United Airlines Flight 93

Information
United Airlines Flight 93 was a flight that was hijacked by four al-Qaeda terrorists on board, as part of the September 11 attacks. It crashed into a field in Somerset County, Pennsylvania, during an attempt by the passengers and crew to regain control. All 44 people on board were killed, including the four hijackers, but no one on the ground was injured. The aircraft involved, a Boeing 757, was flying United Airlines' daily scheduled morning flight from Newark International Airport in New Jersey to San Francisco International Airport in California.

Pilots
The pilots consisted of Captain Jason Dahl and First Officer LeRoy Homer Jr.

Background
The four hijackers checked in for the flight between 07:03 and 07:39 Eastern Time. At 07:03, Ghamdi checked in without any luggage while Nami checked in two bags. At 07:24, Haznawi checked in one bag and at 07:39, Jarrah checked in without any luggage. Haznawi was the only hijacker selected for extra scrutiny by the Computer Assisted Passenger Prescreening System (CAPPS). His checked bag underwent extra screening for explosives, with no extra scrutiny required by CAPPS at the passenger-security checkpoint. None of the security checkpoint personnel reported anything unusual about the hijackers.

Haznawi and Ghamdi boarded the aircraft at 07:39 and sat in first class seats 6B and 3D respectively. Nami boarded one minute later and sat in first class seat 3C. Ziad Jarrah called his girlfriend, Aysel Sengün, from a public telephone at the airport, repeating the words 'I love you' over and over. He boarded at 07:48 and sat in seat 1B. The aircraft was scheduled to depart at 08:00 and pushed back from gate A17 at 08:01. It remained delayed on the ground until 08:42 because of heavy airport congestion. The three other hijacked flights all departed within fifteen minutes of their scheduled times. By the time Flight 93 became airborne, Flight 11 was four minutes away from hitting the North Tower and Flight 175 was being hijacked; Flight 77 was climbing normally and was nine minutes away from being hijacked. By 09:02, one minute before Flight 175 hit the South Tower, Flight 93 reached its cruising altitude of 35,000 feet (11,000 m).

With the attacks unfolding, air traffic officials began issuing warnings through the Aircraft Communication Addressing and Reporting System (ACARS). Ed Ballinger, the United flight dispatcher, began sending text cockpit warnings to United Airlines flights at 09:19, 17 minutes after he became aware of Flight 175's impact. Ballinger was responsible for multiple flights, and he sent the message to Flight 93 at 09:23. Ballinger received a routine ACARS message from Flight 93 at 09:21. At 09:22, after learning of the events at the World Trade Center, LeRoy Homer's wife, Melody Homer, had an ACARS message sent to her husband in the cockpit asking if he was all right. At 09:24, Flight 93 received Ballinger's ACARS warning, "Beware any cockpit intrusion—two a/c [aircraft] hit World Trade Center". At 09:26, Captain Jason Dahl sent an ACARS message back, "Ed, confirm latest mssg plz —Jason". At 09:27:25, the flight crew responded to routine radio traffic from air traffic control. This was the last communication made by the flight crew before the hijacking.

The hijacking on Flight 93 began at 09:28. By this time, Flights 11 and 175 had already crashed into the World Trade Center and Flight 77 was within 9 minutes of striking the Pentagon. The hijackers on those flights had waited no more than 30 minutes to commandeer the aircraft, most likely striking after the seat-belt sign had been turned off and cabin service had begun. It is unknown why the hijackers on Flight 93 waited 46 minutes to begin their assault. At 09:28:17, First Officer LeRoy Homer managed to transmit to the ground, shouting, "Mayday! Mayday! Get out!" over the radio amid sounds of violence. A Cleveland Air Traffic Controller replied, "Somebody call Cleveland?" but received no reply.

Thirty-five seconds after the first Mayday call, the crew made another transmission. Homer shouted, "Mayday! Mayday! Get out of here! Mayday! Get out of here!" The flight dropped 685 feet (209 m) in half a minute before the hijackers managed to stabilize the aircraft. The exact time at which Flight 93 came under the hijackers' control cannot be determined. Officials believe that at 09:28, the hijackers assaulted the cockpit and moved the passengers to the rear of the plane at the same time to minimize any chance that either the crew or the passengers would interfere with the attack. The other hijacked flights were taken by five-man teams, but Flight 93 had only four hijackers, leading to speculation of a possible 20th hijacker. The 9/11 Commision believed that Mohammed al-Qahtani was the likely candidate for this role, but was unable to participate as he had been denied entry into the United States one month earlier. With many passengers saying in phone calls that they saw only three hijackers, the 9/11 Commission believed Jarrah remained seated until the crew were overpowered and passengers were moved to the back of the aircraft and then took over the flight controls out of sight of the passengers.

The flight recordings revealed that Captain Jason Dahl and First Officer LeRoy Homer survived the initial attack and were still alive after the hijackers took over the plane. Dahl and Homer took actions to interfere with the hijackers, including disengaging the autopilot just before the hijackers took over in order to prevent them from aiming the plane at Washington, D.C., and switching the output of the pilots' microphones from the cabin address speakers to the radio transmitter so that Jarrah's attempts to communicate with the passengers would instead be heard by air traffic controllers. Dahl "stayed in the cockpit alone with the hijacker-pilot, injured but not dead", while Homer was "knocked unconscious and dragged from the cockpit".

The flight transcript suggests that at least two hijackers were in the cockpit. Ziad Jarrah was identified as the pilot and is heard calling another hijacker "Saeed", indicating that Saeed al-Ghamdi, who also trained in flight simulators, was helping Jarrah with the controls.

The cockpit voice recorder began recording the final 30 minutes of Flight 93 at 09:31:57. At this moment, it recorded Jarrah announcing, "Ladies and gentlemen: here the captain. Please sit down, keep remaining seating. We have a bomb on board. So sit." The controller understood the transmission, but responded, "Calling Cleveland center, you're unreadable. Say again, slowly." The cockpit recording captured Dahl moaning and Jarrah telling him in English to sit down and to stop touching something (presumably the controls); Jason Dahl's wife, Sandy Dahl, listening to the cockpit voice recorder, commented that Jarrah "was fussing at my husband...he was speaking in English, and he spoke Arabic anytime he was talking with the other hijackers. Jason made moaning sounds after that. It sounded like he was trying to mess with stuff or get up, because the hijacker pilot kept telling him to stop and to sit down."

A woman, presumably first-class flight attendant Debbie Welsh, is heard being held captive in the background and is heard struggling with the hijackers and pleading, "Please, please, don't hurt me". Unable to engage the autopilot, Jarrah turned the plane and headed east at 09:35:09. The aircraft ascended to 40,700 feet (12,400 m) and air traffic controllers immediately moved several aircraft out of Flight 93's flightpath. The woman in the cockpit is heard to say, "I don't want to die, I don't want to die" before being killed or otherwise silenced, followed by one of the hijackers saying in Arabic, "Everything is fine. I finished."

At 09:39, two minutes after Flight 77 impacted the Pentagon, air traffic controllers overheard Jarrah say, "Ah, here's the captain: I would like you all to remain seated. We have a bomb aboard, and we are going back to the airport, and we have our demands. So please remain quiet." Air traffic controllers did not hear from the flight again. Passengers and crew began making phone calls to officials and family members starting at 09:30 using GTE airphones and mobile phones. Altogether, the passengers and crew made 35 airphone calls and 2 cell phone calls from the flight. Ten passengers and two crew members were able to connect, providing information to family, friends, and others on the ground.

The airplane plummeted into a nosedive with the yoke turned hard to the right. The airplane rolled upside down, and one of the hijackers began shouting the takbir. Among the continued sounds of the passenger counterattack, the aircraft picked up speed, whooshing and shrieking were picked up on the recorder, and the hijackers inside the cockpit are heard yelling "No!" over the sound of breaking glass. The final spoken words on the recorder were a calm voice in English instructing, "Pull it up." The plane then crashed into an empty field in Stonycreek, Pennsylvania, about 20 minutes' flying time from Washington, D.C. The last entry on the voice recorder was made at 10:03:09. The last piece of flight data was recorded at 10:03:10. There is controversy between some family members of the passengers and the investigative officials as to whether the passengers managed to breach the cockpit. The 9/11 Commission Report concluded that "the hijackers remained at the controls but must have judged that the passengers were only seconds from overcoming them." Many of the passengers' family members, having heard the audio recordings, believe that the passengers breached the cockpit and killed at least one of the hijackers guarding the cockpit door; some interpreted the audio as suggesting that the passengers and hijackers struggled for control of the yoke.

At 10:03:11, near Indian Lake and Shanksville, Pennsylvania, the plane crashed into a field near a reclaimed coal strip mine known as the Diamond T. Mine owned by PBS Coals in Stonycreek Township in Somerset County. The National Transportation Safety Board reported that the flight impacted at 563 mph (906 km/h, 252 m/s, or 489 knots) at a 40-degree nose-down, inverted attitude. The impact left a crater eight to ten feet deep (c. 3 m), and 30 to 50 feet wide (c. 12 m). All 44 people on board died. Many media reports and eyewitness accounts said the time of the crash was 10:06 or 10:10; an initial analysis of seismographic data in the area concluded that the crash occurred at 10:06, but the 9/11 Commission report states that this analysis was not definitive and was retracted. Other media outlets and the 9/11 Commission reported the time of impact as 10:03, based on when the flight recorders stopped, analysis of radar data, infrared satellite data, and air traffic control transmissions.

Kelly Leverknight, a local resident, was watching news of the attacks when she heard the plane. "I heard the plane going over and I went out the front door and I saw the plane going down. It was headed toward the school, which panicked me, because all three of my kids were there. Then you heard the explosion and felt the blast and saw the fire and smoke." Another witness, Eric Peterson, looked up when he heard the plane, "It was low enough, I thought you could probably count the rivets. You could see more of the roof of the plane than you could the belly. It was on its side. There was a great explosion and you could see the flames. It was a massive, massive explosion. Flames and then smoke and then a massive, massive mushroom cloud." Val McClatchey had been watching footage of the attacks when she heard the plane. She saw it briefly, then heard the impact. The crash knocked out the electricity and phones. McClatchey grabbed her camera and took the only known picture of the smoke cloud from the explosion. In September 2011, shortly before the 10th anniversary of the attacks, a video of the rising smoke cloud filmed by Dave Berkebile (who had died by 2011) from his yard ​2 1/2 miles away from the crash site was published on YouTube.

The first responders arrived at the crash site after 10:06. Cleveland Center controllers, unaware the flight had crashed, notified the Northeast Air Defense Sector (NEADS) at 10:07 that Flight 93 had a bomb on board and passed the last known position. This call was the first time the military was notified about the flight. Ballinger sent one final ACARS message to Flight 93 at 10:10, "Don't divert to DC. Not an option." He repeated the message one minute later. The Herndon Command Center alerted FAA headquarters that Flight 93 had crashed at 10:13. NEADS called the Washington Air Route Traffic Control Center for an update on Flight 93 and received notification that the flight had crashed.

At 10:37, CNN correspondent Aaron Brown, covering the collapse of the World Trade Center, announced, "We are getting reports and we are getting lots of reports and we want to be careful to tell you when we have confirmed them and not, but we have a report that a 747 is down in Pennsylvania, and that remains unconfirmed at this point." He followed that up at 10:49 by reporting that, "We have a report now that a large plane crashed this morning, north of the Somerset County Airport, which is in western Pennsylvania, not too terribly far from Pittsburgh, about 80 miles or so, a Boeing 767 jet. Don't know whose airline it was, whose airplane it was, and we don't have any details beyond that which I have just given you." In the confusion, he also erroneously reported a second hijacked plane heading for the Pentagon after the crash of the first.