Should terrorists launch new attacks, we believe their preferred targets will be U.S. Government facilities and national symbols, financial and transportation infrastructure nodes, or public gathering places. Civil aviation remains a particularly attractive target in light of the fear and publicity that the downing on an airline would evoke.

— National Intelligence Estimate, 1995. In 1998 and 1999 the FAA intelligence unit further warned that terrorists might hijack a plane and use it as a weapon. Both warnings are contained in the 9/11 Commission report, redacted when first issued but following a declassification review made public in September 2005.

I would like to fly in a professional like manners one of the big airliners. I have to made my mind which of the followwing: Boeing 747, 757, 767, 777 and or Airbus A300 (it will depend on the cost and which one is easiest to learn).
The level I would like to achieve is to be able to takeoff and land, to handle communication with ATC, to be able to successfully navigate from A to B (JFK to Heathrow for example).
In a sense to be able to pilot one of these Big Bird, even if I am not a real professional pilot.

— Zacarias Moussaoui, the alleged 20th hijacker, in a 2001 letter written to the Pan Am International flight academy. They guessed him to be a rich playboy, but when when they started training him they called the FBI. Reported (with his exact misspellings) by The New York Times, 8 February 2002.

I knew he wasn't real pilot material — he had actually studied his manuals and didn't talk about girls.

— Flight Instructor Clancy Prevost, regards his experience with Zacarias Moussaoui. Reported in 'Newsweek,' October 2002.

I did what I had to do, and you should be very proud of that. It is a great honour and you will see the result, and everyone will be celebrating.

— Ziad Jarrah, hijacker on United Airlines flight 93, in a letter to his girlfriend, Ayse Sengun, that was intercepted by U.S. authorities. In the letter he also said that he loved her very much. Dated 10 September 2001.

Either end your life while praying, seconds before your target, or make your last words: 'There is no God but God, Mohammad is His messenger.'

— translated from written instructions for Mohamed Atta, the terrorist at the controls of AA flight 11.

What do I tell the pilots to do?

— CNN commentator Barbara Olson, passenger on American Airlines flight 77, cell phone call to her husband Justice Department official Theodore Olson, 11 September 2001.

I see water and buildings ... Oh my God! Oh my God.

— Madeline Amy Sweeney, American Airlines Flight Attendant, end of her phone call to supervisor Michael Woodward describing the hijacking of AA flight 11. She provided many important details before the plane was crashed into the World Trade Center, 11 September 2001.

JFK KJFK 111430
111351Z 3507KT 10SM FEW010 SCT250 23/13 A3014 RMK A02
SLP205 FU FEW010 FU PLUME DSNT NW DRFTG SE T02280133

— JFK airport New York METAR weather report, early morning 11 September 2001.

There is a bomb on board, we are meeting their demands, we are heading back to the airport.

— thought to be terrorist Ziad Jarrah, Cleveland Center ATC picked up this announcement, that he meant to deliver over the airplane PA. 11 September 2001.

A group of us are going to do something.

— Thomas E. Burnett Jr., Thoratec Corporation senior vice president and passenger on United Airlines Flight 93, cell phone call to his wife, 11 September 2001.

We're going to rush the hijackers.

— Jeremy Glick, software executive and passenger on United flight 93, last reported words from his cell phone call, 11 September 2001.

Are you guys ready? Let's roll.

— Todd Beamer, Oracle software executive and passenger on United flight 93, last reported words from his cell phone call to Lisa Jefferson, a GTC telephone switchboard operator (he didn't want to worry his pregnant wife). They talked for 13 minutes, during which they discussed the hijacking and recited together the Lord's Prayer and Psalm 23 — 'Though I walk through the valley of the shadow of death, I will fear no evil; for Thou art with me; Thy rod and Thy staff they comfort me.' 11 September 2001.

They're coming.

— voice in Arabic, reportedly toward the to end of the United flight 93 CVR. 11 September 2001.

!FDC 1/9731 FDC SPECIAL NOTICE - DUE TO EXTRADORDINARY CIRCUMSTANCES AND FOR REASONS OF SAFETY. ATTENTION ALL AIRCRAFT OPERATORS, BY ORDER OF THE FEDERAL AVATION COMMAND CENTER, ALL AIRPORTS/AIRDROMES ARE NOT AUTHORIZED FOR LANDING AND TAKEOFF. ALL TRAFFIC INCLUDING AIRBORNE AIRCRAFT ARE ENCOURAGE TO LAND SHORTLY.

— first FDC special notice issued by the FAA on the morning of September 11, 2001, which grounded all U.S. flight operations until further notice after the simultaneous quadruple hijacking. Aviation was spelled incorrectly.

Anyone flying within 25 miles of the Washington TACAN is authorized to be shot down.

— Washington Approach ATC, radio broadcast to the combat air patrol forming over the U.S. capital. Personal accounts and reported in AW&ST 9 September 2002. Morning of 11 September 2001.

What's the sense of sending $2 million missiles to hit a $10 tent that's empty?

— President George W. Bush, Oval Office meeting, 13 September 2001.

Is it likely that an aircraft carrier or a cruise missile is going to find a person?

— US Defense Secretary Donald H Rumsfeld, regards questions on an air war to kill Osama bin Laden, 23 September 2001.

I know planes, but I don't know INS.

— Berton Beach, Vice President of Operations Aeroservice Aviation Center, Miami, (where 9-11 hijacker Ziad Jarrah studied) regards how Saddam Hussein's stepson Mohammad Saffi was able to enroll without the required student visa. July 2002.

If you want to travel on the airline system, you give up your privacy. If you want your privacy, don't fly. Flying is voluntary.

— Robert Crandall, former CEO American Airlines, April 2002.

The tolerance of the public is diminishing. We're spending time on the wrong people. It's nutty. There has to be a better way. Why are we stripsearching Aunt Molly from Iowa and letting on Richard Reid?

— Donald Carty, Chairman and CEO American Airlines, April 2002.

I never got a lot done using a broomstick. You've got to have something that's lethal.

— Montana Senator Conrad Burns, regards the U.S. Senate approving guns in cockpits. September 2002.

Will someone please explain to me the logic that says we can trust someone with a Boeing 747 in bad weather but not with a Glock 9 millimeter?

— Georgia Senator Zell Miller, during debate in the U.S. Senate regards approving guns in cockpits. September 2002.

I don't want to be on the list. I want to fly and see my grandma.

— Edward Allen, a four year-old boy and US citizen somehow placed on the TSA no-fly list four years after 9/11. Reported in 'USA Today' 10 January 2006.