By Paul Swan.
[Ed. Note: This article first appeared in the November 1972 issue of FLYING.]
It has been almost a half-century since the first Gormley-Bulsh Blowfly rolled out of a small, white frame factory in Aldershot, England. Built at the request of the Italian Army, it was intended for use as a defensive weapon against German observation balloon attacks.
The Gormley-Bulsh people were well- known automobile manufacturers, but had no experience in the new-born aviation industry. This led to one of the most unusual features of the Blowfly--its four- speed transmission (one speed in reverse). The company's chief engineer, Sir Ian Hickey (later to become Mr.Ian Hickey), had proceed- ed along familiar automotive design concepts; his inclusion of the transmission in the airframe design was not discovered until the prototype had already been completed. As the Italians were most anxious to combat the threat of the German balloons, Gormley- Bulsh decided to go ahead with Hickey's original design.These transmissions used straight-cut, nonsynchromesh gears, necessitating additional flight instruction in double-clutching.
Vee belts ran from the transmission pulley to the propeller assembly, mounted above the radiator, to provide the final drive. Another of Hickey's mechanical innovations was the use of burled walnut exhaust valves. These beautiful, hand-turned valves gave the Blowfly a distinctive and not unpleasant castanet-like chatter at idle. The presence of the transmission enabled the designers to employ the standard automotive cranking system in starting the engine. After the engine had been started, the clutch was engaged and the plane could then be taxied in low gear, via a steerable tailwheel. Lubrication was by a rather primitive splash system, which caused the engine to smoke badly whenever it was operated at any speed over 100 rpm.
When compared with other aircraft of the day, the Blowfly's performance was not spectacular. Its top speed of 47 mph (in top gear) was found to be inadequate, especially when coupled with the somewhat severe glide ration of 3:1. The operational ceiling of 420 feet, however, provided to be of some defensive value: German antiaircraft gunners were reluctant to use explosive shells at this low altitude for fear of causing casualties on the ground.
Instrumentation consisted of a tachometer that was redlined at 200 rpm, and a barometer/altimeter of the ever-popular "Witch-and-Children-in-the-Cottage" model. Peak altitude was indicated when the witch came all the way out of the cottage. An oil-temperature gauge was installed in the prototype, but as the oil rarely remained long enough to become very hot, it was felt that this instrument served no real purpose; it was not included on the production model.
The three-cylinder, water-cooled, in-line engine was the same the company had been using in its fantastically unsuccessful two-passenger drop head couple, the Bolide. the engine was rated at 26 bhp, but again, this figure was never actually reached in the production engines because of various material limitations, including the fact that the valves had a tendency to splinter at high revs. Many components of the Bolide automobile were used in the Blowfly: the muffler, radiator, windshield, horn and hood ornament.
An interesting aside to the history of aircraft development was recorded on October 12, 1915, when a Blowfly was used in the first successful test of a phonograph in an airplane. The failure of the Royal Signal Corps to pursue this line of research further was instrumental in assuring the radio's early domination of aircraft communications.
By the end of the war, a total of seven Blowflys had been built at the Aldershot plant, two of these actually being delivered to the Italians. Only one of these planes was ever involved in actual combat. On November 9, 1917, Lt. Giuseppe Imbroglio, a member of the four-man *Dolce Far Niente* squadron,was flying a patrol mission, his first in a Blowfly. He reported that while flying over the Tolmino-Caporetto Sector north of the Bainsizza Plateau at an altitude of 350 feet, he was attacked by a German observation balloon. What ensued was to be the longest recorded dogfight between a captive balloon and an airplane. After a number of furious onslaughts, the Blowfly was brought down when it was hit by a map case thrown by the German observer. Lieutenant Imbroglio was able, by skillful down shifting, to bring his ship to a relatively safe landing, but records captured during the latter stages of the war indicated that the German observer was badly shaken in the encounter and was sent back to Berlin for R&R.
Even though Imbroglio's was the only Blowfly involved in combat, the Germans claimed the destruction of 27 of the planes! It was later determined that this error was due to the plane's smoky lube system: What the Germans had seen was the *same* Blowfly 27 different times, trailing a smoke cloud as it cruised toward its home base.
It is unfortunate that no Blowfly has survived. The last known example saw
some use in 1923 after having been converted to a cropduster, but as the oil smoke tended to damage the crops, it was shortly taken out of service. The engineering team responsible for the design and production of the Blowfly remained neutral during World War II, at the urging of the British Government, so there was no chance for development there. The last Blowfly was last seen in late 1956 filled with helium, being used to promote the opening of a supermarket in Grimsby. An ironical use of the machine designed to be the scourge of the balloon! On this same occasion, a sudden squall caused the mooring lines to the floating Blowfly to part, and the sole urvivor of the breed was seen drifting out over the North Sea, where, presumably, it finally fell.
One of my most cherished possessions is a polished mahogany gearshift knob embossed with the famous Gormley- Bulsh emblem. A silent *momento mori* of the gone but not forgotten Blowfly.
