times. By 3 May it became necessary to discontinue the use of 

 tJie Mojave as an experimental vessel. Nevertheless, a continuous 

 surface vessel patrol of the critical area was maintained through- 

 out the season. The shortage of trained personnel and special 

 equipment prevented the resumption in 1946 of a full scale oceano- 

 graphic program such as was carried out prior to the war. This 

 was unfortunate in view of the unusual current patterns that were 

 indicated by berg drifts and the distribution of sea surface tem- 

 peratures. Similar problems made it impracticable to attempt the 

 resumption of the 3-year series of post-season cruises for the pur- 

 pose of the annually repeated iceberg census of Baffin Bay^ begun 

 in 1940 and discontinued the following year because of the lack of 

 available vessels. 



AERIAL ICE RECONNAISSANCE 



As aerial ice observation flights have not previously been under- 

 taken in connection with International Ice Patrol a brief sum- 

 mary of such operations during the 1946 season is given here. 

 United States Coast Guard PBY-5A planes, popularly known as 

 Catalinas, were used occasionally throughout the season. After 

 24 February two PB4Y-1 aircraft were available and most of the 

 aerial ice scouting was done in these planes, popularly known as 

 Liberators. At the end of the season one of the PB4Y-1 aircraft 

 was replaced by a PBIG (Flying Fortress) and the final flight of 

 the season was made in it. The first flight of the season took place 

 on 6 February and the last flight occurred on 1 August. A total 

 of 71 flights were made on 44 diff'erent days for a total of 550.2 

 plane hours distributed as follows: 



Plane hours 



February .- - 25.2 



March - - - — - 133.7 



April 95.1 



May _. -.._ _ 100.9 



June -- _ — --— — — 110.7 



July -- _ _.- 78.4 



August 6.2 



The individual flights varied in duration from 2.1 to 12.5 hours 

 with an average of 7.7 hours although the most frequent duration 

 was between 8 and 10 hours. On only one occasion was it neces- 

 sary to land at an alternate field. Flights were made whenever 

 prospective terminal conditions, flying weather, and observing 

 weather in the critical area combined to give promise of a suc- 

 cessful aerial reconnaissance. Following this policy resulted in 

 the following intervals between days on which flights were made : 

 one interval of 15 days; one of 11 days; three of 10 days; one each 



> See Smith, Edward H. Ice Observation In the Greenland Sector, 1940. International Ice 

 Observation and Ice Patrol Service in the North Atlantic Ocean — Season of 1940. U. S. Coast 

 Guard Bulletin No. 30, p. 13 (1941) Washingrton. 



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