After 9/11, cellular experts said that calls were able to be placed from the hijacked planes, and that they were surprised that they lasted as long as they did. They said that the only reason that the calls went through in the first place is that the aircraft were flying so close to the ground.[134] Alexa Graf, an AT&T spokesperson said it was almost a fluke that the calls reached their destinations.[135] Other industry experts said that it is possible to use cell phones with varying degrees of success during the ascent and descent of commercial airline flights.[136] Marvin Sirbu, professor of Engineering and Public Policy at Carnegie Mellon University said on September 14, 2001, that "The fact of the matter is that cell phones can work in almost all phases of a commercial flight."[136]

According to the 9/11 Commission Report, 13 passengers from Flight 93 made a total of over 30 calls to both family and emergency personnel (twenty-two confirmed air phone calls, two confirmed cell phone and eight not specified in the report). According to Debunk911myths.org, all but two calls from Flight 93 were made on air phones, not cell phones, and both calls lasted about a minute before being dropped.[137] Brenda Raney, Verizon Wireless spokesperson, said that Flight 93 was supported by several cell sites.[135] There were reportedly three phone calls from Flight 11, five from Flight 175, and three calls from Flight 77. Two calls from these flights were recorded, placed by flight attendants Madeleine Sweeney and Betty Ong on Flight 11.