sliif'l of slii|)piiig tracks on schedule and jiiade it unnecessary to 

 establish a surface patrol. 



AERIAL ICE OBSERVATION 



Fifty-two ice observation flights were made during the period from 

 23 February to 28 June 1961. These flights averaged approximately 

 1,150 miles in length and 7.1 hours duration. Each flight was planned 

 for maxinnnn coverage in a selected area consistent with a determi- 

 nation of tlie Ihnits of all ice and the limits of sea ice of five-tenths 

 concentration. The elements considered in selecting the search area 

 consist of the following: (a) Degree and reliability of available ice 

 information over the Grand Banks, (b) prevailing conditions of wind, 

 sea, visibility, and sea and air temperature, and (c) the activity of 

 the Labrador Current. At all times it was necessary to keep in mind 

 the primary objective specified in Safety of Life at Sea Convention. 

 This objective is to maintain accurate information concerning the 

 southwestern, southern and southeastern limits of all ice in the vicinity 

 of the Grand Banks of Newfoundland. As much information as 

 possible concerning the location and character of ice within the limits 

 was obtained consistent with accomplishment of the primary objective. 



Eight preseason observation flights were made from 13 January to 

 23 Febi'uarv by Air Detachment aircraft to establisli tlie southern 

 limits of the ice in its southward drift. The information developed by 

 these flights was the major factor in (kUermining the time that the 

 patrol forces should be assembled and services commenced. 



Durmg the period from 28 June to 1 November, 12 regular post- 

 season reconnaissance flights were made to guard against an undetected 

 ice encroachment. Three special flights were nuide (hn-ing late October 

 to track one iceberg drifting south of the 48th parallel of latitude. 



COMMUNICATIONS 



i^ijnary radio communications foi- international Ice Patrol was 

 conducted h\- L.S. Coast Guard Kadio Station (XIK), Argentia, 

 Newfoundland. Ice advisory bulletuis to shipping were broadcast 



