PAX: What is the origin of the term in aviation?

The origin of the term "pax" in commercial transport, particularly aviation, dates back to the mid-20th century. The term, commonly used to count people on board, is an abbreviation derived from "passenger."

In German, "PAX" is often interpreted as "Persons approximately," as seen in documents from the European Union and the Committee of the Regions.

English.SE discussions highlight the debate over whether "pax" stands for "Passengers and Passes." However, historical references, such as a 1946 issue of Air Facts: The Magazine for Pilots, reveal that the traffic department labeled passengers as "pax," while flight crews colloquially referred to them as "bodies."

The use of the '-x' suffix in "pax" is a characteristic of aviation terminology, representing an abbreviated contraction. This convention extends beyond aviation, with examples like WX for weather, MX for maintenance, CX for cancel, TX for transmit, and RX for receive.

Despite assumptions that "pax" derives from "passenger," the possibility of it originating from the merchant navy is also considered. The 'x' as an abbreviation marker is not exclusive to aviation and is found in various domains, including medical abbreviations like Dx for diagnosis and Hx for history.

It's noteworthy that "pass" isn't favored due to potential confusion with the verb and historical usage in employee travel on a 'pass.'

As a side note, the plural "PAX" is commonly used, while the singular "PAP" is remembered in phrases like 1PAP and 3PAX. This plural-singular distinction adds an interesting nuance to the terminology.