When an air to air missile is fired but misses the target does it simply impact into the ground or does it have a self destruct mechanism to limit friendly fire casualties?

Answer 1

It depends on the situation in which the weapon is fired, but in virtually all cases there is no self-destruct after the weapon is fired. The only exception would be a weapon test scenario, but even then the data is collected via telemetry, not from the weapon remains. Even if there were such a mechanism, the resulting impact from such a widespread shrapnel cloud would cause a lot more casualties on the ground than the small impact area of the missile itself should it miss its target. It's the same philosophy used regarding an aircraft's nose guns - the bullets don't self destruct if they miss.

A-A missiles don't really contain that much explosives anyway - at the speeds of today's aircraft during combat, it doesn't take much to damage or destroy an aircraft. Most are heat seeking, meaning they target engines, and jet engines can be destroyed by just sucking in a bird. Aerodynamic breakup does the rest. Usually the explosion you see in gun camera footage is the resulting explosion from the igniting jet fuel, not the missile itself.

It also needs to be viewed from the proper military context in terms of overall casualties. During any air operation, there are strict rules of engagement in all areas of operations, meaning that the pilot must have permission to shoot missiles if over certain areas. Those decisions aren't made lightly, and regard for surface casualties is always a factor. But if the situation requires a missile to be fired, it is usually in one of 2 scenarios:

1. The pilot is engaged in Air Combat Maneuvers (dogfighting) with another aircraft and is trying to save himself or his wingman, or other squadron pilots.

2. The pilot is trying to prevent an enemy aircraft from penetrating friendly airspace to deliver ordnance to military or civilian areas (bombers).

In each case, the ground damage that would be caused by a missile that didn't connect is insignificant compared to that which would be caused by either a destroyed aircraft or a successful bomb drop.

There really isn't a way to have a viable self-destruct anyway in a combat situation. A missile can't be designed to self-destruct at low altitude - an enemy plane evading one would simply need to head for the deck. A pilot engaged in ACM is going to be more focused on the current missile heading for his afterburner than the one he shot that didn't connect.

The point is that anytime a decision to fire a weapon is made, it is understood that there is going to be casualties in the air and on the ground. How many is the key.

For friendly aircraft, missiles use an onboard IFF (Identification Friend or Foe) that interrogates a target for a corresponding transponder signal to tell it if it's friendly or not.