What is the purpose of an after burner on a fighter jet?

Question

What is the purpose of an after burner on a fighter jet?

Answer 1

It's great for air shows too!! The F4 was the best Thunderbird, and maybe Blue Angel. Flying a rock like that wasn't a breeze like the F16 and F18.

I used to work F4D;s in Thailand and at Hill AFB. Way to go Jim!!!

Answer 2

The afterburner sprays fuel into the hot exhaust of a jet engine where it ignites causing an sharp increase in speed but at the cost of much greater fuel consumption.  Fighter aircraft until the F-22 came into service could only reach supersonic speeds by using the afterburner.  Because of the high fuel use pilots were limited to using afterburners only in short busts as in an emergency to gain advantage over an adversary.  The F-22 is capable of "super cruise".  The ability to go supersonic with power of the engine alone.  The F-22 has afterburners but they can be used less thus saving fuel and increasing the range of the aircraft.

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The only civilian aircraft to use afterburners was the supersonic Concorde.  Because the Concorde could not reach supersonic speeds without afterburners for long periods of time during it's flight and at takeoff the aircraft had a high rate of fuel consumption and shorter range than would have been needed for most international routes.  The Concorde barely had enough fuel for a transatlantic flight and would have required fuel stops if used on any other routes.  Concorde's take off run with full afterburners was very loud.

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Answer 3

Two purposes:  1- it allows one to carry a heavier weapons load and use a smaller runway; more thrust quickly means I can rotate even with a full loadout sooner.

2- In combat it allows one to accumulate any energy expended in maneuvering or pursuit.  

It works by directly injecting fuel into the exhaust; very much like having NO2 injectors in your car.  As others have stated, it REALLY consumes fuel; thus accelerating the "Joker" point (sufficient fuel to get home and still be able to disengage/maneuver) closer to present fuel status.  ( FYI, a significant number of USAF/USN kills in Vietnam were against MiGs that needed to disengage due to fuel issues)

BTW, the "super-cruise" feature of the F22, ain't working all that great.  As deployments to Japan and Alaska are proving...

Thanks, man.  D models-never flew one I was E's, and one tour in G's...great times.

Answer 4

Speed, at the expense of using a lot of fuel, but sometimes handy when you want to get away from the bad guys.

Answer 5

It's like kicking your car into passing gear. A burst of speed but you drink a lot of fuel