Immediately after the attacks on New York and Washington DC, grounded aircraft security checks were scourging the planes for anything suspicious. There were some instances where box cutters and knives were found thru-ought the country. Mainly hidden underneath seats and behind food trays behind seats. American Airlines Flight 160 out of San Diego for instance where box cutters were found under passenger seats. United Airlines Flight 23 had 3 Arab males who were seemingly involved in the attacks of 9/11 as their luggage contained box cutters, Al Qaeda manual and even a flight certificate from Florida where other 9/11 hijackers trained at. A Delta flight that was supposed to depart Boston's Logan airport later in the afternoon had two knives underneath seats.
The plan was for the operation to be much bigger than anyone had realized, it was to follow the original idea of two men Ramzi Yousef (1993 WTC Bombing) and Khalid Sheikh Muhammad (KSM)….the Bojinka Plot. For Yousef and KSM the initial plan for Bojinka Plot was to secretly construct and plant 12 timing devices on board airliners departing from SE Asia to the United States and have them all explode over the Pacific Ocean just 2 minutes apart from one another. Along with assassinating Pope John Paul II and U.S President Bill Clinton.
This operation was modified by KSM and Abdul Hakim Murad in 1997 after Yousef’;s arrest and conviction for his participation in the 1993 WTC Bombing. With this idea of using planes as the weapon instead of using bombs, which would garner the most attention, KSM went to Osama Bin Laden with an idea. The plan is simple, have 10 operatives learn to pilot planes and have them hijack the aircraft and crash them into high valued targets inside the United States, with KSM as the 10th pilot where he would slaughter all the males and then land it at a designated spot where he would give a media interview describing the goal of such an operation.
Bin Laden exclaimed that 10 planes would be too much responsibility. According to testimonies from KSM, Abu Zubaydah and Ramzi bin al-Shibh’s….Bin Laden told KSM to hijack only 4 planes and that he would select the pilots. KSM would select the targets. Thus the 9/11 operation had began, but it was derived straight from the Bojinka Plot…which was known for 6 years by the FBI where they obtained the laptop of Ramzi Yousef in the Philippines while the operation was underway.