Hijackers Targeted Pentagon, Data Show
By Don Phillips
Washington Post Staff Writer
Friday, September 21, 2001; Page A10
The primary target of terrorists who hijacked an American Airlines flight from Dulles International Airport appears to have been the Pentagon, not the White House or Capitol, sources close to the investigation said yesterday.
Aviation officials have developed this theory after reviewing radar tapes showing that Flight 77 made a rapid, descending turn over Northern Virginia, nearly completing a full circle before it slammed into the Pentagon on Sept. 11, officials said.
The plane never approached restricted airspace around the White House or Capitol and turned off a course toward the White House when it was about 10 miles away, according to radar tracks of the aircraft's movements obtained by The Washington Post.
Vice President Cheney has said that Secret Service agents hustled him to the White House basement when they learned from the Federal Aviation Administration that Flight 77 "was headed on a track into" the executive mansion. Some members of Congress have also speculated that the White House or Capitol may have been targets of the attackers.
Although it may never be possible to determine what the terrorists intended, the track flown by the Boeing 757 indicates that the hijacker pilot intended to hit the Pentagon and did so skillfully, officials now believe.
"He made a nice coordinated turn," said one top aviation source, referring to a smoothly executed maneuver that would be made by a skilled pilot.
According to a radar track taken from a long-range radar installation at Dulles, the aircraft was headed due east, generally toward the White House, but began gradually turning toward the southeast more than 10 miles away from the restricted airspace that surrounds the White House. At that point the plane was headed directly toward the Pentagon.
The radar track shows that the 757 roared about 10 miles south of Dulles at 9:27:53 a.m., traveling at the unusually fast average speed of about 460 mph.
By then, the pilot had turned off the plane's transponder, which reports an aircraft's identity, speed, altitude and other information. While the FAA could determine the aircraft's average speed, it could not determine its altitude.
But investigators speculate that the pilot may have seen that he was too high to ram directly into the Pentagon from the northwest, and made a tight right-hand turn, losing altitude rapidly to approach the building from the west-southwest.
The final radar signal from the plane came at 9:37:35 a.m., about a mile from the Pentagon, when the plane dropped below radar level.
Radar tracks of the other three planes involved in the attack on New York and Washington show that all traveled at high speeds after they were hijacked -- 400 mph to 550 mph ground speed..
The track of United Flight 93, the Newark to San Francisco flight that crashed in Pennsylvania after passengers apparently tried to overpower hijackers and regain control of the plane, shows unusual altitude changes before the Boeing 757's transponder suddenly stopped working.
As it headed west at 35,000 feet, apparently in normal flight, the aircraft began climbing without authorization from air traffic controllers in the Cleveland "en-route center." Two minutes later, at 37,200 feet, the plane began making an unauthorized turn toward the southeast. Two minutes later it was at 40,700 feet. It descended to 39,700 feet before its transponder ceased functioning.
Investigators are puzzled about whether the altitude changes indicate a struggle in the cockpit between the hijackers and the crew, because it seems unlikely that the turn would have been smooth if there were a fight.