AIR TRANSPORT — DURAND 527 



Structurally, the element of hazard here should be brought close 

 to a point comparable with that in the main airplane structure. In 

 the matter of operation, as long as we employ a type of fuel involving 

 carburetion and electric ignition, it now seems difficult to see how all 

 hazard of interruption is to be avoided. However, an answer here is 

 found in multiple power units. At the present time the accepted 

 standard in large air transport structures is four independent power 

 units, any two of which should insure adequate power for the safe 

 handling of the plane, at least to the nearest landing field. It seems 

 hardly within the limits of probability that two power units would 

 fall into trouble at the same time, and thus, with four such units, of 

 which three or in any event two, would always be available, we 

 should have assurance of adequate power for safety under any condi- 

 tions which can be foreseen. 



Hazards resulting from carburetion, ignition, and the danger of 

 fire following a crash, could be minimized by the use of the Diesel- 

 type engine with fuels of the so-called safety type. At present, 

 however, this would involve some sacrifice either of performance or 

 of pay load and seemingly in our present temper we are slow to 

 forego the service which present conditions give us, in exchange for 

 this added margin of safety. 



With regard to navigational equipment, there is no excuse for 

 any lack of the best of such equipment now available, and certainly 

 on all major lines of transport, there is no such lack. It is obvious 

 that at all times the pilot must have the means of knowing his 

 speed, his altitude, the direction in which he is flying and whether 

 in a straight or curved path. He must also know where he is, as 

 nearly as possible, and hence the distances and directions of nearby 

 landing fields. He must also be able to ask for and receive informa- 

 tion by radio on any and all matters affecting his flight. 



Normal instrumental equipment with adequate services from the 

 ground will give him all this, except as weather conditions (fog, 

 snow, electrical disturbances, etc.) may interfere. 



There is room here, however, for improvement, for which we may 

 look with confidence in a near future. One of the most important 

 of these problems is that of bringing a pilot from altitude, under 

 blind flying conditions, to a safe landing on the field beneath him. 

 It is relatively easy to guide a pilot to a point in the air over an 

 airport. It is less easy to guide him down, blind, to a safe landing. 



Very definite progress has been made toward the solution of 

 this problem, and quite recently a most noteworthy advance has been 

 reported — a new form of radio beam for blind landings — bringing 

 the plane safely to the landing field in fog or thick weather. I must 

 not take the time for detail, but this promises to be an outstanding 

 advance over all previous methods for blind landings, and to give 



