, with Clark as general manager and chief engineer. It produced what was essentially a super-Fairchild, the ten places Pilgrim 100, which was used by American Airlines, an AVCO affiliate. It was the custom in those days for holding companies to own both airlines and aircraft companies, and to use their own aircraft on their own airlines.
American Airlines was nearing bankruptcy (some things never change) when the president of AVCO, Frederick C. Coburn, asked Clark and another engineer, George W. DeBell, to design a commercial airliner that might actually make some money.
The two men studied the problem and came up with two market niches. One was for a four-engine, forty passenger aircraft, while the other was for a single-engine, ten passenger aircraft. There was obviously less investment required for the latter design, which was also inherently less risky.
Clark and DeBell responded with the Pilgrim 150, a cantilever low-wing monoplane, with the single pilot cockpit enclosed and perched high on the fuselage. The all-metal structure had partial fabric covering for wings, ailerons, rudders and elevators. Unlike the ten-seat Boeing Model 247, there was no wing-spar running through the cabin. All ten seats (two rows of five) were comfortably spaced, especially by today’s standards, sat well above the structure.
Clark’s entire design philosophy was aimed at economy of operation, obtained by simplified maintenance and high cruising speeds. A variety of engines could be fitted, but the first aircraft had a Wright Cyclone R-1820 of 715 horsepower. A Pratt & Whitney Hornet engine would be installed in the last aircraft built. Clark wanted the aircraft to have a retractable landing gear, but a management argument within AVCO ensued, and he was fired. DeBell resigned in protest to the firing.
The Pilgrim 150 made its first flight on May 22, 1932, and while impressive in most respects, it achieved a top speed of only 175 mph. This was much less than anticipated and not enough to be attractive to the airlines. Clark and DeBell were promptly rehired, and they modified the aircraft with a hydraulically operated rearward retractable landing gear that resembled the pod-like installation used later on the Vultee Vengeance. Speed went up to 202 mph, and Clark was vindicated.
Unfortunately, the aircraft did not excite AVCO’s largest stockholder, E.L. Cord, who was currently marketing three of America’s most prestigious automobiles—Auburn, Cord and Duesenberg. He also controlled Stinson, Vultee and Lycoming. He felt that the Pilgrim 150 was unnecessary internal competition, and terminated production. The aircraft, and all rights and patents for it were sold in September, 1932 to General Aviation, of Dundalk, Maryland, the site of many famous aviation firms.
At General Aviation, the aircraft was slightly redesigned, with the fabric covering being replaced by metal and a larger vertical fin installed. Trailing edge split flaps were incorporated and the cockpit made large enough for two pilots with dual controls.
As was the custom in those less formal days, the aircraft, now called the Clark GA-43, was demonstrated at Wright Field. Flown by Captain Reuben C. Moffat and Lt. Ployer P. Hill, they reported that the airplane was the cleanest seen at Wright Field in a long time. (Hill was the unfortunate pilot killed in 1935 in the crash of the Boeing Model 299 [B-17 prototype]). The two pilots praised the G.A. 43 as “distinctly superior to any transport previously tested at this station, either single or multi-engine, in respect to performance, maintenance and flying qualities.” Despite the high praise, the Army did not purchase any for its own use.
Another series of corporate changes saw the firm renamed the General Aviation Manufacturing Company, which was soon merged with the failing Berliner-Joyce Aircraft Corporation, under North American Aviation, Incorporated, and then a holding company.
Work proceeded at a leisurely place, a shame, for what had been almost revolutionary when it was first flown was now merely competitive. The first production aircraft, construction number (C/N) 2202, was shipped to Cherbourg, France, for delivery to the Swiss Air Traffic Company, Ltd., the famous SWISSAIR. Designated CH-169, it had greater passenger capacity than the line’s faster Lockheed Orion transports, and was the first SWISSAIR plane to carry a radio. It did well over domestic lines and internationally to Germany, Austria and the Netherlands, and was liked so much that two more GA-43s were acquired by SWISSAIR. CH-169 (later registered HB-LAM) was sold in 1936 to an agent of the Spanish Republic. It served on the Spanish airline, LAPE, but had a landing accident and ended its days in Alicante, Spain. There, awaiting repair, it was reportedly destroyed when a hangar collapsed because of damage inflicted by the combatants.
In the meantime, the prototype aircraft (C/N 7500) was sold to Mitsui Bussan in Japan in 1934, probably intended for resale to the Japan Air Transport Company. Its advanced metal structure was carefully analyzed by Nakajima. It was then assigned to serve with Manchurian Air Lines, but crashed and was scrapped before entering service.
In 1934, the third GA-43, C/N 2203, was completed, and was used as a company test plane and demonstrator, prior to its sale to SWISSAIR in March, 1935. It was purchased at the same time as C/N 2004. Both aircraft were short lived. C/N 2203 wound up as a training aid for the investigation of metal structures. C/N 2204 (registered HB-ITU) crashed into the north-west wall of the Rigi mountain in central Switzerland on April 30, 1936, killing the pilot and radio operator. The accident was attributed to the failure of the direction finding equipment. Earlier in its life, C/N 2204 had been used by Western Air Express on its Cheyenne to Albuquerque route. Its usefulness in America was limited, however, because single-engine transports were restricted from night or instrument flight. It is probable that Western purchased the aircraft because of its corporate ties to AVCO.
The most exotic of the GA-43s was C/N 2205, which was equipped with big EDO floats and a controllable pitch propeller. This GA-43’s wings were specially strengthened to accommodate the floats, which each had a submerged displacement of 9,225 pounds. The floats were attached to the aircraft by individual mountings and had no spreader bar.
The airplane was the first U.S. seaplane to have wing flaps, and was further modified with a ventral fin (later removed) to offset the side area of the floats. It was delivered to Pan American Aviation Supply Corporation on November 19, 1934 for a bargain $42,000. Subsequently it belonged to the Sociedad Columbo-Allemania De Transportes Aereos (SCADTA), the famous German backed airline in Columbia. (At the time, German influence on South American airlines was regarded as a tremendous threat to national security, for it made attacks on the Panama Canal seem quite plausible. Pan American had secretly acquired control of the airline in 1930, a fact not known generally until 1940.)
SCADTA named the airplane Bolivar and flew it on its Caribbean coastal route, Baranquilla-Cienaga-Santa Marta, Columbia. On June 8, 1940, pressure from the United States forced the dismissal of all German employees from SCADTA. They were replaced by a specially trained contingent of Pan American employees. On June 14, the airline’s name was to Aerovías Nacionales de Columbia (AVIANCA) to reflect the departure of German influence.
The General Aviation Manufacturing Corporation had another card up its sleeve, a three-engine competitor to the Douglas DC-1. Designated the GA-38, it was supposed to carry sixteen passengers and have a speed of 195 mph. Charles A. Lindbergh was a technical consultant to Transcontinental & Western Airlines, which was considering the purchase of the DC-1. Lindbergh was skeptical about the safety and reliability of a twin engine passenger transport, which is ironic, given his single place solo flight from New York to Paris in 1927. The famous airman was invited by the famous Ernest R. Breech, then president and chairman of the board of North American Aviation, to examine the General Aviation GA-38 tri-motor.
The aircraft was incomplete, but it impressed Lindbergh enough that he recommended that work be continued on the GA-38 as a possible contender. Unfortunately, there was internal dissension in the company and the project was cancelled, even though $800,000 of depression-times money had already been spent.
Though only five G.A. 43s were built, they served on seven airlines and operated on four continents. More important, they were vital to North American Aviation, which moved to Downey, California, and proceeded to build a whole series of immortal aircraft.
Wingspan: 53 feet
Length: 43 feet 1 inch
Height: 12 feet 6 inches
Empty Weight: 5,300 pounds
Gross Weight: 8,000 pounds
Maximum Speed: 195.5 mph
Service Ceiling: 18,000 feet
Range: 500 miles
Engine: 715 horsepower Wright Cyclone
With thanks to Rick Allen, a true expert on the plane.