Learn Italian: Il personale, ossia l'equipaggio, prepara l'atterraggio. - The personnel, that is to say the crew, is preparing the landing.

Ossia means "that is to say" or "in other words." It is used to clarify or provide a more precise word for what was just said. You can absolutely use cioè here; they are highly interchangeable in this context, though ossia can sometimes sound slightly more formal or precise.

Why use both personale and equipaggio in this sentence?

Personale is a general word for staff or personnel, which could refer to anyone working for the airline or airport. The speaker uses ossia to narrow it down and specify the equipaggio, which refers exclusively to the actual crew on board the aircraft.

The English translation says "is preparing", but prepara is the simple present tense. Why not use the present continuous here?

In Italian, the simple present tense like prepara is frequently used to express actions happening right now. While you could use the continuous form sta preparando to really emphasize the ongoing action, the simple present is completely natural and very common for this exact situation in Italian.

How is the word atterraggio formed?

It is built around the noun terra, which means ground or earth. By adding the prefix a- and the suffix -aggio (which often forms nouns out of actions), it describes the action of going to the ground, meaning the landing.