< arrey intro

 

The UFO Sighting at Arrey

 

Charles B Moore and his crew launched a "pibal" - a neoprene rubber "pilot balloon" - which would be observed through a 25-power David White ML-47 theodolite. Pibals were typically launched before large balloon flights to help predict the path the bigger balloon would follow.

See: Pilot Balloons: A 1944 US Navy manual on the process of launching and tracking weather balloons

Pibals being launched by Skyhook crew (USAF)

Below, diagrams show details of typical theodolite of the period: