WINGS FOR TRANSPORTATION — WRIGHT 577 



but 1/50,000 as much as 10 years ago. In fact, it is almost exactly the 

 same as for the Pullman car, being, of course, far less than in street- 

 cars and subway trains, and only slightly more than for an automobile 

 traveling at 50 miles an hour. To obtain further improvement will 

 require expenditure of a greater amount of weight, and it is likely that 

 a final stabilizing figure of 65, or possibly slightly less, will maintain. 

 And now for safety (fig. 4 (Z?) ). Here have been shown the actual 

 points for each year which have maintained during the past 10 years 

 for passenger fatalities per one hundred million passenger-miles 

 flown and a trend curve. The record is remarkable and important. 

 Let us take the year 1938, where the figure is five, and let us appre- 

 ciate that this figure represents one fatality for twenty million passen- 

 ger-miles, which is the equivalent of a flight each day from New York 

 to Los Angeles and back the next day, carried on without interrup- 

 tion for 21 years. The record for 1939 is very substantially better (an 

 actual figure of less than I14), so much so that President Roosevelt 

 issued a special news release on this record on November 7, 1939, by 

 which date 500 million passenger-miles of air-transport operations had 

 been completed without a fatality and which, as he dramatically 

 pointed out, was the equivalent of transporting the whole population of 

 the city of Washington to Boston and back. This record has continued 

 unblemished, approaching two-thirds of a billion passenger-miles now, 

 and unstinted credit is due air-line operators for the infinite number 

 of details earnestly carried out which brought about this fine condition. 

 Substantial contributions have also been made by our plane and 

 engine designers in the airplane itself to help make this record pos- 

 sible. A few of these are : The use of multi-engined equipment hav- 

 ing satisfactory flying qualities under all conditions of flight; the 

 general improvement in stability and controllability; the improve- 

 ment in reliability of the power plant; the perfecting of the constant 

 speed propeller; tremendous developments in instrumentation; the 

 use of de-icing equipment; and the current efforts to reduce or elim- 

 inate pilot fatigue by making the pilot's job easier and his working 

 conditions more comfortable. The important advances in the field 

 of meteorology, radio communication, and airway traflBc control 

 should also be stressed. 



AIRPLANE CHARACTERISTICS 



The final curves, figure 5, illustrate trends of airplane character- 

 istics. Cruising speed, in 10 years, has roughly increased from 100 

 to 200 miles an hour — (A). A rather slight flattening-out tendency 

 is now evident although there will be a substantial lapse of time be- 

 fore the limit for certain classes of equipment is reached. In the 

 graph of figure 5 (B) are plotted the trends of wing and power load- 

 ings. Noteworthy is the flattening-out of the wing-loading trend 



