Air Force Museum
GBU-31/32 JDAM
JDAM converted ordinary free-fall bombs into precision weapons by adding an inertial/GPS guidance kit and movable tail surfaces. Because crews could program coordinates and release through clouds or darkness, the system expanded precision attack beyond laser-guided conditions. Its modular design also made large-scale precision capability less expensive than building an entirely new weapon.
In depth
History & service
Developed by Boeing for the U.S. Air Force and U.S. Navy, the Joint Direct Attack Munition (JDAM) guidance tail kit converts unguided, free-fall "dumb" bombs into accurate, all-weather "smart" Guided Bomb Units (GBU). These bombs cost much less than laser or television guided bombs. The tail section contains an inertial navigation system (INS) and global positioning system (GPS) guidance control unit.
It easily attaches to either a 2,000-pound BLU-109/-MK-84 bomb to make a GBU-31 or a 1,000-pound BLU-110/MK-83 to make a GBU-32. Target coordinates are located into the aircraft before takeoff; however, if the target moves, the aircrew can manually reset the new coordinates in flight, or onboard aircraft sensors can automatically update them. Once released, the fins guide the bomb as far as 15 miles to the designated target coordinates.
Details that tell the story
Joint Direct Attack Munition · Guidance combines inertial navigation and GPS updates · Tail kit can be fitted to several bomb bodies
Readiness became a permanent condition
During the Cold War, aviation was organized around the possibility of a conflict that governments hoped to prevent. Bombers, missiles, interceptors, reconnaissance aircraft, warning networks, and tankers became parts of interdependent systems. Their value was judged not only by what they could do in flight, but by how reliably they could be maintained, alerted, launched, supported, and controlled.
This emphasis produced striking aircraft and difficult tradeoffs. Long range demanded fuel and support. High speed increased heat and mechanical stress. Sophisticated electronics offered new capabilities but created new maintenance requirements. A reconnaissance aircraft needed an effective camera and a workable route as well as altitude or speed. An interceptor depended on warning and guidance before its pilot could make an engagement.
The human experience included long periods of training and routine punctuated by crises. Crews and ground personnel practiced procedures whose purpose was to remain credible without being used in war. At the same time, military aviation carried out reconnaissance, transport, rescue, humanitarian missions, and conventional operations around the world. Linking these aircraft with civil airliners, research machines, and spacecraft reveals a history of shared technologies and different purposes. The machines embody technical accomplishment, but also the enormous resources and sustained human effort required to keep a global force ready.
