why don't airforces put backwards missiles on their planes? that way they can easily take down anyone who's behind them.

Their rocket exhaust as they're being fired would slow the planes down, rather than providing a boost

For the same reason, cars have exhaust on the rear so that they can go much faster forward than backward

Edit: /s since you apparently need it after every joke. I know that missiles aren't really fired, they detach and then propel themselves. Also, anyone who's ever idled their car on a flat surface knows that the exhaust thrust cannot even overcome rolling resistance.

Ackshually they do this, not with cars but, with WW2 era prop planes.
The Spitfire for example:
The Merlin consumed an enormous volume of air at full power (equivalent to the volume of a single-decker bus per minute), and with the exhaust gases exiting at 1,300 mph (2,100 km/h) it was realised that useful thrust could be gained simply by angling the gases backwards instead of venting sideways.
During tests, 70 pounds-force (310 N; 32 kgf) thrust at 300 mph (480 km/h), or roughly 70 hp (52 kW) was obtained, which increased the level maximum speed of the Spitfire by 10 mph (16 km/h) to 360 mph (580 km/h). The first versions of the ejector exhausts featured round outlets, while subsequent versions of the system used "fishtail" style outlets, which marginally increased thrust and reduced exhaust glare for night flying.
From Wikipedia
lol what?
Rockets aren’t attached to the plane when they launch. They release then fire there rockets. It might be near instantaneous but missile thrust has no bearing on an airplane.
The exhaust doesn't propel a car forward
- I'm going to start a meme crackpot theory.
  Torque doesn't exist.
  Cars move because of the exhaust gasses.
  "What about trucks with an exhaust that points up?" I hear you ask, well why are they always bent over at the top to point backwards?
  Tractors that have an exhaust on the top use it to keep the tractor on the ground, otherwise the forces of dragging things would cause the tractor to float off the ground. But the exhaust is pointed backwards slightly, other wise it wouldn't move. The small backwards pointing force explains why tractors are so slow.
  Electric cars are CGI, and part of the conspiracy to hide the fact that torque doesn't exist.
- Oh yeah dummy? Go plug up your exhaust and see if you drive anywhere.
- I forgot you need "/s" after every joke, even in joke communities. It is a reference to this greentext:
  Let's give anon the benefit of the doubt. Perhaps they're an alien engineer from a planet that only knows rockets, disguised as a teenager to learn about our modes of transportation.
  Yes, there is a short film with just about this plot
- Let's agree on that the effect is of negligible magnitude.
- Haven't you seen Batman?
The rockets would need to accelerate in the opposite direction of their initial motion, thus a lot more energy would be needed to reach design velocity. That makes it necessary to carry a lot more fuel for the propellant and thus, the rocket can carry less explosives. For some moment the rocket would also have zero velocity.
On the analogy with the car: The exhaust gases do not carry enough momentum to actually have a nonneglibile effect.
For the same reason, cars have exhaust on the rear so that they can go much faster forward than backward
Where do people come up with this nonsense
- It's a reference to the greentext I posted in another comment. I know it makes no sense.

There was a Clint Eastwood movie where backwards firing missiles were the whole shtick.

The catch is the plane is controlled by thoughts. Russian thoughts. The final dogfight came down to Clint finding his inner Russian and thinking of the magic word "blyat" to get the plane to fire ze backwards missiles.

It was a wild ride.

Given that summary I thought you were joking but holy shit that is an actual movie. crazy!
- What the actual fuck.
That's a fun movie
This movie seems horrible. I have to see it.

OP reinvents tail gunners

embrace tradition

It's obviously a great idea, but

(why has no one said this yet?)

Ackshually 🤓 - those things in the image of the A-4 that you flipped around are fuel tanks, not weapons.

Pretty sure those are Mark 14's.
- Mark 14 torpedos are straight in the middle, not curved all the way.
  Mark 14 torpedos have 4, not 2 fins at the end, and 2 screws.
  These are 300 gallon drop tanks. EDIT: now I'm wondering if the schematic shows the smaller Aero 1C 150 gallon drop tanks. Similar profile but thinner
  A-4 Skyhawks, like most fighter/attack jets since the 1960s, usually fly with at least one drop tank of fuel. The two tanks under the wings is the most used configuration during the 60s and early 70s. Later versions, such as the USMC's A-4M, which was used until the early 90s (but not deployed in Desert Shield / Desert Storm), were often seen with a larger drop tank (400 gallon?), often preferring a single large drop tank on the centerline to have more room for weapons. These did have a significantly stronger engine so bringing a larger payload was useful.

Missiles require an inordinate amount of thrust for their weight to remain airborne, due to the lack of large(ish) wings. Because the aircraft is already moving forward at high speed, the missile would lose considerable altitude (if fired backwards) before it would acquire sufficient velocity on it’s own again.

IIRC there have been missiles that could be targeted against aircraft behind the one launching the missiles. They would lock the missile against the pursuing aircraft, fire it forward, and the missile would arc around to go after the other aircraft.

Now bullets on the other hand, can come in supersonic versions. Unless the aircraft is moving at Mach speeds (and you always slow down to dogfight in order to make turns survivable), a supersonic bullet fired backwards will have sufficient speed in that direction to reach the other aircraft without too much aiming difficulties.

Beyond bullets: AFAIK there have been experiments in launching chaff (metal filings) such that it gets ingested into the pursuing aircraft’s engines, causing damage that way. But from what I recall there was too much of a risk of other aircraft in the vicinity and below that engagement also getting caught in the falling chaff. Still good for enemy aircraft, not so much for your own teammates.

Missiles would just have their initial attitude slightly upright - much like a javelin.

Fighter planes should just have a reverse gear. It would be much more simple.

Can't just drop it into reverse from like Mach 5 gear. Would need like a Mach 1 reverse, then speed back up to Mach 5 reverse
- I'll just leave the implementation details to you.
- We can't reverse. It's too dangerous. We have to slow down first!!
  Bullshit! Just reverse this thing! I order you! Reverse!
Bandit on your 6? Time for a bootlegger reverse maneuver.

Submarines used to have torpedo tubes in the back.

The original concept for a similar system was to have the pilot jettison multiple styrofoam mcdonalds containers out the rear of the aircraft, which would shred in the jet wash and gum up the enemy engine. A mockup of the system was performed along american highways in the 1970’s.

Unfortunately, future conditions made the system impractical, not due to a difficulty in finding styrofoam containers in america, but in getting the contract-required grimmace costume on the test pilots. The program was discontinued in 2018 due to budget reappropriating of funds for backup kuerig machines in all air force base quarters.

Hear me out.... Upgraded flight surfaces to account for lower launch speeds due to being backwards

It’s against the standards set down in Strunk and White’s Elements of Dogfighting

Which edition?

The missile would have to cancel out the speed of the plane before achieving any meaningful acceleration.

To be fair, speed is relative. Imagine a plane flies at 500 km/h and is pursued by another plane at the same speed. If the first plane fires a rocket backwards that accelerates for a total of 200 km/h, then for an observer on the ground the rocket will still do 300 km/h, in the same direction as the planes. However, the guys in the second plane will see a rocket approaching them at 200 km/h.
Wind resistance, aerodynamics, etc. will have an impact, but it can work.
- To be fair, speed is relative.
  Sure, but the relevant speed up there is relative to the air around you. The missile will have a negative air speed at first, than accelerate to positive, briefly passing through 0 in between, which comes with weird consequences for lift and steering.
Which would be meaningless. Those missile accelerate to like Mach 4 in a second.
A plane going forward at Mach 2 would add .5 second to a missile fired backwards to get to Mach 4.

Because you have to think in russian to fire them.

Why would anything be "behind" them?

It's called being chased at a dogfight.
- If you're in a dogfight then you're too close to use missiles effectively anyway.

Still makes me think of Extreme-G 2: Reah Fiyah Rockets.

mool tee pull miss aisle.

Regular forward facing missiles need to be "aimed" at enemy planes to be effective. How can you aim at something that is behind you?

Yo Ishmael! The boys at Mithridates University have come up with this sick new tech. The Romans won't know what hit them!
- Nerf please, our heavy infantry meta is no longer viable
Lmao I'm pretty sure the airforce could strap a rear facing camera on a plane
- So you want the driver of the plane to focus on two things? Unless you have another personnel manning that camera