Flight175. Hijacking Flight 175 was hijacked between 08:42 and 08:46, while Flight11 was just minutes away from hitting the North Tower. It is believed that hijackers Banihammad and al-Shehri forcibly entered the cockpit and attacked the pilots while the al-Ghamdis commanded passengers and crew to the aft of the cabin and al-Shehhi took over the controls. Knives were used to stab the flight crew and kill both pilots. One passenger also reported, during a phone call, the use of mace and bomb threats. The first operational evidence that something was abnormal on Flight175 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 Flight11, which had turned its transponder off, Flight175's flight data could still be properly monitored. Also, at 08:51, Flight175 changed altitude. Over the next three minutes, the controller made five unsuccessful attempts to contact Flight175 and worked to move other aircraft in the vicinity away from Flight175. At 08:55 a supervisor at the New York Air Traffic Control Center notified the center's operations manager of the Flight175 hijacking. Dave Bottigliathe controller who was handling both Flight11 and Flight175remarked, "We might have a hijack over here, two of them." Near-misses Around this time, the flight had a near midair collision with Delta Air Lines Flight2315 flying from Hartford to Tampa, reportedly missing the plane by only . Bottiglia yelled at the Delta pilot to make collision avoidance maneuvers, adding, "I think [Flight 175] has been hijacked. I don’t know his intentions. Take any evasive action necessary." Moments before Flight175 crashed, it narrowly avoided colliding with Midwest Express Flight7, which was flying from Milwaukee to New York. Calls Flight attendant Robert Fangman and passengers Peter Hanson and Brian David Sweeney made phone calls from GTE airphones in the rear of the aircraft. Airphone records also indicate that passenger Garnet Bailey made four phone call attempts to his wife. At 08:52, Robert Fangman called a United Airlines maintenance office in San Francisco and spoke with Marc Policastro. Fangman reported the hijacking and said the hijackers were likely flying the plane. He mentioned that both pilots were dead and that a flight attendant had been stabbed. After a minute and 15 seconds, the call was disconnected. Policastro