The minimum age to obtain an Airline Transport Pilot certificate is 23, which means that it is possible that new airline pilots were as young as two years old when the attacks of September 11, 2001 occurred. The world changed forever on that day, and it's worth looking back at the airline industry before, during and after the attacks.
Although Secretary Rice stated that no one could have foreseen such an attack, in my Doctoral dissertation I documented 13 attempts to fly aircraft into buildings as terrorist attacks prior to the attack on the World Trade Center.
Prior to the attacks, the airline industry had a cavalier attitude toward hijackings. Instructions to pilots were to "comply".
After the attacks, flight crews were operating by the seat of their pants. Until the implementing of fortified cockpit doors, pilots improvised on securing cockpit doors. It was easier for inward-opening doors, but everyone was resourceful.
Finally, fortified doors were installed, but it was clear to everyone that secondary barriers were required, and they still have not been mandated. Ellen Saracini, widow of United Airlines pilot Victor Saracini, has been advocating for secondary barriers for over 20 years.
https://youtu.be/zV3iLanISlw
The Federal Flight Deck Officer Program allowed armed pilots to occupy airline cockpits.
As an interim measure, some pilots were armed with tasers.
In the past nine months, 81 known terrorists have been apprehended at the southern border.