Call Of Duty 4 I Cant?

hey i know theres a mission in cod4 called mile high club but i cant remember compleing the mission i have the game of the year edition and ive completed it and im gong to do it agein do u have to chooose a certen diffucluty to do the mission coz on utube i typed in how to compelete mile high club and they all cae up how t completet milgh high club on vertern