What were the flight numbers of the planes involved in 9/11?
Executive summary
Four commercial airliners were hijacked on September 11, 2001: American Airlines Flight 11 and United Airlines Flight 175 struck the World Trade Center, American Airlines Flight 77 hit the Pentagon, and United Airlines Flight 93 crashed in Pennsylvania after passengers resisted [1] [2] [3]. Federal records and memorial sites consistently identify the four flights as AA 11, UA 175, AA 77 and UA 93 [4] [3] [5].
1. The flight numbers everyone cites — and why they matter
Contemporary government records, museum accounts and major reference works all name the four hijacked jets by their commercial flight numbers: American Airlines Flight 11, United Airlines Flight 175, American Airlines Flight 77 and United Airlines Flight 93 [4] [3] [2]. The Federal Aviation Administration’s archived materials explicitly link its monitoring and investigations to “United Airlines Flights 175 and 93 and American Airlines Flights 11 and 77,” showing that these exact identifiers were central to official tracking and inquiry [4].
2. What each flight did that morning — the basic timeline
Available sources report that Flight 11 hit the North Tower at 8:46 a.m., Flight 175 struck the South Tower at 9:03 a.m., Flight 77 hit the Pentagon at 9:37 a.m., and Flight 93 was diverted and crashed in rural Pennsylvania after passengers resisted, thwarting an apparent attack on Washington targets [1] [2] [5]. This sequence is reflected in federal and public commemorations and remains the prevailing chronology in official histories and memorials [4] [6].
3. Why flight numbers feature in reporting, archives and memorials
Flight numbers are concise identifiers used by airlines, accident investigators and archives; the National Archives’ description of FAA holdings uses the flight numbers to organize materials related to monitoring and investigation, underlining their evidentiary value in records and inquiries [4]. Memorial institutions and the National Park Service similarly use these numbers to tell the human stories of crews and passengers, reinforcing the flights’ roles in public memory [3] [5].
4. The sensitivity around reusing those numbers
The flight numbers themselves have occasionally resurfaced in commercial operations, prompting public concern. Reporting from Reuters noted that in 2011 Continental (merged with United) inadvertently assigned the numbers 93 and 175 to active flights; United said the move was inadvertent and did not intend to reuse them permanently, and employee groups protested the insensitivity [7]. The Pentagon Memorial FAQ confirms that many carriers retired those numbers after the attacks [8].
5. What sources do not address in detail
Available sources do not mention any alternate or competing flight-number attributions for the four hijacked aircraft beyond the standard AA 11, UA 175, AA 77 and UA 93 labels; they do not document any credible official challenge to those identifications (not found in current reporting). Likewise, the provided material does not explore the technical registration numbers for each airframe in depth here — such details exist in specialized reports but are not covered in these excerpts (not found in current reporting).
6. How reporters and historians use these identifiers
Major historical summaries (Britannica), archival descriptions (National Archives/FAA) and memorial narratives (National September 11 Memorial & Museum, NPS) converge on the same flight-number narrative, which enables coordination between investigative records, commemoration and public education [2] [4] [3]. That convergence explains why these four flight numbers are the dominant, uncontested labels in public discourse.
7. A note on sources, accuracy and public memory
This account relies on official records and established reference and memorial institutions cited above; those sources treat the flight numbers as factual anchors in both the investigatory record and public remembrance [4] [3] [2]. Where sources document sensitivity or administrative slips — such as airlines temporarily reviving numbers — they show competing perspectives: airlines described incidents as inadvertent while employees and the public regarded reuse as insensitive [7].
If you want, I can list the aircraft registrations and passenger counts for each of the four flights using official FAA/NTSB and memorial sources. Available sources here reference passenger totals and some aircraft details but do not provide a consolidated table in these excerpts [9] [8].