Despite these daunting requirements, almost all major companies responded, including Rockwell, Northrop, McDonnell Douglas, Grumman, General Dynamics, Lockheed and Boeing. These contractors clearly perceived that in future years, this program might be the only game in town. As business and political pressures grew, some dropped out. Grumman retired from the program because it was busy with the F-14 and AFT programs, and Rockwell International pulled out because it was mired in troubles with the B-1B.
