K.Molson, H.Taylor Canadian Aircraft since 1909 (Putnam)
In 1915 Henry and James Hoffar, boat builders of Vancouver, decided to build an aircraft. They took as their general pattern the Avro 500 which they had seen in a magazine. However, the structure detail had to be designed and, since they wanted a seaplane, so did the entire float installation. Their successful single-float installation served as the pattern for the 1919 Hoffar float installation on the Curtiss JN-4(Canadian). These two were the only single-float installations designed in Canada.
The Roberts 6X engine selected to power the aircraft was a two-stroke six-cylinder inline water-cooled type rated at 75 hp. The 6X and the similar four-cylinder 4X were probably the most successful of the pioneer American two-cycle aircraft engines. They were made by the Roberts Motor Co, Sandusky, Ohio, originally founded by E. W. Roberts, a former assistant to Sir Hiram Maxim during his aeronautical experiments of 1893-94, to make marine engines.
The wing of the Hoffar H-1 was made of spruce. The front spar was of a solid D section while the rear spar was routed out for lightness and the ribs made from laminated spruce. Each panel was braced with piano wire. The fuselage was of spruce and ash cross braced with piano wire and had ash engine bearers. The tail surfaces were made of ash. The whole machine was covered with unbleached cotton except for the forward portion of the fuselage which appears to have been covered by sheet metal. There were no cockpit instruments. Construction of the aircraft, which had to be fitted in between boat building, took about four months.
Neither brother had flown but it was agreed that they should be able to get the feel of the controls by taxi-ing along the water and then should be able to rise, say, ten feet off the water. James Hoffar won the toss and with him on board Henry towed the H-1 to the centre of Burrard Inlet. The aircraft was taxied away for about a mile and then turned and headed back towards Henry in the boat. By the time the aircraft was abreast of the boat it was clear of the water and was soon at about 100 ft (30 m). This was not according to plan and alarmed Henry considerably. James made a flat turn near North Vancouver and headed back towards the boat, gradually losing altitude until he alighted on the water at full throttle about a hundred yards from the boat.
James Hoffar explained that the H-1 was airborne before he realized what was happening and he felt the best thing to do was to descend very gradually until he was on the water. The brothers taught themselves to fly in this manner and continued to operate the H-1 until the following year when, feeling its wires were getting too rusty for safety, they scrapped it, but the float remained in use for some time as a boat.
One 75 hp Roberts 6X. Span 36ft (10-97m); length 35 ft 1 1/2 in (10-7m) approx; height 7ft 1 1/2 in (2-32m) approx; wing area 330sqft (30-65sqm). Weights and performance are not known.