A rare colour photograph of one of the three Sabena-Congo S-55As. The trio essentially adopted the same colour scheme as the S-55s used by the airline in Belgium, but with the latter’s blue stripe replaced with a green stripe instead.

Sikorsky S-55A OO-CWG (c/n 55-840) passes overhead trailing a plume of insecticide from its modified exhaust pipe. The long extension was attached to the side of the helicopter’s port side and is clearly visible here. The insecticide was fed into the pipe by means of a hose attached to a tank fitted in the S-55A’s main cabin.

The same machine spraying insecticide over Leopoldville in November 1961, by which time it was being used by the World Health Organization as “WHO1”, the markings of which are just visible on the ventral fin aft of the cabin. The other two S-55As used by Sabena-Congo were both written off, OO-CWE in 1958 and ’CWF in 1960.

The wreck of S-55A OO-CWF (c/n 55-839) being dismantled after it suffered a structural failure on the ground near Inga Falls on the Congo River in the west of the country. Among the wreckage in the foreground is the insecticide tank with its feeder hose still attached.

With what might today be deemed shocking disregard for the population on the street below, WS-51 Dragonfly OO-CWC deposits insecticide over an urban neighbourhood in the early 1950s.

"Hold your noses, boys!” A military camp near N’Dolo Airport in Leopoldville gets a comprehensive dusting by one of the Dragonflies.