At least two of the four flight attendants who will be on American Airlines Flight 77—the third plane to be hijacked—on 9/11 are not originally scheduled to be on this plane, and are only assigned to it shortly before—or early in the morning of—September 11: 
Michele Heidenberger regularly flies from Washington’s Reagan National Airport to Dallas. But she will tell a colleague she is working Flight 77 on 9/11 as she is building up vacation time so she can go to Italy in October. [Murphy, 2006, pp. 42-43] Renee May is assigned to Flight 77 early in the morning of 9/11. Before she is offered the flight, American Airlines asks another attendant, Lena Brown, to take it, but Brown says she is unable to get to the airport in time. [Atlanta Journal-Constitution, 8/9/2002; Daily Reflector, 9/11/2002]
One of the pilots—either Charles Burlingame or David Charlebois—is also not originally scheduled to be on Flight 77 on September 11, and only accepts the flight shortly before then (see Shortly Before September 11, 2001). [New York Times, 9/13/2001] Many of the flight attendants who will be on the other three hijacked planes are also only assigned to those flights shortly before 9/11 (see Shortly Before September 11, 2001-Early Morning September 11, 2001, Shortly Before September 11, 2001, and Shortly Before September 11, 2001).
9:12 a.m. September 11, 2001: Flight 77 Attendant Calls Parents and Confirms Hijacking, but Accounts Are Contradictory
Renee May, a flight attendant on Flight 77, calls her parents in Las Vegas and reports her plane has been hijacked. [9/11 Commission, 7/24/2004, pp. 9; US District Court for the Eastern District of Virginia, Alexandria Division, 7/31/2006] According to author Tom Murphy, May previously tried calling the American Airlines flight services office at Washington’s Reagan National Airport, but all the lines there were busy. [Murphy, 2006, pp. 56-57] However, a summary of the phone calls made from the four hijacked planes that is presented at the 2006 Zacarias Moussaoui trial will make no mention of this earlier call. May’s first attempt at calling her parents, at 9:11 a.m., had not connected, but her second attempt a minute later is successful, and the call lasts for two-and-a-half minutes. [9/11 Commission, 8/26/2004, pp. 31; US District Court for the Eastern District of Virginia, Alexandria Division, 7/31/2006] According to reports shortly after 9/11 in the Las Vegas Review-Journal, May makes her call using a cell phone. [Las Vegas Review-Journal, 9/13/2001; Las Vegas Review-Journal, 9/15/2001] But at the Moussaoui trial it will be claimed she uses an Airfone. [US District Court for the Eastern District of Virginia, Alexandria Division, 7/31/2006, pp. 7 
] According to most accounts, including that of the 9/11 Commission, she speaks to her mother, Nancy May. [Las Vegas Review-Journal, 9/13/2001; 9/11 Commission, 7/24/2004, pp. 9; US District Court for the Eastern District of Virginia, Alexandria Division, 7/31/2006, pp. 7 ] But according to Murphy, she speaks with her father, Ronald May. [Murphy, 2006, pp. 57] Renee reports that her plane is being hijacked. [9/11 Commission, 8/26/2004, pp. 31] Although it will be officially claimed that there are five hijackers on Flight 77, she says six individuals have taken over the plane (see Between 9:12 a.m. and 9:15 a.m. September 11, 2001). [Federal Bureau of Investigation, 9/27/2001; 9/11 Commission, 7/24/2004, pp. 2-3 and 9] Renee says the hijackers have moved people to the rear of the aircraft, though it is unclear whether she is referring to all of the passengers or just the flight’s crew. She tells her parent (either her mother or father, depending on the account) to call American Airlines and inform it of the hijacking. She gives three numbers in Northern Virginia to call. Before the time Flight 77 crashes, Renee May’s mother (or her father, according to Murphy) is able to contact an American Airlines employee at Reagan National Airport and pass on what their daughter has reported (see (Between 9:15 a.m. and 9:37 a.m.) September 11, 2001). [9/11 Commission, 8/26/2004, pp. 31; Murphy, 2006, pp. 57]
Between 9:12 a.m. and 9:15 a.m. September 11, 2001: Flight Attendant Describes Six Hijackers on Flight 77
In a phone call from Flight 77, flight attendant Renee May describes six hijackers on her plane, yet official accounts will state there are only five. May is able to call her parents from Flight 77 to report that her plane has been hijacked (see (9:12 a.m.) September 11, 2001). She says six individuals have carried out the hijacking. [9/11 Commission, 7/24/2004, pp. 9; 9/11 Commission, 8/26/2004, pp. 31] Yet, despite this, the official claim put forward by the FBI and later the 9/11 Commission will be that there are five hijackers—not six—on this flight. [Federal Bureau of Investigation, 9/27/2001; 9/11 Commission, 8/26/2004, pp. 27] Apparently, the only other person to make a phone call from Flight 77 is passenger Barbara Olson, who reaches her husband (see (Between 9:15 a.m. and 9:25 a.m.) September 11, 2001). [CNN, 9/12/2001; 9/11 Commission, 1/27/2004 ] But Olson does not appear to make any reference to the number of hijackers on the plane. [Federal Bureau of Investigation, 9/11/2001; CNN, 9/14/2001; 9/11 Commission, 7/24/2004, pp. 9]
Between 9:15 a.m. and 9:37 a.m. September 11, 2001: Parent of Flight Attendant Informs American Airlines of Daughter’s Call from Flight 77
At some time before the Pentagon is hit, one of the parents of flight attendant Renee May call an American Airlines employee at Reagan National Airport just outside Washington, DC, and report that their daughter has contacted them from Flight 77, which has been hijacked. May called her parents at 9:12 a.m., reported that her plane was being hijacked, and asked them to pass this information on to American Airlines (see (9:12 a.m.) September 11, 2001). [9/11 Commission, 8/26/2004, pp. 31] The Las Vegas Review-Journal reports that it is May’s mother, Nancy May, who makes the call to American Airlines. [Las Vegas Review-Journal, 9/13/2001] This claim is repeated at the 2006 Zacarias Moussaoui trial. [US District Court for the Eastern District of Virginia, Alexandria Division, 7/31/2006, pp. 7 ] But according to author Tom Murphy, it is her father, Ronald May, who makes the call. [Murphy, 2006, pp. 57] The parent describes the information provided by their daughter, including her flight number and her phone number on board the plane. According to the 9/11 Commission, the American Airlines employee initially thinks May’s mother (who the Commission indicates makes the call) is talking about the aircraft that crashed into the World Trade Center. But Nancy May repeats that she is referring to Flight 77, which is still in the air. (The error could possibly be because, by 9:08 a.m., officials at American Airlines’ System Operations Control in Texas mistakenly concluded that the second aircraft to hit the World Trade Center may have been Flight 77 (see 9:08 a.m. September 11, 2001).) [9/11 Commission, 8/26/2004, pp. 30-31] The employee, a secretary, then passes on the information about May’s call to Toni Knisley, a flight service manager at the airport. Knisley rushes to her office and enters May’s employee number into the computer to call up her schedule. This shows she was booked on Flight 77, Washington Dulles Airport to Los Angeles, scheduled to depart at 8:10 a.m. Knisley tries to log onto the flight to view its status, but the information is blocked, so she cannot see if it is still flying or where it is. [Murphy, 2006, pp. 56-57] (It is possible the information is blocked as a result of American Airlines having already initiated “lockout” procedures to protect information about Flight 77 (see 9:05 a.m. September 11, 2001).)
