I actually know somebody that has been to Area 51. He was in the Air Fore, retired now. This happened in the 80s. He was air crew on a C-130 and one of the engines went out. They could still fly but needed to do an emergency landing due to the unsafe conditions and possibly of loosing another engine. They were flying a sorty and the nearest runway was Area 51. They radioed in and requested permission to make an emergency landing and were denied for obvious reasons. They were told to fly back to their home base, or try to get permission to land at an airport. Both being far away from their location, they requested again to land.