5. SPECIAL CLOUD TRACKING (WILSON) FLIGETS:

.

a The first of these flights, Wilson 2, wes directed
by Rad Safe to pre-planned post=-shot seerch. This requireé tse
aircraft to remain in a holding pettern track apprcozizcately 50

miles West of Ground Zero from plus two to plus five hours.
This portion of the track was designed for the purpose of dee
tecting radioactive cloud movements toward Eriwetok gtoll. oo

BRAVO the maximum activity encountered wes less then 15 cr/hr.

Through a misunderstanding of control procedures, wilson 2 ovesstayed in the holding pattern. When Rad Safe realized this fect,
CIC was requested to order him into the previously designeted
search sector at once. The delay, however, resulted in tris aire
craft being well behind and to the North of the cloud seszects
thet must have caused fallout on Rongerik and Rongelap. gt 155m)
the aircraft reported its maxirurm reading during this fligts. cls

wes reported as being between 500 and 1000 ar/br approximately

150 nautical miles from Ground Zero at a bearing of 60 desrees.

This and the subsequent deta appeared to verify the forecast cloud

trejectories which indicated the upper cloud segments would leave
the PPG on an approximate bearing of 70 degrees, thus avoiding
the populated atolls. Wilson 2 subsequently reported iz-flight
difficulty with the instruments used.
be On the
the second tracker,
general area but to
cloud movement. st

besis of the results of the Wilson 2 flight
Wilson 3, wes instructed to search the sase
proceed further East to define the rate of
approximetely 2000M information was recetved

indicating the possibility of some contamination in the Rongerik/

Rongelap area.

4 message was immediately dispatched to Tg Fh

requesting Wilson 3 to alter his search area in such a manné> as
to cover ths populated area to the East. Communication delays

prevented Wilson 3 from complying with the request. This plus
the fact that no exact instrument readings (instead a range of
readings) were reported made interpretation of cloud tracking

data difficult.

Ce Subsequent Tilson flights ( for plus one day} were
cancelled when it appeared that no sir contamination protier ert-

isted at that tim.
6.

7

af

/

WEATHE RECONNAISSANCE FLIGHTS:

Two Petrel Juliet veether reconnaissence Tligits were

flown on plus one dey.

‘These flights were flowto toe Sosth ang

to the SoUtheast and indiceteé essentially zero air conta=-cét.cse

2

are

Select target paragraph3