I heard this line in Top Gun (1986) film:
Airboss: Ready Willard and Simkin off CATs three and four.
What does "CATs three and four" mean?
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Sign up to join this communityCATs three and four refer to an aircraft carrier's Catapults (number 3 and 4 in your question) used for launching/catapulting aircraft off the flight deck (in addition to the aircraft's own engine thrust/power).
Like the other poster suggested, ‘CAT’ being short for aircraft catapult. This is a reference to catapults number three and four, sometimes called the ‘waist’ catapults or waist cats marked in red below.