itinerary should include both the 85th and 95th meridian. be raft should be Survey Flight per Shots Two dispate to either the §5th or 954¢f meridian, dependh the arrival of the ing on suitability, to coincide cloud. The ction of this fight should be exploratory for the moSt.part. The/“Aircraft should travel well Init beyond the estimated _posifion of the cloud to locate extreme lateral shear ditions. If the location of ith some confidence, the remainder of the fligitit sho be devoted to further cloud delineati crossing at different altitudes. and samples yield no definitive. the traverse sho stantial} to“he northern border of Ce Subsequent Flights: U.S. On the reviously Additional flights made to survey Thesamecloudwill be governed by information derived from the first. The most informative flight pattern would consist of repetitive cloud crossings at varying altitudes so that vertical and horizontal gradients can be measured. 36 Observer's Duties: Each aircraft will be equipped with 1) two 1,000 c.fom. air samplers and a 2610A Survey Meter, 2) conductivity meter, 3) Scintillometer and });) a Cascade Impactor. The observer will be responsible for the operation of this equipment and maintaining a log of instrument readings. ' Entries of the following items versus time shouldbe made on the log sheets provided: scintillometer reading, conduc-= tivity reading, filter paper sample readings, operation of Cascade Impactor and aircraft altitude and position. It may prove unfeasible to complete all entries during the flight. It such is the case, items such as conductivity readings and aircraft altitude and position should be en- tered from the aircraft log after landing. One observer on each flight will be designated in charge. The second observer will relay pertinent data to him by | radio. The observer in charge will determine by his own and the second observer's data what flight pattern to recommend, The conductivity meter will serve as an indication of the presence of radioactivity. When available, entries of aircraft position should be made on the recording chart. The scintillometer is expected to present a more reliable measurement of radioactivity. Readings should be recorded at frequent intervals, particularly w| hen in or near the Y DUN AncruY oo 5 oe are