Sure, Bin Laden is dead, but there are still some things (a lot of things) you definitely can’t do at the airport. Running onto the tarmac is one of them, but that’s exactly what Andre Reid did on Wednesday afternoon at LaGuardia. At around 1 p.m., a pilot spotted the deranged Reid walking around “like he was taking a stroll in his backyard.” No one’s exactly sure how he got there, but everyone agrees it was a very bad idea. “That in itself is very scary — that he was able to get within feet of an airplane that was due to take off,” said one airport official. The pilot who spotted Reid was so spooked by the incident that he opted to “dump” the flight, which means that all passengers and luggage had to be re-screened, delaying the flight for more than an hour. LaGuardia officials are still trying to figure out how Reid — who was charged with trespass — actually made it out to the tarmac without anybody stopping him.