Model Expo Model Airways Sopwith Camel Clerget Rotary Engine 1:16 Scale Model Kit MA1031

WORLD WAR I Rotary Aircraft Engine HISTORY Developed by Clerget and manufactured in France, the Clerget 9B was an improvement over the company's seven cylinder, 80 hp rotary engine. In versions of 110 to 140 hp, these models saw widespread use throughout the first world war in the F.1 Camel, Triplane and Baby by Sopwith, and in the Nieuport 12. The model 9B was rated at 130 hp in normal use but could be pushed to 135 in an emergency at 1,250 rpm. Maximum weight was 380 pounds. Although a counter-intuitive design by today’s standards, fixing the propeller to a spinning engine on a stationary crankshaft simplified cooling, had an excellent weight to horsepower ratio and allowed greater flexibility in locating the aircraft’s center of gravity – affecting maneuverability -- over the in-line engines of the time. One drawback, however, was the pronounced gyroscopic effect that pulled the aircraft to the right. To fly in a straight line, pilots had to compensate for this by applying constant left rudder. The Clerget rotaries provided improved speed control over the Gnome and Le Rhone rotaries by replacing the standard “blip” switch that temporarily grounded the magneto (killing the ignition) with a selector switch that restricted the engine to run on 9, 7, 5 or even 3 cylinders. Like the earlier rotaries, the Clerget spewed unburned castor-oil from the exhaust, adding to the pilot’s discomfort. Pilots were issued a small bottle of blackberry brandy to counteract the smoke’s laxative effect. Instructions and prototype by Kenneth H. Goldman