What type of planes were used in the 911 attacks?

Answer 1

The four planes used in the September 11, 2001 terrorist attacks were:

1. two Boeing 767 wide-body jetliners (American Airlines Flight 11 and United Airline flight 175)
2. two Boeing 757 narrow-body jetlines (American Airlines Flight 77 and United Airlines Flight 93)

The four hijacked planes could all be flown with the same training due to the commong "Boeing key", which made for much better coordination and easier training for al-Qa'ida. There does exist an important difference because a Boeing 757 carries only half as much jet fuel as a 767 and the attacks would certainly have turned out differently if 757s had been used against the Twin Towers and 767s against the Pentagon.