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Canada’s First Helicopter

 

Helicopter

The following excerpt from the narrative by A. J. Doug Angus of Winnipeg, Manitoba, tells the story:

Three brothers, Douglas, Nicholas, and Theodore Froebe, living in the Homewood area of the [Manitoba] Province, had a keen interest in flight, not only by learning to fly the aircraft of their era, but also delving into the much more technical aspect of constructing “flying machines” of their own design.

Early in 1936, after gaining much valuable experience with various designs of flying machines, the brothers decided to experiment with vertical flight of heavier-than-air craft. The undertaking that followed was the result of a thorough review of all the books and literature they were able to accumulate on the subject of helicopter flight at that time.
Although their design was never registered at the patent office, they did spend much time and money doing research on existing patents of a similar nature. There was always the pressure of someone else coming up with a similar design before they could complete their own. The end result, to quote Douglas Froebe, “The second search was more expensive but was of little help and contained so many different patents that it discouraged us of ever trying to get a patent at all.”

To begin the transfer of their helicopter design from paper to actual fact, the frame was constructed of aircraft chrome molybdenum steel tubing obtained from the McDonald Aircraft Supply Co. in Winnipeg and assembled in a roughly “T” shape. This, along with many hand-crafted parts which they fashioned themselves (there was no other source available) became the “Froebe Helicopter.” 

Helicopter

The finished product was left uncovered as it was still in an experimental form, but was very well designed and constructed. The craft was quite an accomplishment in comparison with other designs of that time.

The power source presented a problem, but the following winter while on a trip down to Los Angeles in a 1937 Ford, a #737 Gypsy engine was purchased for the helicopter. The engine was purchased from the nation’s largest used plane dealer, Charles Babs. It had been used on a Great Lakes biplane trainer and had only been run for 17 hours. Charles Babs showed quite an interest in their project and he almost gave them the engine, only charging $100 for it. All that was missing was a magneto distributor cover, which was later obtained from a North Hollywood airport on their way back home.
While looking around the North Hollywood airport, a plane on the field caught their interest – a Curtiss Robin airplane with a six-cylinder Challenger engine, and gas tanks large enough to hold fuel to fly the Atlantic Ocean. Later, they realized they had seen “Wrong-Way” Corrigan’s plane that he used on his famous flight to Ireland.

The #737 Gypsy engine, which was to supply the power for the Froebe helicopter, was installed in the forward section of the fuselage and connected to the rotor shaft through a right-angled drive. Fuel for the engine was contained in a small tank originally installed immediately behind the engine. This additional forward loading adversely affected the balance, so the tank was relocated behind the pilot’s seat for better weight distribution.

Lift for the craft was accomplished by the use of two concentric counter-rotating foils located five to six feet above the fuselage, with directional controls embodied in the upper rotor assembly. Much thought and research are evident in the design of the rotors. This can be seen in the original sketches of a rotor (Clark-Y foil) section, made on the back of an old blueprint that’s now in the archives of the [Western Canada Aviation] Museum. These sketches bear similarities to the designs in use today – a tribute to their advanced technical thinking. 

Helicopter

Although the craft lifted free from the ground, any successful controlled flight was marred by severe vibration as soon as the craft was airborne. Short directional flights were achieved, but always with the accompanying excessive vibrations.

On December 20, 1938, an entry of some interest was made in the logbook: “Motor could only turn to 1400 revs, with two degrees of vane pitch. Several jumps were accomp­lished with all three wheels off the ground at the same time, and the rear wheel off about six times, the highest being about three feet. No failures were encountered.” A great deal of further experimentation followed, and early in 1939 an entry in the log reads: “Lift was better at one degree than at three degrees, but 1700 revs had to be obtained ten seconds before a smooth takeoff was attained.”

The last entry appearing in the log is March 2, 1939 – “experiments at 1700 rpm.” A total flying time of 4 hours and 5 minutes had been accumulated. With financial support not available and a war appearing on the horizon, further tests were suspended.

In a letter dated December 2, 1957, the National Research Council of Canada expressed an interest in any information available on the helicopter, its construction, operation, and results of any experimental flights. The reply from Nicholas Froebe was a modest one with no major claims of success, mainly due to the excessive vibration problems that haunted them, although the machine exhibited sufficient control as far as the tests conducted were concerned.

The helicopter in which these three pioneers conducted their experiments is now part of the collection in the Western Canada Aviation Museum in Winnipeg, Manitoba.

Article courtesy: Paul Dyck, EAA Canadian Council

 
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