Smithsonian Report, 1959—Loening PLATE 2 
@ 
LANDING GEARS 
1, Martin-TT, tractor training plane, 1915, showing cumbersome landing gear with 
extra wheels and skids; 2, Curtiss JN4 (“Jenny”) training plane, 1918, showing 
simple 2-wheel landing gear which later came into world-wide use; 3, Douglas 
DC-7B of 1955, showing classical gear-level aircraft position used widely on modern 
air transport planes. 
