during the period when such reports are requested. This is in the,,^ 

 interest of greater safety to the reporting individual as well as for '' 

 the greater safety of all which results from a better informed iceb 

 patrol. During the 1947 season, 580 different ships made reports k 

 to the Ice Patrol. Of these the nationalities indicated by radio calr, 

 sign were 48.7 per cent United States, 31.0 per cent British,' 4.3 perL 

 cent Swedish, and 3.1 per cent Norwegian; while the remaining 

 12.9 per cent were divided between Netherlands, France, Poland, 

 Panama, Denmark, Belgium, Greece, Spain, Palestine, Eire, Portu- 

 gal, Canada, Italy, Honduras, Liberia, Latvia, and Nicaragua, each 

 of which amounted to less than 3.0 per cent. In 1946 the same first 

 four nationalities amounted to 93.2 per cent of the total of 694 

 ships which reported to NIDK. The decrease in the number of 

 ships reporting in 1947 as compared with 1946 is attributed partly 

 to the smaller number of ships at sea and partly to the shorter 

 period of time during which such reports are requested during a 

 light-ice year such as 1947. 



AERIAL ICE RECONNAISSANCE 



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The use of aircraft in ice reconnaissance again proved to be a 

 very valuable aid in ice-patrol work. One winterized PBIG (flying 

 fortress) plane was available for ice observation throughout the 

 season and a second such plane was available from the latter part 

 of April to the middle of May and again from the end of May to 

 the end of the season. The bulk of aerial reconnaissance was done 

 from these planes and was supplemented by the use of PBY-5A 

 planes within their limitations. A total of 76 flights (62 in PBIG 

 planes and 14 in PBY-5A planes) occurred on 52 different days iCf 

 from 3 February to 22 July, inclusive. The duration of these flights 

 (492.4 hours in PBIG and 92.4 hours in PBY-5A aircraft) totaled 

 584.8 plane hours distributed chronologically as follows : 



February 55.2 



March 91.7 



April 132.9 



May 112.3 



June 115.8 



July 76.9 



The individual flights varied in duration from 2.3 hours to 12.7 

 hours with the PBY-5A flights averaging 6.6 hours, the PBIG 

 flights averaging 7.9 hours and the grand average being 7.7 hours 

 per flight. It was necessary to land at an alternate field on two occa- 

 sions although it is probable that the use of an alternate would 

 have been necessary on a number of additional occasions had it 

 not been for the use of GCA. As in 1946, flights were made when- 

 ever prospective terminal conditions, flying weather, and observing 



weather in the critical area combined to give promise of a success- f' 



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