DENVER (AP) _ About a dozen fighter jets scrambled to respond to simulated hijackings of two jets packed with military personnel pretending to be civilians.
Marine Maj. Mike Snyder, spokesman for North American Aerospace Defense Command, said the airborne portion of Tuesday's drill was a success but would not detail specifics. He hinted that the fighter pilots simulated shooting down the planes.
``For the exercise there was certainly a simulated response that might not be reflected in the aircraft landing,'' he said.
The drill was designed to improve coordination among American and Canadian agencies and was planned before the Sept. 11 terrorist attacks. Snyder said the events that day helped officials fine-tune the exercise, which involved more than 1,500 personnel from the Unites States and Canada.
One plane, a Delta Air Lines 757, took off from Salt Lake City and was headed to Elmendorf Air Force Base in Anchorage, Alaska. The other was a Navy C-9 airlifter, acting as another airliner. It traveled from Whidbey Island Naval Air Station at Oak Harbor, Wash., to Vancouver International Airport.
The planes took off around 7 a.m. and had landed by mid-afternoon and law enforcement officers on the ground began running through their own scenarios for dealing with the hijackers.
Such training exercises are held annually. Last year's exercise involved testing defenses against a cruise missile terrorist attack on the Florida Panhandle.
Since Sept. 11, NORAD has flown 22,000 sorties to watch the skies for hijackers and other threats, and fighter jets have responded more than 300 times when a plane raised suspicions _ in many cases because the aircraft was off course or did not identify itself.
``NORAD is very well-trained and exercised regarding this particular scenario,'' Snyder said.
Among the agencies involved in Tuesday's one-day exercise were the FBI, the Royal Canadian Mounted Police, the new Transportation Security Administration, the Federal Emergency Management Agency and the Federal Aviation Administration.