The crash of a B-1B bomber shortly after takeoff from Dyess Air Force Base in west Texas was the third in four years since B-1 aircraft began flying as the nation's first new long-range bomber in more than 25 years.

The four-engine $204 million jet crashed in a cow pasture Tuesday afternoon. All four crewmen were able to bail out before the plane went down.On Sept. 28, 1987, another Dyess-based B-1B crashed at a training range in Colorado when the jet, built by Rockwell International Corp., ran into a flock of birds at 600 feet. Three crewmen died.

Following that accident, the Air Force budgeted $40 million to make the B-1B less vulnerable to birds by adding deflectors near sensitive hydraulic equipment.

In August 1984, one of four prototype models designated B-1A crashed at Edwards Air Force Base, Calif., killing one man and injuring two.

The aircraft normally carries a crew of four, each with ejection seats.

The plane has often been criticized since President Reagan resurrected the B-1 program in 1981. President Carter had killed the program four years earlier.

Last month, the General Accounting Office, Congress' watchdog agency, released a study saying that because of maintenance problems, B-1Bs at Dyess were unable to fly 47 percent to 66 percent of the time because they undergo maintenance "a significant portion of the time."

In its response to the study the Air Force said it would not have enough experience with the aircraft until 1994 to consider the plane "mature."

The Air Force also has been criticized during the past two years because of problems developing the bomber's radar-jamming gear. However, the service insists the plane is still the best long-range bomber in the world.

The Air Force ordered 100 B-1Bs at a cost of $27 billion.

The swing-wing bomber is designed to fill the gap between the aging B-52 and the planned B-2 Stealth bomber, intended to evade detection by radar.

The B-1B has a maximum speed of about 1,000 mph and a range of more than 7,000 miles. It is smaller than the B-52 but capable of carrying more bombs. It already holds a number of world aviation speed records for a plane of its size.