The last time they had flown was in December of 2000. What was wrong with them, if anything?
The aircraft which was said to hit the Pentagon has no records of any flights in 2000 or 2001.
All flights must be recorded, and details about every flight every aircraft makes is to be reported each month to the DOT according to aviation law.
Evidently a man named Aidan Monaghan did a Freedom of Information Request to get each month's flight information for each 9/11 aircraft for each flight prior to 9/11.
He was sent a spreadsheet that reflects the information above, showing no flights in 2001 (prior to 9/11 I presume) for any of the aircraft involved.
The Airline Handbook, Chapter 4, on airline economics, points out that an aircraft flies segments like links in a chain:
Whatever arrangements an airline chooses to pursue, its capital needs require consistent profitability. Because airlines own large fleets of expensive aircraft that depreciate in value over time ... Contrary to popular myth, airlines do not cancel flights because they have too few passengers for the flight. The nature of scheduled service is such that aircraft move throughout an airline’s system during the course of each day. A flight cancellation at one airport, therefore, means the airline will be short an aircraft someplace else later in the day, and another flight will have to be canceled, rippling costs and foregone revenue across the network ... Selecting the right aircraft for the markets an airline wants to serve is vitally important to its financial success. As a result, the selection and purchase of new aircraft is usually directed by an airline’s top officials, although it involves personnel from many other divisions such as maintenance and engineering, finance, marketing and flight operations ...(Airline Handbook). Airlines need to have all their fleet that is in good condition working and producing cash flow. The margins are too close to get loose and inefficient and let a plane sit idle. They do not take aircraft off-line for nine months just to give them a rest.
There are substantial questions in this case where multiple airlines had aircraft off-line for months, then all of a sudden on the same day brought them back on-line, and all of them were suddenly lost with all aboard.
In several Dredd Blog posts, here, we explain that the official conspiracy theorists acknowledge some holes in their story which they attribute to government officials lying to them.
Who lied and what they lied about is what all of the controversy is founded upon.
UPDATE: Evidently this has caused a stir, and there is a frantic effort to find the missing flight information for these aircraft.
It would be nice to know what these aircraft were doing during 2001 wouldn't it?
Maybe the missing records will show up and end up explaining everything.
When that is completed I will update this post again.
UPDATE 2: On a similar note, professional pilots requested and received, via a FOIA request, the purported flight data from 9/11 American Airlines Flight 77 which was said to have crashed into the Pentagon on 9/11.
Professional pilots have concluded that the NTSB has not given them the flight data from a civilian aircraft "Flight 77", but flight data more likely from a military aircraft.