ALDA is the four-letter acronym for the character ALAN in the 2011 movie Tower Heist. ALAN is a security guard at the Tower, a luxury apartment building in New York City. He is played by actor ALAN ALDA, who is best known for his role as Hawkeye Pierce in the television series M*A*S*H. ALAN is a loyal employee of the Tower and helps the main characters in their mission to steal back the money that was stolen from them by a Wall Street tycoon.