Originally posted by harrytuttle
When the missile is first dropped from the aircraft backwards you have aerodynamic problems.

Secondly, as the missile engines begin to provide thrust in the opposite direction it's initially going, the missile will actually begin to slow down and stop before it begins to move towards it's target. In other words, it would drop like a rock and missiles that aren't moving can't be controlled.

So for a period of time this backwards firing missile would be totally out of control - so regaining control of it as it's thrust picks up in the rear facing direction would be a very difficult task to handle.

It would probably be easier to fire the missile facing forward and have it turn around in flight towards your target.

This makes sense... but what about when bullets are fired from tail gunners in a bomber? This is a slower example, but the bullets would be going in the opposite direction of the craft.

In a dogfight, fighters are flying relatively slower than say, intercepting another plane (in which case they would be going as fast as possible. Wouldn't this give a rear-facing missile better opportunity to launch?

The aerodynamic issues are a big reason you see "over-the-shoulder" launches as opposed to "backward" launches. The Python 5, AIM-9X and ASRAAM all have this capability to some degree (limited mostly by the sensors of the launching aircraft).

In regard to bullets being fired from a supersonic aircraft, the bullets travel faster than the speed of sound in the case of a .50 caliber bullet. Even if the aircraft can travel faster than the bullets can, the bullets are traveling that same speed as the aircraft that they are inside of to begin with. Any bullets fired forward from a supersonic aircraft are travelling at the speed of the plane, plus the speed added when they are fired from the gun.

If the aircraft were capable of overtaking bullets that were fired from it, multistage rockets also would not function, as the first stage would fly right through the second stage when the second stage tried to launch!

Originally posted by butcherguy
If the aircraft were capable of overtaking bullets that were fired from it, multistage rockets also would not function, as the first stage would fly right through the second stage when the second stage tried to launch!

So I do not know much about multistage rocketry, but if the rocket attains a certain velocity in say the first stage, the entire rocket with all its stages have attained that velocity and the ignition of a second stage would 'add' to the obtained velocity and all components affect by the second stage would be propelled at that total added velocity.
Or if the first stage exhausted its fuel and disconnected from the rocket, the rocket would coast at the achieved velocity and begin to decelerate due to gravity. The ignition of the second stage would help maintain the achieved velocity given to the rocket by the first stage.

Applying to same to gunfire from a bullet, wouldn't the bullet travel with an added velocity?
Well maybe one must consider (in the case of the rocket) the potential energy of the fuel in the second stage, being converted to energy thus reducing the mass of the propelled rocket and making calculations more interesting. I suppose the stability in trajectory of rockets depends on accurate calculations of rocket mass reduction due to propellant burn etc etc..

Its all very confusing and I'm sure a guy in high school would know more than me right now!!
Back to Physics 101!!

What about a rear mounted machine gun ?