Michael Gregor was born in Russia in 1888. He was educated there and became Chief Engineer of the First Russian Aircraft Corporation in 1914 and then was a consulting engineer with Miltzer Aircraft Division at St. Petersburg from 1915 to 1918. He went to the USA in 1921 and served with several firms before joining Bird Aircraft in 1927 where he became Chief Engineer. Before joining CCF he worked for Seversky Aircraft Corporation.
Gregor was well aware of the new family of fast low-wing monoplane fighters which was then appearing, but he believed that with careful design the biplane could develop a good speed and its compactness should ensure a high degree of maneuverability. The aircraft he designed was designated FDB-1, indicating its intended role as a fighter dive-bomber, but it has been popularly known as the Gregor Fighter in deference to its designer.
Its stubby fuselage was of stressed-skin construction and the landing gear wheels folded pneumatically, quickly and neatly, into its sides forward of the wing. This avoided the usual hump on the lower fuselage as seen on Grumman aircraft but necessitated a pylon on the underside of the fuselage as a pivot point. The unequal-span wings were of duralumin construction and fabric covered.
The upper wing was of gull form to avoid obstructing the forward vision and to make a clean junction with the fuselage. Flaps were fitted along the length of the trailing edge of the lower wing and inboard of the ailerons on the upper wing. Automatic slots were provided along the leading edge of the upper wing. The fixed tail surfaces were of stressed-skin construction while the control surfaces were fabric covered metal structures.
The power plant of the prototype was a Pratt & Whitney R-1535-SB4-G Twin Wasp Junior rated at 750 hp at 9,500 ft (2,895 m). The airframe was stressed to take radial engines of up to 1,200 hp. It was estimated that it would have a maximum speed of 300 mph (482.7 kmh) and 362 mph (585.7 kmh) respectively with the 750 and 1,200 hp engines, but RCAF tests indicated that the first estimate was optimistic so it seems probable that the second was also. Armament was two 0.50 in (12.7 mm) guns mounted in the upper wing roots and provided with 1,000 rounds of ammunition. Two 116 lb (52.7 kg) bombs could be installed under the lower wing outside of the slipstream.
The prototype completed a trail assembly on October 31, 1938 and on December 17, 1938 (site files) it was first flown by George F.G. Adye from Bishopsfield, Fort William. By May 1939 it was at St. Hubert Airport, Montreal, Quebec and began its CofA tests there on May 10. The tests included full aerobatics and terminal velocity dives. The coupé top was found weak during aerobatics and it was recommended that aerobatics be restricted until it was strengthened; the maximum speed was down from the estimate.
Flight Lieutenant Lawrence E. Wray, who conducted the tests, noted that "as a prototype, the Gregor aircraft is a most successful effort" and also that "Below 15,000 ft (4,572 m) a contemporary low-wing monoplane type of interceptor or single-seater, despite superior performance, could not successfully engage the Gregor singly". Nevertheless there were deficiencies, besides the coupé top. The flight controls were too sensitive and should be corrected and the flap area or angles should be reduced. It was also observed that the visibility from the machine was poor both on the ground and during take off.
In January 1940 the FBD-1 was entered in the American MacFadden Race from New York, New York to Miami, Florida, but was forced out at the start because of falling oil pressure. On March 3, 1940, the landing gear collapsed while the aircraft was being taken out for a test flight at St. Hubert by George Adye and on the 31st it overturned in deep snow at. St. Hubert with only slight damage to the aircraft and no injuries to Adye.
By May it had been decided to transfer the FBD-1 to Mexico and the Mexican civil registration XB-ABY had been granted and painted on. The machine was to be flown to Mexico by Howard F. Klein, but the Department of National Defence would not grant an export permit so the machine was placed in storage. It was burnt on the ground in 1945.