The phrase “souls on board” derives from nautical usage. In radio comms, being brief and direct are critical. ATC requests how many living people (or not known

The phrase “souls on board” derives from nautical usage. In radio comms, being brief and direct are critical. ATC requests how many living people (or not known to be dead people) are aboard in order to relay the number to search-and-rescue. Being monosyllabic, its use in “aviationese” is a matter of economy of expression and not a political statement or invitation for handwringing. It also sidesteps potential fussy categorization along the lines of, “We have two crew and one passenger.” In comparison with the above nine syllables, the relevant information requires two: “Tree souls.”