BOMARC System Operation
The BOMARC system was designed to be integrated into the Air Defense Command (ADC) SAGE command system. Once a SAGE command center designated a target, a BOMARC could be in the air within 2 minutes of the launch order. (Later this lag time was reduced to 30 seconds.) Before launching, the missile's guidance system received preset commands for its initial flight. Launched vertically, BOMARC quickly rose to cruise altitude and received guidance from the SAGE center tracking the target. Receiving the target information from ADC's air search radar network, the SAGE center's AN/FSQ-7 system used this data to calculate the intercept geometry and command instructions that were subsequently transmitted to the missile from a ground-to-air transmitter site. Signals from the ground adjusted the missile's flight path, directed the missile when to climb or dive toward the target, and activated BOMARC's homing radar. This last event usually occurred when the missile was 10 miles from its intended target. Because both A and B models used information from their own radars to compute the final intercept solution, BOMARC marked the introduction of the world's first active homing surface-to-air missile (SAM) system. The B version carried a Westinghouse DPN-53 radar, which marked the first use of a production pulse-doppler system, which gave the missile a capability to seek out low-altitude targets.
In addition to having advanced homing radar, the B version also had greater range because the liquid-fueled booster was replaced with a solid-fuel booster. This more compact solid-fuel booster left more room for additional liquid-fuel storage capacity Once expended, the BOMARC B jettisoned the solid booster, which helped extend the missile's range. The solid booster also allowed for safer maintenance on the ground. (See McGuire AFB, New Jersey, for an accident description involving a BOMARC IM-99A.)
Using a proximity fuse, the missile had both nuclear and conventional warhead capability. For the conventional high-explosive warhead, a detonation within 70 feet of the target was considered a kill.