8:30 a.m.-10:00 a.m. September 11, 2001: NASA Plane Flying Routine Mission over New York State; Passes Flight 93

A special aircraft operated by NASA is in the air over western New York State at the time of the terrorist attacks and, at one point, a large aircraft, which those on board later learn is the hijacked Flight 93, flies less than 1,000 feet below it. [Space Center Roundup, 9/2002 ] The plane, NASA 931, is a modified KC-135—a four-engine military aircraft similar to the Boeing 707. [National Aeronautics and Space Administration, 10/2000, pp. 28; National Aeronautics and Space Administration, 10/29/2004] It is used by NASA for reduced gravity research, and is known as the “Weightless Wonder” or sometimes the “Vomit Comet.” The aircraft creates weightless conditions for brief periods by flying up and down in large parabolic arcs. [NASAexplores, 1/30/2003] It is regularly operated from NASA’s Glenn Research Center in Cleveland, Ohio, next to Cleveland Hopkins International Airport, and usually flies four days a week. [National Aeronautics and Space Administration, 10/2000, pp. 140; National Journal’s Technology Daily, 11/27/2002; National Aeronautics and Space Administration, 10/29/2004] A typical flight lasts two to three hours and consists of the plane flying 40 to 60 parabolas. [NASAexplores, 1/30/2003]
Scientists from Houston Conducting Microgravity Experiments – A team of scientists from NASA’s Johnson Space Center in Houston, Texas, has flown to Cleveland to conduct microgravity experiments on the KC-135. [Cleveland Free Times, 9/6/2006] Dominic Del Rosso, the test director on the plane, will later recall that the team is flying over western New York State when the terrorist attacks occur. During the routine mission, the KC-135 cruises back and forth along the New York shore of Lake Ontario, climbing and descending to create a freefall condition to simulate microgravity. Del Rosso will comment, “To think that this type of maneuver might ever seem threatening never crossed my mind until [September 11].” The plane’s crew members are notified at some point that a large plane is intersecting their flight path less than 1,000 feet below them, instead of the usual 2,000-foot minimum distance. They will later learn that this aircraft is the hijacked Flight 93, which crashes in Pennsylvania (see (10:06 a.m.) September 11, 2001). Del Rosso will recall, “After the unwanted flyby, we landed having no idea why or what was going on.” [Space Center Roundup, 9/2002 ] The scientists are unable to return to Houston on this day, as scheduled, after the FAA orders all planes to land (see (9:45 a.m.) September 11, 2001), and so have to be put up in a hotel in Cleveland. [Cleveland Free Times, 9/6/2006]