528 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1939 



good assurance of safe landings under all conditions of visibility. 

 At the present time the chief navigational hazards result from 

 conditions requiring blind flying, and from electrical conditions of 

 the atmosphere interfering with radio transmission and reception. 

 Steady improvement is being made in equipment designed to meet 

 these and other conditions affecting safety, and only this past fall 

 four distinct advances in equipment making for safety were an- 

 nounced. These are: 



1. The radio echo altimeter for indicating the absolute distance from the 



ground, instead of the altitude above sea level, as with the standard 

 type of instrument now used. 



2. A new form of static suppressor which it is hoped will go far toward 



eliminating this serious hazard to radio communication between the 

 plane and sources of needed information. 



3. A new form of automatic direction finder for guiding the pilot to a source 



of radio wave with which he is in tune. This device may also be con- 

 nected up with the automatic gyropilot in such way as to provide auto- 

 matic blind flying toward the source of the radio waves. 



4. A device for indicating approach to the dangerous condition known as 



the "stall" — meaning an approach to an angle of attack so great that 

 the plane will pass out of control of the pilot and probably fall into 

 a spin. 



These are all steps forward along the general line of greater safety 

 in air transport. 



Turning for a moment to services on the ground, we find here, 

 perhaps, at the present time, the largest opportunity for improve- 

 ment. In recent years, funds far too small have been made avail- 

 able for improvement in the various agencies which are intended 

 to supply the pilot at all times with reliable information on all 

 matters affecting the safety of his flight. This condition must be 

 corrected and improved ; and with an adequate utilization of all that 

 is now known and available in the science and art of meteorology, 

 radio, and airport equipment, the causes of many casualties in the 

 past would be removed. 



There remain, to be reckoned with, human errors. We can hardly 

 hope that we can ever entirely eliminate this potential hazard to 

 safety. Rigid requirements for license as a transport pilot with retests 

 from time to time have given us a highly trained and highly reliable 

 body of pilots for this service; but there is, and, so far as I can see, 

 there will always remain some residual hazard of human error — a 

 hazard, however, which may be minimized in some degree by the 

 presence always of a copilot ready to assume control in any case where 

 corrective control might save the day. 



Not to delay too long over this matter of safety, I can summarize 

 my own feelings in the matter by saying that I cannot see, in any 

 future within the scope of present vision, a reduction of the margin 



