United Airlines Flight 175

Information
United ight 175 was a flight from Logan International Airport, in Boston, Massachusetts, to Los Angeles International Airport, in Los Angeles, California. On September 11, 2001, the Boeing 767 operating the route was hijacked by five al-Qaeda terrorists and was deliberately crashed into the South Tower of the World Trade Center in New York City, killing all 65 people aboard and an unconfirmed number in the building's impact zone.

Pilots
The pilots consisted of Captain Victor Saracini and First Officer Michael Horrocks.

Background
Hamza al-Ghamdi and Ahmed al-Ghamdi checked out of their hotel and called a taxi to take them to Logan International Airport. They arrived at the United Airlines counter in Terminal C at 06:20 Eastern Time and Ahmed al-Ghamdi checked in two bags. Both hijackers indicated they wanted to purchase tickets, though they already had paper tickets. They had trouble answering the standard security questions, so the counter agent repeated the questions very slowly until satisfied with their responses. Hijacker pilot Marwan al-Shehhi checked in a single bag at 06:45, and the other remaining hijackers, Fayez Banihammad and Mohand al-Shehri, checked in at 06:53. Banihammad checked two bags. None of the hijackers were selected for extra scrutiny by the Computer Assisted Passenger Prescreening System (CAPPS).

Shehhi and the other hijackers boarded Flight 175 between 07:23 and 07:28. Banihammad boarded first and sat in first class seat 2A, while Mohand al-Shehri was in seat 2B. At 07:27, Shehhi and Ahmed al-Ghamdi boarded, and sat in business class seats 6C and 9D, respectively. A minute later, Hamza al-Ghamdi boarded, and sat in 9C.

The flight was scheduled to depart at 08:00 for Los Angeles. Fifty-one passengers and the five hijackers boarded the 767 through Terminal C's Gate 19. The plane pushed back at 07:58 and took off at 08:14 from runway 9, about the same time Flight 11 was hijacked. By 08:33, the aircraft reached cruising altitude of 31,000 feet, which is the point when cabin service would normally begin. At 08:37, air traffic controllers asked the pilots of Flight 175 whether they could see American Airlines Flight 11. The crew responded that Flight 11 was at 29,000 feet, and controllers ordered Flight 175 to turn and avoid the aircraft. The pilots declared that they had heard a suspicious transmission from Flight 11 upon takeoff. "Sounds like someone keyed the mic and said everyone stay in your seats", the flight crew reported. This was the last transmission from Flight 175.

It is estimated that Flight 175 was hijacked between 08:42 and 08:46, while Flight 11 was just minutes away from hitting the North Tower. According to Flight 175: As the World Watched, it is believed that hijackers Fayez Banihammad and Mohand al-Shehri forcibly entered the cockpit and killed the pilots while Hamza al-Ghamdi and Ahmed al-Ghamdi started moving passengers and crew to the back of the aircraft. The first operational evidence that something was abnormal on Flight 175 came at 08:47, when the plane's transponder signal changed twice within the span of one minute, and the aircraft began deviating from its assigned course. However, the air traffic controller in charge of the flight did not notice until minutes later at 08:51. Unlike Flight 11, which had turned its transponder off, Flight 175's flight data could still be properly monitored. Also, at 08:51, Flight 175 changed altitude. Over the next three minutes, the controller made five unsuccessful attempts to contact Flight 175 and worked to move other aircraft in the vicinity away from Flight 175.

At 09:01, two minutes before impact as Flight 175 continued its descent into Lower Manhattan, the New York Center alerted another nearby Air Traffic Facility responsible for low-flying aircraft, which was able to monitor the aircraft's path over New Jersey, and then over Staten Island and Upper New York Bay in its final moments. (Flight 175 came in from the southwest, apparently heading for the Empire State Building, but turned right, then left into the South Tower.)

Flight 175 explodes after hitting the South Tower.

At exactly 9:03:02, Flight 175 crashed nose-first into the southern façade of the South Tower of the World Trade Center killing the Passengers and Terrorist on impact, at a speed of approximately 590 mph (950 km/h, 264 m/s, or 513 knots) and striking between floors 77 and 85 with approximately 10,000 U.S. gallons (38,000 L; 8,300 imp gal) of jet fuel on board. The youngest person on Flight 175 was 2½-year-old Christine Hanson of Groton, Massachusetts, and the oldest was 80-year-old Dorothy DeAraujo of Long Beach, California. Hundreds more were killed within the tower and from its ensuing explosion, fires, and eventual collapse. It is estimated that 637 people were killed instantly or trapped at and above the floors of impact in the South Tower.

Based on the position of the aircraft from eyewitness statements and video footage, the aircraft was in a banking left turn in its final moments, as it appeared that the plane might have otherwise missed the building or merely scraped it with its wing. Upon crashing, the plane was banked left. Those who were on the left side of the plane would, therefore, have had a clear view of the towers approaching, with one burning, until the final moment of the flight.

By the time Flight 175 struck the South Tower, multiple media organizations were already covering the crash of Flight 11, which had hit the North Tower 17 minutes earlier. The image of Flight 175's crash was thus caught on video from multiple vantage points on live television and amateur video, while approximately 100 cameras captured Flight 175 in photographs before it crashed. Video footage of the crash was replayed numerous times in news broadcasts on the day of the attacks and in the following days, before major news networks put restrictions on use of the footage.

After the plane penetrated through the tower, part of the plane's landing gear and fuselage came out the north side of the tower and crashed through the roof and two of the floors of 45–47 Park Place, between West Broadway and Church Street, 600 feet (180 meters) north of the former World Trade Center. Three floor beams of the top floor of the building were destroyed, causing major structural damage.

Trivia
The flight had a near midair collision with Delta Air Lines Flight 2315, flying from Hartford to Tampa, reportedly missing the plane by only 300 feet (90 m), as air traffic controller Dave Bottiglia frantically tried to tell the Delta pilot to take evasive action. Bottiglia was the first person in the control center to realize that Flight 175 was hijacked when he gave directions for a turn. Flight 175 did not respond, instead accelerating and heading toward the Delta plane. The controller commanded the Delta pilot, "Take any evasive action necessary. We have an airplane that we don't know what he's doing. Any action at all." Moments before Flight 175 crashed, it avoided another near collision with Midwest Express Flight 7, which was flying from Milwaukee to New York.