Ma}' 1952 marked the only mishap occurring 

 at Ice Patrol. A PB1G. making a landing at 

 Goose Bay, Labrador, had one landing wheel 

 collapse, damaging the underbody of the plane. 

 Fortunately, there were no injuries. Rather than 

 undertake repairs at a base so remote, parts and 

 engine were salvaged and the airframe was 

 abandoned. 



For the first time in writing, in Bulletin Xo. 40 

 INTERNATIONAL ICE OBSERVATION 

 AND ICE PATROL SERVICE IN THE 

 NORTH ATLANTIC OCEAN— Season of 1954, 

 aerial ice surveillance is deemed to be efficient. 

 This can be viewed as a prelude to the final ac- 

 ceptance of aircraft as the primary mode of ice 

 observation, reducing the surface vessel to a 

 supplement. 



In 1954, unsuccessful tests were conducted with 

 a bolometer (forerunner of the airborne radiation 

 thermometer) for the purpose of distinguishing 

 between berg and non-berg radar targets under 

 conditions of poor visibility. It had been hoped 

 to identify objects by measuring changes in the 

 radiant heat. 



In 1960, the Ice Patrol yearly bulletin title was 

 changed from "INTERNATIONAL ICE OB- 

 SERVATION AND ICE PATROL SERVICE 

 IN THE NORTH ATLANTIC OCEAN: to 

 "REPORT OF THE INTERNATIONAL ICE 

 PATROL SERVICE IN THE NORTH AT- 

 LANTIC OCEAN". As was stated in the bulle- 

 tin for the Season of 1960. the former title 

 reflected a distinction made when the patrol was 

 conducted by ships alone. The term "ICE OB- 

 SERVATION" was used during a search for ice 

 information; "ICE PATROL" meant that ice 

 information was available and being broadcast. 

 The advent of aircraft reconnaissance and remote 

 sensors, and the integrated activities of the plane, 

 oceanographic vessel and patrol vessel now pro- 

 vided the continuity of information which per- 

 mitted the unqualified use of the term 

 "PATROL". In this bulletin, it is stated that 

 aircraft are the tools of Ice Patrol, to be supple- 

 mented by surface vessels when conditions dictate. 



The HERCULES was equipped with the 

 Doppler Navigation System for the 1963 Season. 

 The readout presentations provided the ice ob- 

 server continuous track and cross track informa- 

 tion, greatly increasing the accuracy of iceberg 

 positions. Maneuvers off the prescribed track. 



once extremely difficult to plot, could now be 

 readily charted. 



Also during this season, an Airborne Radiation 

 Thermometer (ART) was tested. Although the 

 actual water temperatures recorded were consid- 

 ered not sufficiently reliable, the instrument was 

 useful in detecting changes in surface water tem- 

 perature, and therefore provided some help in 

 locating the Labrador Current and its branches. 



Bulletin No. 50, Season of 1964 states ". . . and 

 the aircraft has become recognized as the primary 

 tool for guarding the ice limits and for ice obser- 

 vation." This bulletin also states "Since 1949, 

 the International Ice Patrol has recognized air- 

 craft as the primary means for observing ice 

 conditions and for guarding the limits of icebergs 

 in the vicinity of the Grand Banks.' 



The 1966 Ice Patrol Season, besides being the. 

 lightest and shortest on record (zero bergs south 

 of 48°N and lasting from 1 March to 28 April), 

 marked the third and final year that Commander, 

 International Ice Patrol was permanently sta- 

 tioned at Argentia. In June, the U.S. Coast 

 Guard Air Station Argentia and the Interna- 

 tional Ice Patrol Argentia were disestablished. 

 The International Ice Patrol was transferred to 

 Governors Island, New York. The aircraft were 

 transferred to the U.S. Coast Guard Air Station, 

 Elizabeth City, North Carolina, and would in the 

 future deploy to Argentia when ice conditions 

 warranted. 



A passive microwave radiometer (Model AN/ 

 AAR-33). with the frequency selected for opti- 

 mum ice emissivity, had been installed on one of 

 the Ice Patrol aircraft. A full evaluation could 

 not be conducted this Ice Season due to con- 

 tinuing aerodynamic problems caused by the lo- 

 cation of the microwave antenna dome. 



The radar used in conjunction with the micro- 

 wave radiometer enabled the ice observers to 

 identify radar targets as steel ships or icebergs. 

 Though excellent correlation was obtained with 

 this device, it could not differentiate between 

 wooden fishing vessels and icebergs. Another 

 major shortcoming was the swath width — essen- 

 tially only a narrow band beneath the aircraft 

 could be identified. The aircraft could not fly 

 over every target. The microwave radiometer 

 was used through the 1969 Season. 



In February 1970, the Ice Patrol was notified 

 that the U.S. Naval Station at Argentia would 



49 



