592 Our Surroundings 



Radio is now used in many ways to make flying safer. The 

 pilots of all big passenger planes are in constant radio communi- 

 cation with the different airports along their routes. At frequent 

 intervals they receive detailed reports about the weather ahead of 

 them, the height of the clouds, the condition of the landing fields, 

 and other important information. They, in turn, keep the airport 

 officials informed concerning their location, their course, and any 

 difficulties which they may be experiencing. 



The latest way in which radio helps aviation is through the 

 use of radio beacons. These are automatic sending sets located 

 at principal airports. By means of a special apparatus, each 

 beacon sends out a continuous series of radio waves which make a 

 steady buzz in the radio receiver of a plane flying directly toward 

 the beacon. If the plane gets off its course and flies to the right 

 of the beacon, the steady buzz breaks up and becomes a series of 



signals, . If the plane flies to the left of the beacon, 



the steady buzz breaks into a different series of signals, 



. Thus the pilot, by listening to the beacon signals 



and changing his course whenever the steady buzz breaks up into 

 either series of signals, can manage to fly steadily toward his des- 

 tination, even when he does not know where he is and is unable 

 to see the ground or any familiar landmark. 



Floodlighting and Searchlights. In the early days of avia- 

 tion, all flying had to be done by daylight. A pilot who was still 

 aloft when darkness fell could not make a safe landing, for he 

 could not see the ground. Now, all that is changed. Passenger 

 planes make regular night trips from city to city, flying as safely 

 as by day. 



While radio plays an important part in making flying safe, 

 the part that light plays is almost as important. A plane 

 approaches an airport after dark. While still miles away, the 

 pilot sees a flash of light far in the distance. Again and again 

 comes the flash, at regular intervals, guiding the plane straight 

 to the field. Then, as the plane circles and prepares to land, sud- 

 denly the entire field is bathed in a brilliant, even light which 

 makes landing as safe as in broad daylight. 



Two kinds of lights are used to make night flying safe 



