'upon arrival' is a correct and usable phrase in written English. You can use it to refer to something that happens when a person or thing arrives at a place. For example: "We will discuss the details of the project upon arrival.".
Upon arrival, things looked iffy.
Upon Arrival Pace yourself.
Upon arrival I asked for an upgrade.
Justin Bieber caused a stir upon arrival.
Upon arrival I was hungry.
Upon arrival, they are amused.
Register at the American embassy upon arrival.
Since I tried Ludwig back in 2017, I have been constantly using it in both editing and translation. Ever since, I suggest it to my translators at ProSciEditing.
Justyna Jupowicz-Kozak
CEO of Professional Science Editing for Scientists @ prosciediting.com