The primary spray aircraft, all delivered in the late 1980s and early 1990s, feature upgraded electrical connections,
paratroop doors with a sealable port that accommodates the four-inch diameter pipe for the spray nozzles, and
internal plumbing for an inner and outer set of spray bars mounted under each wing. “The spray bars give us extra
coverage per pass, but they are not used on most missions,” notes Townsend. “We mainly use the door nozzles.” The
nozzles and spray bars are installed on the aircraft after arrival at a deployed location.