Rare Birds: Boeing GA-X

Boeing GA-1

Boeing GA-1

The unlovely and unloved Boeing GA-X was one of those crazy hybrids of the early days of aviation, an awkward mixture of brilliant vision and adolescent engineering which looked formidable on paper, but proved impossible in the air.

Boeing has always been quick to point out that the GA-X design originated with the Engineering Division at McCook Field. The original Air Service requirement for an armored ground attack aircraft had been submitted to no less than fifteen domestic manufacturers on October 15, 1919. Basically, the Air Service contended that the ground attack role called for either a heavily armored aircraft with great firepower, or a smaller aircraft, faster and more agile. Given that the mammoth orders placed for aircraft in World War I had all been canceled, one would think that the manufacturers would have competed intensely for the job. They, however, saw that the task was beyond the current state of the art, and it was left to the Engineering Division to design the aircraft and build the first prototype.

The mission was seen as laying down an unprecedented rate of fire from an invulnerable aerial fortress. Arms and armor meant weight, and that meant a lot of lift was required. More wings was a solution for many of the early designers, as witness the Armstrong Whitworth and Pemberton Billing quadraplanes, Tony Fokker’s ill-fated quintaplane and the nine wings of the Caproni Ca 60 Triple Hydro-Triplane. Unfortunately, more wings means not only more weight and drag, but often inflicts control and stability problems on the design.

The designers of the GA-X settled for the tri-plane configuration to provide adequate wing area. It was seen early on that at least two engines would be required, and by 1919 there were so many 435 horsepower Liberty engines in stock that no other alternative was considered. These were mounted as pushers, swinging four-blade propellers. Isaac M. Laddon, the designer of another, more famous and successful pusher (the Consolidated B-36) was called into supervise the general design of the aircraft.

The principal firepower of the prototype GA-X was a 37-mm Baldwin semi-automatic cannon, installed in a visored swinging turret that could have been designed by Prince Valiant. (The Baldwin was replaced by a Puteaux in production aircraft.) The cannon was operated by the front gunner, and could be defelcted 45 degrees too the right or left, as well as 60 degrees down and 15 degrees up. The front gunner also controlled five .30-caliber machine guns. Four pointed down, with a limited degree of travel, and were intended to chew up troops in trenches. This was an installation favored by the laboratory types, but one that rarely worked out in practice. A fifth .30-caliber gun was mounted to fire to the rear, over the top of the gun. The rear gunner had two more floor-mounted .30s, intended to finish off any stragglers, and another similar gun for upper defense. These eight machine guns and one cannon made the GA-X (Ground Attack, Experimental) a flying Maginot Line.

Despit the unique layout, the most sophisticated element of the GA-X was its use of 3/16” thick Eddystone armor plate as an integral part of the cockpit and nacelles. This echoed the construction principal of the Junkers J-1 and prefigured that of the Ilyushin Il-II Sturmovik.

Despite the three wings, the aircraft was actually reasonably clean. The profusion of N Struts created a very rigid structure, one that funneled vibration directly into the cockpit. The genial, erudite Lt. Harold R. Harris was test pilot for the aircraft, and he used to roar with laughter when he recalled the incredible din of the thundering Liberty engines, which, amplified by the whistling wires and the resonance of the armor plate turned the cockpit into the what he called “the inside of a drum.”

Boeing won a service test order for twenty aircraft, but Harris’ final report of October 21, 1920 was so adverse that the order was immediately reduced to ten. Harris, who actually set altitude records in the Barling Bomber and flew the first pressurized cockpit in history, later became a Brigadier General and eventually head of Northwest Orient Airlines. A tall, rangy man with a twinkle in his eye, Harris in his later years had a tremendous sense of humor and the delivery of an expert stand-up comedian. In his report, he noted that the aircraft was overweight and underpowered. At 8,740 pounds, the takeoff roll was 885 feet, which sounds STOL today, but was then regarded as too long for operation close to front lines, as was intended. Maximum speed was 109 mph, but cruise was 89 and stall 64.

Harris reported that the airplane was inherently dangerous for its assigned mission because its small margin of power, poor cockpit visibility and a nasty tendency toward spiral instability. Losing an engine meant landing quickly, for the single-engine performance was a toboggan like slide to the ground. Harris also believed that wooden pusher props were too vulnerable to the debris thrown off by the vibrating Liberty engines. He commented that the controls were stiff and the airplane was fatiguing to fly, especially because of the intolerable noise level. A twenty-minute flight was said to be sufficient to induce deafness for twenty-four hours.

Despite the devastating reports, Boeing built ten of the aircraft (now designated GA-1) and shipped nine of them to the 90th Attack Squadron at Kelly Field, Texas, with the tenth going to Fairfield Air Intermediate Depot—now the Patterson of Wright-Patterson Air Force Base.

The 90th Attack Squadron solved the initial problem of what to do with the GA-1 aircraft in typical G.I. fashion. Only one was assembled, and it was rarely flown. The other eight remained firmly packed in their shipping cases. General Billy Mitchell himself suddenly brought life to the program, however, by demanding that the GA-1s be modified so that their guns could be demounted and attached to tripods. His plan was for the GA-1 to over-fly enemy positions, land, mount the guns on tripods and hold the ground until relieved by advancing infantry.

One can imagine the general lack of enthusiasm among pilots for Mitchell’s plan, but nonetheless, four more GA-1s were assembled. To make them more flyable, all armor and armament was removed, taking away even the slight bit of utility the aircraft possessed. A new lightweight, less drum-like nacelle was installed. It was rumored that the principal mission of the GA-1 was switched from ground attack to disciplinary, for if an aviation cadet fouled up, he was threatened with having to fly the GA-1 as punishment.

Interest flared again in the aircraft when the Mexican Consul General expressed an interest in buying them, presumably to pursue rebels. General Mason Patrick eagerly telegraphed that he would sell nine GA-1 aircraft for $15,000 each, but for some reason the deal fell through. On April 7, 1926, all GA-1 were ordered salvaged, to everyone’s relief.

One might have thought that the GA-1 experience might have been enough for the Engineering Division and Boeing, but they followed up with the GA-2, a truly ugly biplane powered by a single experimental Engineering Division W-18 engine of 750 horsepower. Boeing built two of the aircraft, the first strictly to Engineering Divisions’ plans the second modified to suit the experience gained in building number one. Armor was employed as on the GA-1, as a part of the structure. The two aircraft were shipped to McCook Field for testing. Top speed was a creditable 113 mph, given the excessive drag that the multiplicity of struts engendered. It was powerfully armed, ith six machine guns and a 37 mm cannon, but, like the GA-1 was unpleasant to fly and soon abandoned.


Upper Wing span: 65’6”
Middle Wing Span 62’0”
Lower Wing Span 58’6”
Length 33’ 7-1/2”
Height 14’ 3”
Empty Weight 7,532 pounds
Gross Weight 8,740 pounds
Maximum Speed 105 mph
Cruise Speed 89 mph
Stall Speed 64 mph
Endurance (full throttle) 108 minutes
Service Ceiling 11,000 feet

Leave a Reply