How Tomahawk Missiles Reduce Infrared Signature
A Tomahawk's ability to minimize its heat signature comes down to its design and flight profile. Infrared sensors primarily detect the heat generated by an object, especially from its engine exhaust.
Key Design Features
• Low-Altitude Flight: Tomahawks fly very low to the ground, often just 50 to 100 feet above the surface. This tactic, known as "terrain hugging," helps the missile hide its heat signature against the "clutter" of background heat from the earth, buildings, and trees. For an IR sensor looking down, the missile's heat can blend in with the ground's thermal variations.
• Efficient Turbofan Engine: The missile uses a Williams F107 turbofan engine. Unlike the powerful, high-heat afterburning turbojets of fighter aircraft, this engine is a small, efficient powerplant designed for long range, not high speed. Its exhaust is significantly cooler and smaller, making it a less prominent IR target.
• Shielded Exhaust: The missile's engine and exhaust are located at the rear and are partially shielded by the airframe and tail fins. This design helps to mask the hottest parts of the missile from direct view, especially from the side or front.
• Subsonic Speed: The Tomahawk travels at subsonic speeds (around 550 mph or 880 km/h). This prevents the missile's skin from heating up significantly due to air friction, a phenomenon that can make faster, supersonic missiles much brighter to IR sensors.
Limitations of Evasion
Despite these features, a Tomahawk is still vulnerable to detection by advanced IR systems, especially from certain angles. A sensitive Infrared Search and Track (IRST) system on a modern fighter jet or a ground-based air defense system could potentially detect the missile's heat plume from the rear, particularly against a cold sky or ocean background. The goal of the missile's design is not to achieve complete invisibility, but to reduce the detection range and the time the enemy has to react.
