Why are people on planes or ships referred to as souls?

Looking back, the Word "soul" may have its origin from the Greek Word psyche. As the Word was used further north and west in Europe, those different cultures, who were by and large sea-faring cultures themselves, developed their own Words to indicate the same meaning as psyche (which means life, spirit, consciousness).

The concept is that a "soul" is something that is alive or has a living spirit, so when a distress call goes out and the number of men, women, and children are given, they're often given as "souls" (the living) rather than men, women, and children which may take more time to transmit.

There is a cultural variance on who references people on planes or ships as souls, but those who are in planes normally utilize some the same basic terminology as ships when referencing navigation.