B4-2 RELEASE AND RECORDER RECORD 
message may be substituted for the log provided such copy is retained in 
the station files for one year. Regardless of the method used in filing 
the NOTAM, it will also be transmitted on available local interphone and 
teletypewriter circuits. 
2.2 (WB) Release At or Near Controlled Airports. To reduce the pos- 
sibility of the radiosonde, train, and balloon becoming a hazard to air- 
craft in flight, observers will inform the localcontrol tower thirty min- 
utes before the intended release. Arrangements will be made to obtain 
clearance from control tower personnel, by telephone or visual signal 
at the time of actual release. 
2.3 (WB) Release at Non-Controlled Airports. Raob stations at air- 
ports not having an operative control tower willrelease the balloon after 
a visual survey indicates that the flight train will not present a hazard 
to aircraft operating in the vicinity of the airport. 
2.4 (AF, N) Release at Military Establishments. The local communi- 
cations commander will be advised of the schedule of observations cur- 
rently in effect at the rawinsonde section, and the necessary arrange- 
ments will be made to obtain clearance from the tower by telephone or 
visual signal for each rawinsonde or rawin release. The procedures to 
be used in obtaining the clearance for release will be made a matter of 
record and filed in the permanent files of the rawinsonde section. 
3. The Release. Release procedures must necessarily be varied with 
wind conditions at the site from which the release is made. The observer 
should be familiar with all obstructions around the area before attempt- 
ing a release. Before the balloon is removed from the inflation shelter, 
the wind direction and speed will be determined and a point selected 
from which the radiosonde may be released without striking obstructions 
or encountering downdrafts. 
3.1 Release Precautions. A continuing source of danger to personnel 
is associated with radiosondes which become entangled with high tension 
power lines and transmitting antennas. When entanglement occurs, it is 
usually at release - especially during periods of high wind and heavy pre- 
cipitation. No attempt should be made to disentangle radiosondes, but the 
circumstances should be reported at once to the officials of the power 
company, broadcasting station, or communications agency involved. 
3.2 Posting of the Location of All High- Tension Wires and Transmit- 
ting Antennas. The location of all high-tension wires and transmitting 
antennas in the vicinity of all of the points of release at the station will 
be charted by the official in charge, and posted in a conspicuous place 
= =O FMH#3 
