Missile WEZ
Before a valid launch from a WEZ can be achieved, the missile must “see” the target.
Today’s technology provides two detection methods, temperature and radar tracking.
Temperature tracking occurs in missiles such as the AIM-9 Sidewinder by having a
seeker in the missiles’ nose track a hot emission from the target, such as engine exhaust.
Tracking can also occur by acquiring a radar lock onto the target. The radar lock can
come from on-board radar, which externally relays target information to the missile.
Some examples of these missiles are the U.S. AIM-7 Sparrow and the former Soviet AA-
10 Alamo. Finally, the missile itself can contain its own radar to achieve a solution, such
as the AIM-120 Advanced Medium Range Air-to-Air Missile. In summary, a
technologically complex series of events must occur for a missile to detect, track, and fire on a target, assuming a launch in a proper envelope. A single failure in a software or
hardware component will result in a missed opportunity.
Missile WEZs are drastically larger than a gun WEZ. In fact, you can be in a valid
WEZ at any aspect to the enemy, in front of, or behind, as long as you are pointing
towards the enemy. Maximum range can exceed 30 miles, while minimum range can be
inside a mile, depending on missile g-capability and arming time. If the enemy is not
maneuvering, a missile can be employed at closer ranges, almost competing with a gun.
If the enemy is turning, the minimum range expands because the missile must perform a
high-g turn in order to hit the target. Modern missiles can pull over 30 g’s, or turn with
over 30 times the force of gravity. This maneuverability is required at close ranges, so
missiles can perform tight turns, thereby completing an intercept of a fast moving target.
However this can be a severe limitation if the enemy has generated a high rate of turn. If
too high, the g-limited missile will not maintain track throughout the intercept.
The minimum range of missiles is a limiting factor, but is constantly improving with
missile software updates. Today’s technology features gimbaled rocket motors that can
turn the missile and apply thrust in the direction the missile needs to travel, not just
straight ahead as in most rocket motors.2 This drastic improvement in missile
maneuverability will most likely decrease the minimum range of missiles, but will never
have the minimum range of a gun due to maneuvering limitations, required arming time,
and the limitations of its warhead.
Lethal Radius
It also takes a certain amount of time for the missiles to arm. You do not want it to
arm immediately in case it detonates in front of your aircraft within range of its lethal radius. Lethal radius highlights a physical limitation inherent in today’s air-to-air
missiles. Each missile warhead has a certain distance declared, or lethal radius, in which
detonation of whatever killing mechanism it contains proves successful in destroying a
target. In some missiles, a direct hit is not needed if it contains a proximity fuze, meaning
the warhead will detonate if it is within a certain distance of the target.
The warheads used “...are typically blast-fragmentation types, incendiary or
explosive pellets, or expanding-rod types.” 3 The rods or pellets explode outward toward
the target and cut through hydraulic lines or the cockpit itself to destroy the aircraft or
pilot. The significance of lethal radius is that a missile must complete a highly complex
intercept relatively close to an enemy aircraft, and fuze properly, in order for the warhead
to detonate. Conversely, a bullet fired from a gun contains no warhead or proximity fuze.
It causes damage by impacting the target at a high rate of speed.
Gun Benefits
This chapter has reviewed modern air-to-air principles of BFM along with key
definitions. The aerodynamic limitations inherent in employing missiles at minimum
range makes the gun weapon system crucial for tomorrow’s combat arena. The gun is a
simple weapon system to employ and maintain. It cannot be degraded by enemy
electronic counter-measures or flare decoys which all help to degrade missile
performance. Another significant benefit of using a gun is that it isn’t reliant on the
aircraft’s radar system. Radar missiles must work in concert with the aircraft’s radar,
which is very susceptible to enemy aircraft maneuver and counter measures. Finally, the
gun provides additional firepower and can be fired from an exclusive WEZ.
Summary
The gun benefits will not disappear in the 21st Century. The gun provides a fighter
pilot an additional weapon that rarely malfunctions. By highlighting the inherent
limitations of modern missiles, the requirement to equip future fighters with a short-range
weapon should remain. As previously noted, the gun has been a constant in aerial
warfare. An examination of future implications and missions will help us decide if this
constant will remain.
