212 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1954 



and the landing on skis was simple and effective and short. Then, 

 as their power grew greater and the Model B developed from the 

 original 12-horsepower to the 30-horsepower class and their power 

 loading went down to 40 pounds a horsepower, wheels were feasible 

 and were merely added to the then-existing skids. Then for many 

 years landing gears of airplanes all over the world, with one out- 

 standing exception, were always a combination of wheels and skids, 

 the theory being that if the wheels failed, the skids would save the 

 works. The one outstanding exception was Bleriot in France who 

 never had any use for skids. In those early days we soon discovered 

 that many a landing resulted in an accident, not because the wheels 

 failed, but because the skids broke, dug into the ground, and turned 

 the airplane over. So some of us here proposed and put into effect 

 the simple 2-wheel and tail-skid landing gear which was lirst intro- 

 duced at North Island by the author in 1913 and incorporated with a 

 great saving in weight on several then-existing Army training planes. 

 By placing the wheels reasonably forward, nosing-over tendencies 

 were avoided, skids ceased to break, and this type of landing gear be- 

 came standard for the next 30 years. Then there started to come into 

 wider usage the presently widely used 3-wheel gear with nose wheel 

 forward and the two main wheels aft of the center of gravity. This 

 "level" type is of course very practical and effective and will continue 

 to last for some time. But meanwhile advances continue, and the next 

 step in landing gears is going to be either a catapult track or a dolly 

 truck for takeoff with the airplane equipped only with skids to land 

 on. To be sure, these skids will wear out after many landings, but so 

 do tires. By doing away with the wheel and the tire we not only 

 shorten the landing, but we do away with complicated braking sys- 

 tems and with the heavy weight of wheels and, what is even more 

 serious, the difficulty of stowing wheels in the thin wings that our 

 higher-speed regimes now demand. Of course there is another ad- 

 vantage — the ski landing gear can take off from water, can land 

 on snow, can land on mud, and if we finally do get to vertical-take- 

 off aircraft, as we are very likely to soon and in great quantities, the 

 wheel gear will disappear except for small rollers for convenience in 

 handling on the ground. And thus we will get back to the ski-equipped 

 airplane that the Wrights started with 50 years ago. 



During the landing-gear development of this era, it is surprising to 

 note how tardy and stubborn and backward most aircraft constructors 

 were in adopting retractible landing-gear configurations to improve 

 their performance. It is safe to say that had it not been for the de- 

 velopment of the amphibian, which showed the ease with which land- 

 ing gears could be retracted, the progi'ess in this area would have been 

 even slower. 



