The Butler Blackhawk and the Skyway from which it was developed were American three-seat open-cockpit single engine biplanes of the late 1920s that were built in small numbers immediately prior to having their intended production run interrupted by the onset of the Great Depression.
Design and development
The fuselage was built from chromium-molybdenum alloy steel tubing faired to shape with light wooden battens and covered in dopedaircraft linen.[3][4] Separate cockpits were provided for the pilot, in the rear, with the two passengers up front, with a baggage compartment behind the pilot.[5] Unusually, the pilot was provided with dual engine controls, one on each side of the cockpit.[3] Like the fuselage, the empennage was built up from welded chromium-molybdenum alloy steel and covered in fabric with the elevators being adjustable in flight from the cockpit.[5][4]
The biplane wings were built up around two solid spruce spars with built-up plywood ribs forming the airfoil section.[5] No center section was used, as the wing panels were joined along the centerline. While the main fuel tank was in the fuselage, it was supplemented with smaller gravity tanks in each upper wing root.[5]Frise-type ailerons actuated by push-pull tubes[4] were fitted to the lower wings only.[5]
It was fitted with a split-axle undercarriage.[5]
Variants
All variants were powered by a single 220 hp (160 kW) Wright J-5 Whirlwind air-cooled radial engine,[2] although the prototype was initially reported as having a 200 hp (150 kW) J-5.[4]
Main variant, 11 built, including one converted from Skyway.[2]
Leuthart D
Single Blackhawk (msn 112, NC14422) renamed by purchaser.[2]
Operational history
Butler Manufacturing were producers of pre-fabricated steel buildings, including aircraft hangars who decided to expand into aircraft construction, however shortly after they begin production, the 1929 Stock Market Crash and the onset of the Great Depression began to severe impacted their profitability, both with their main line of business, and with regards to aviation and they almost immediately shut down their production line to preserve their core business. As a result, only 13 serial numbers were allocated.
Hoot Gibson, a famous 1920s and 1930s cowboyactor, bought Blackhawk[3] NC730K serial 105,[6] however, it was while flying a similar Swallow biplane borrowed from a friend that he crashed at the National Air Races in Los Angeles on 3 July 1933, and not the Blackhawk.[7]
Some examples began being used as crop dusters at the end of the 1930s.[3]
Msn 110 N593H is currently registered and airworthy by a private owner with the FAA in Rockton, Illinois,[10] and as last seen was painted black with yellow wings at the Kelch Aviation Museum in Brodhead, Wisconsin.[11]
Msn 111 NX299N is currently on display at the Science City at Union Station, suspended over the atrium and painted orange with cream wings and control surfaces.
Specifications (Butler Blackhawk (ATC 135) )
Data fromU.S. Civil Aircraft Vol. 2 (ATC 101 - 200)[3]
^Number includes the second prototype Skyway, which was destroyed without having been registered, and the sole cabin variant.
^Minimum, based on fuel burn rate of 11.5 US gal (44 L; 9.6 imp gal)/hour at the 110 mph (180 km/h) cruise speed and a weight of 6.02 lb/US gal (0.721 kg/L) for aviation gasoline, such as for 100LL and 80/87 fuels