Descriptions of Boeing 767, 757

Sept. 11 -- Here are overviews of the U.S. aircraft models apparently hijacked today, which may have been used in terror attacks.

Boeing 767

The Boeing 767, apparently hijacked in Boston and used in the attack on New York's World Trade Center, is among the most popular planes in the world. The 767 is a twin-engine, two-aisle jumbo jet first put into service 19 years ago. It can carry as many as 300 people and is flown by two pilots.

"It's extremely reliable," said ABCNEWS aviation expert John Nance, adding that there are as many as 70 in the air at once.

American Airlines today said Flight 11 was en route from Boston to Los Angeles carrying 81 passengers, nine flight attendants, and two pilots. According to the FBI it was one of the two planes to hit the twin towers.

United Airlines also lost a Boeing 767 today — Flight 175 was heading from Boston to Los Angeles with 56 passengers, two pilots and seven flight attendants. By early afternoon they had confirmed it crashed into the World Trade Center.

Boeing 757

Boeing's 757 is a single aisle plane capable of operating from a range of airports, including short-field runways, according to the Boeing Web site. The aircraft shares a common flight deck with the 767, which simplifies pilot training. It is used for both trans-Atlantic flights and short routes.

Two 757 planes are reported to have been involved today. American Airlines Flight 77 en route from DullesAirport near Washington to Los Angeles was carrying 58 passengers, four flightattendants and two pilots when it reportedly crashed into the Pentagon this morning.

United Airlines Flight 93, en route from Newark, N.J., to San Francisco, crashed about 80 miles southeast of Pittsburgh carrying 38 passengers, two pilots and five flight attendants.

American Airlines information line: 1-800-245-0999.

United Airlines information line: 1-800-932-8555.