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I was looking for air brake pictures on different fighters, and then I saw a Tornado using afterburner and air brake at the same time! Air brake duty is to reduce speed, isn't it? So why would a fighter burn so much fuel to increase thrust and then use speed brakes simultaneously?

Afterburner and Air brake

enter image description here

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The first photo is from the Tornado Role Demonstration Team's display at RAF Leuchars in September 2012 (source).

That Sep '12 show or its preparation is on YouTube. Most of the instances of the air brakes as seen from the cockpit (looking behind) are followed by the swing-wing extending and the afterburner turning off (you can tell from the sound of the variable nozzle actuators).

While the photos are cool, I'd say it's just perfect timing before the pilot turned off the afterburner while slowing down.

enter image description here
Such example (above) can be seen after 7:40 in this video. Notice the wing position, and from the video notice the aforementioned sound once the wing is extended.

Another possible reason is slowing down for the spectators to see and hear the afterburner. That can also coincide with the fake bomb drop – a pyrotechnic wall of fire, the smoke of which can be seen in the first photo in the question (example below).

enter image description here
An RAF Tornado GR4 carries out a mock bombing run (BBC)

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Most jets with afterburner don’t have a fuel dumping system so when they need to reduce weight in a short time they use afterburner to attain a permissible landing weight. However using afterburner causes aircraft to go supersonic very quickly. So they use speed brakes to stay subsonic.

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    $\begingroup$ Hello Kolom, welcome to aviation.stackexchange.com. We are looking for answers that give a bit more background to the claim that is made, such as references or an explanation. Simple one liners are often not enough to cover the topic. $\endgroup$ – DeltaLima Sep 15 at 21:10
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    $\begingroup$ So you're saying its done for effect, to have the afterburner in operation while not going as fast as that would normally, say over an airshow. $\endgroup$ – Criggie Sep 16 at 9:31
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    $\begingroup$ Even if an afterburning jet has fuel dump capability, this is often rather slow and there may be environmental or airspace regulations prohibiting or limiting its use. In some aircraft, afterburner can get rid of fuel faster than the dump system, and using air brakes to manage speed is a practical strategy. We did this on the F-35 flight test program to save time during return-to-base, or to quickly achieve a target weight before a test run. $\endgroup$ – MikeB Sep 17 at 23:13
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While the pictures above are most likely a result of the reason posited by ymb1 (showing off max blast while staying subsonic for the crowd), using afterburner with speedbrakes to reduce weight is a known practice in the fighter community, in line with Kolom's answer. Even if an aircraft is equipped with a fuel dump system, environmental restrictions and standard operating procedures limit the altitude at which fuel may be dumped; if already below that floor, using afterburner with speedbrakes extended is a practical way to reduce landing weight. I don't have any specific sources to cite, just drawing on my experience as a naval aviator.

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  • $\begingroup$ In KSP I've had to use brakes as control surfaces when things go wrong. Is there any possibility this is poor man's thrust vectoring? Say, if you wanted to do a back-flip into a stall on a dime. $\endgroup$ – Mazura Sep 17 at 2:55
  • $\begingroup$ @Mazura: I'd guess that's unlikely; fighters have large control surfaces that give plenty of control authority even at low speed. Possibly if your elevators are damaged, and the speed brakes aren't at the centre of gravity or lift... If you wanted to perform a cobra maneuver you'd maybe have afterburners on (for thrust to hold up the plane's weight) and speed brakes on (for the speed-limiting effect, not extra control authority). But according to Wiki, you normally apply thrust part way through. $\endgroup$ – Peter Cordes Sep 17 at 3:30

protected by Ralph J Sep 17 at 16:17

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