Basics about the flight:
United Airlines Flight 23, a Boeing 767 bound from JFK International Airport in New York to Los Angeles, cancels its takeoff and may thus avoid becoming the morning’s fifth hijacked plane. It was scheduled to depart at 8:30 a.m., but was late in pushing back from the gate and is still waiting in line to take off.
http://www.historycommons.org/context.jsp?item=a900hijackingaverted">United 23 cancels takeoff
9/13/01 AP account:
Three males traveling together became upset and refused to disembark. The argument with a member of the flight crew became so heated that the crew member called airport security.
But before security arrived, the men had vanished, said the source, who spoke on the condition of anonymity. WNBC-TV first reported the incident on Wednesday.
http://www.usatoday.com/news/nation/2001/09/13/investigate-jfk.htm">FBI investigates incident at JFK airport
NY Times September 14, 2001 (Account of strange activity on 9/13/01):
Ten people were taken into custody yesterday at Kennedy International and La Guardia Airports shortly after they were reopened for the first time since the terrorist attacks on Tuesday. The authorities then abruptly shut all three major New York-area airports again.
...
Investigators said they believed that at least one of those taken into custody at Kennedy yesterday was among a group who tried to board a Los Angeles-bound plane at the airport on Tuesday morning, around the time that three other West Coast-bound planes were slamming into the twin towers and the Pentagon outside Washington.
In that incident, the flight was canceled at Kennedy just as passengers were beginning to board United Airlines Flight 23 to Los Angeles, investigators said. ''These guys got belligerent, and said something like, 'We've got to be on this plane,' '' an official said. ''They expressed a desire to remain on the plane and resisted getting off.''
The men, who appeared to be of Arab descent, then fled before they could be questioned by law enforcement officers, investigators said.
http://query.nytimes.com/gst/fullpage.html?res=9E06E2DD1E38F937A2575AC0A9679C8B63">LOCAL AIRPORTS SHUT AFTER AN ARREST
NY Times October 20, 2001:
When the captain announced that the plane was returning to the gate, four male passengers described as Middle Eastern in appearance stood up and began urgently consulting with each other, two aviation officials said. The men refused orders from flight attendants to return to their seats, the officials said.
The cockpit crew did not wait for the men to be seated but decided to taxi back to the gate anyway, the officials said. ''As soon as the door opened, these four guys bolted,'' said one of the officials. The other added that the F.B.I. later interviewed the crew about the incident.
http://query.nytimes.com/gst/fullpage.html?res=9F06E2D6103EF933A15753C1A9679C8B63">A NATION CHALLENGED: AN INQUIRY; F.B.I. Asks if Hijacking Plot Included Plane at Kennedy
Daily Herald, April 14, 2004:
Thanks to Ballinger's quick call, the flight crew told passengers it had a mechanical problem and immediately returned to the gate.
Later, Ballinger was told six men initially wouldn't get off the plane. Later, when they did, they disappeared into the crowd, never to return. Later, authorities checked their luggage and found copies of the Qu'ran and al-Qaida instruction sheets.
...
The suspect passengers were never found, and are probably still at large, Kirk said.
"When all we have is a photo from a fake ID," he added, "the chances of finding him in Afghanistan or Pakistan are rather slim."
http://www.house.gov/apps/list/hearing/il10_kirk/news040414_flight.html">Suburban Flight Dispatcher to Recount Worst Day
There is another account in the book
Touching History by Lynn Spencer. According to her account a flight attendant alerted the pilots that four Arab men were seated in first class. There is no description of their conduct or why the flight attendant was suspicious. After the plane returned, the four men simply disappeared. Spencer's account doesn't mention any arguments between the men and airline staff.
There are many odd aspects in these accounts:
1) The contradictory details. For example, were there three, four or six suspect passengers?
2) What sort of idiot terrorist would come back on 9/13? It is reminiscent of Mohammed Salemeh trying to get his deposit back for the Ryder van after the WTC '93 bombing.
3) Al-Qaida instruction sheets. Fake ID's. Failed to pick up their luggage. The flight crew was interviewed six times. First class tickets. Cross country flight. 767. Same time frame as the hijacked flights. Yet they simply got away? That is absurd.
4)Al Qaeda (AFAIK) has always gone along with the 19 hijackers + 4 planes narrative. KSM and bin al-Shibh made a big deal out of telling Yosri Fouda the assigned names of the 19 hijackers. Why wouldn't al Qaeda want to make the FBI look bad and reveal that there were more hijackings planned?
5)I know we are told the hijacked plane manifests are a-ok and only a conspiracy nut would dare question their validity. The problem is that the use of real names has never made any sense. After all, the FBI knew alHazmi and alMihdhar were in the US in late August. CIA withholding was no longer a factor. If the FBI had only shared the names with FAA intel then they would have known that alHazmi and alMihdhar were booked for Flight 77 on 9/11. Thus, the use of real names is bizarre terrorist tradecraft. We also had some confusion with early news reports stating that Adnan Bukhari, Ameer Bukhari and Mosear Caned were hijackers. It all leads one to wonder what names were truly on the original manifests.
United 23 appears to offer extraordinary potential to clear up some mysteries of 9/11 since it seems quite possible that al Qaeda operatives intended to hijack the plane.