United Airlines Flight 175 as part of the September 11 attacks.
Born in Saudi Arabia, Ghamdi left his family to fight in Chechnya and was probably sent to Al-Qaeda training camps in Afghanistan where he was chosen to participate in the 9/11 attacks.
He arrived in the United States in May 2001 on a tourist visa. On September 11, 2001, Ghamdi boarded United Airlines Flight 175 and hijacked the plane along with four other terrorists so that the plane could be crashed into the South Tower of the World Trade Center.
Ghamdi purchased his own eTicket for Flight 175 on August 29, using his Visa card. The FBI also claimed that he also purchased an eTicket for a "Flight 7950" from Los Angeles to San Francisco, although it does not give the projected date of flight.
On August 30, Hamza bought Ahmed al-Ghamdi an identical eTicket for Flight 175, and bought them each one-way tickets on an AirTran flight on September 7, from Fort Lauderdale to Boston. However, Ghamdi instead went with Mohand al-Shehri to Newark, New Jersey on $139.75 tickets purchased from the Mile High Travel agency in Lauderdale-by-the-Sea.
Hamza and Ahmed al-Ghamdi stayed at the Charles Hotel in Cambridge, Massachusetts. On September 8 they checked out of the hotel, and moved into the Days Hotel on Soldiers Field Road in Brighton, Boston, Massachusetts where they remained up until the attacks.
On the morning of September 11, 2001, Hamza left the hotel with Ahmed al-Ghamdi. The two men shared a taxicab to get to Logan International Airport, where they boarded Flight 175. Hamza al-Ghamdi and his older brother Ahmed pushed the passengers and crew to the back of the plane while Fayez Banihammad and Mohand al-Shehri killed the pilots allowing Marwan al-Shehhi to take control of the plane.