The Fokker K.I (for ''Kampfflugzeug''/"combat aircraft"), also known as the M.9, was a German experimental aircraft.
First flown in 1915, the M.9 had two
M.7 fuselages and tails, without engines, mounted on the lower wing. To this was added a central nacelle with two seven-cylinder 80 hp
Oberursel
Oberursel (Taunus) () is a town in Germany and part of the Frankfurt Rhein-Main urban area. It is located to the north west of Frankfurt, in the Hochtaunuskreis county. It is the 13th largest town in Hesse. In 2011, the town hosted the 51st He ...
U.0
rotary engine
The rotary engine is an early type of internal combustion engine, usually designed with an odd number of cylinders per row in a radial configuration. The engine's crankshaft remained stationary in operation, while the entire crankcase and its ...
s, one at either end, in a
centerline thrust
An aircraft constructed with a push-pull configuration has a combination of forward-mounted tractor (pull) propellers, and backward-mounted ( pusher) propellers.
Historical
The earliest known examples of "push-pull" engined-layout aircraft inc ...
configuration. The crew of three included a pilot in the nacelle, and one gunner positioned at the nose of each fuselage.
Mounting the two fuselages on the wings with no connection between them further aft turned out to be a mistake. Fokker was still using wing warping instead of ailerons for roll control, so when the wings were warped, the fuselages were deflected in opposite directions, either up or down depending upon which way the aircraft was rolled. This led to some very divergent flight characteristics. The test program was brief.
1910s German attack aircraft
K.I
Aircraft first flown in 1915
Rotary-engined aircraft
Twin-fuselage aircraft
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