During the 1948 season two winterized PBIG (Flying Fortress) planes 

 were used for aerial ice reconnaissance. A total of 84 flights were made 

 on 64 different days from 6 February to 6 July, inclusive. The duration 

 of these flights totaled 637.4 hours distributed chronologically as shown 

 in figure 1. 



200 



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5 ^ -i 



(D K K >. z G 



UJ < Q- < 3 3 



U. Z < 2 => =^ 



DISTRIBUTION OF PLANE HOURS » 1948 



FiGUKE 1. — Distribution of plane hours, 1948. 



The individual flights varied in duration from 1.5 hours to 11.6 hours. 

 The flights averaged 7.6 hours per flight. The maximum interval be- 

 tween flights was 21 days occurring between 17 May and 7 June. The 

 remaining intervals between flights are summarized below: 



Interval in days: Frequency 



1 26 



2 19 



3 8 



4 5 



5 3 



6 1 



4 



