Term used by amateur flight "simmers" who typically watch certain disgraceful Youtubers. It is used to describe unrealistically smooth aircraft landings in a flight simulator or even real life, typically under a descent rate of 75
feet per minute.
People who use this term are often frowned upon due to the fact that "butter" is usually used as a way to
flex or appear as a tryhard.
Look at that butter! The aircraft landed so smoothly!
Did you see that Airbus A330 butter? I
bet the passengers
never knew when they actually landed.
OMG that was such a
smooth butter!