208 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1954 



tion, which almost always brings light weight with it, and finally (4) we seek 

 a low head resistance, obviously, so as to get our best performances. 



No matter what purpose an aeroplane is designed for, be it a large bomber or 

 a small scout, a waste of weight is little short of criminal in aeroplane design, 

 and complication, it is well known, is usually evidence of bad engineering. In 

 fact, the whole essence of really good engineering is simplicity. 



But it took the aircraft industry almost 30 years to learn the above 

 lessons in the configuration of wing structures. And yet such lessons 

 and precepts were exactly what Orville Wright taught. 



ENGINE LOCATION 



Engine location was, of course, another problem of configuration for 

 aircraft designers, which followed prejudices and fashion a good deal 

 more than sound engineering sense should have allowed in these 50 

 years. The pusher installations at the beginning were convenient 

 structurally and supposedly more efficient. In the case of the single- 

 propeller direct-drive installations like Curtiss, this was later to be 

 proved wrong, because the efficiency lost by the added resistance of the 

 faster tractor slipstream on the fuselage was regained by added lift 

 on the wings. This had apparently been appreciated much earlier in 

 Europe than in this country, because in the 1907- to- 1914 era the de- 

 velopment of the tractor fuselage airplane in Europe was far ahead 

 of what we had in this country. It is remarkable that in the case of 

 both Wright and Curtiss we persisted so long in this unsatisfactory 

 pusher type because, of course, of the great danger apparent in many 

 minor accidents resulting in fatalities. The engine often fell out on 

 the crew, owing to the light weight structures that were then needed 

 in order to get into the air at all. Probably one of the reasons for this 

 "pusher" persistence was that for exhibition flying there was great 

 merit in the public's being able to see the aviator completely exposed, 

 sitting on his perch at the leading edge of the wing with no protection 

 from the wind whatever. Even Orville Wright succumbed to the 

 tractor configuration when in 1916 he brought out his INIodel H en- 

 closed-fuselage tractor type, which Howard Kinehart flew around the 

 country so successfully. In seaplanes, the pusher type quickly suc- 

 cumbed because of the spray thrown into the propeller, and the tractor 

 type was even more advantageous there. Then, of course, as we pro- 

 gressed, we got to multimotored aircraft with tlie engines at first 

 mounted between the biplane wings (a most inefficient configuration), 

 and then finally with the engines as we see them today mounted inte- 

 gral on the monoplane wing. It is interesting to note that this effi- 

 cient, correct, and simple type has survived as an element of configura- 

 tion on aircraft for almost 30 years. In this country, of course, the 

 early Boeing 247-D and the Martin bombers of the early 1930's were 

 the eminently successful forerunners of this later-to-become-universal 



