In looking at European-designed fighters of the 4th and 4.5th generation, I keep seeing a common design feature; a box-like structure built into the tail, often in the top half or third. Some examples:

Saab Gripen

enter image description here

Mirage 2000 (this one's more complex and less box-like but the arrangement is very similar)

enter image description here


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Eurofighter Typhoon (this one looks markedly different, much lower and more like an intake)

enter image description here

Panavia Tornado (this one has two main protrusions from the tail, one much like the Typhoon's, the other more like the Gripens or Rafales)

enter image description here

SEPECAT Jaguar (you know what you're looking at by now)

enter image description here

What is this box? My best guess is some sort of avionics/sensor package, maybe RWR/missile warning. What's odd to me is that this box-in-tail arrangement is not seen on any relatively late-model U.S. or Soviet fighter; you'd think if the Europeans were onto something with this placement, the U.S. or Soviets would have tried it out at least once.

The F-15 has what I think is an RWR probe on top of the left tail, but the tail itself is pretty clean: enter image description here

The F-16 does have a boxy construction flaring out at the top of the tail, but the front is clean: enter image description here

The F/A-18 has some trailing-edge bulges but again very clean: enter image description here

Su-27, ditto to the F-18 (it does have that big probe between the engines though): enter image description here

MiG-29, same thing: enter image description here

I could go on but you get the point, Soviet and U.S fighters seem to have passed on whatever this package is in the tail. So, what is it, why is the arrangement limited to European fighters (for the most part) and how do other regional designers accomplish whatever these do?

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    $\begingroup$ Very good question Keith I couldn't even find the answer on google. I am guessing it is a radar warning system. I beleive that the f-16, 15, and 18 may have a different missile warning system. Thats probably why you don't see it on the other aircraft because they use a different system. Just a theory though. $\endgroup$
    – Ethan
    Commented Aug 28, 2015 at 0:44
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    $\begingroup$ Great question! Want to credit your pics? ;) $\endgroup$
    – FreeMan
    Commented Aug 28, 2015 at 12:43
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    $\begingroup$ I'm not sure it is a comparable device on all the aircrafts. The ones from the typhoon and the lower one on the tornado seems to differ by being equipped with an air intake $\endgroup$
    – Manu H
    Commented Aug 28, 2015 at 13:12

2 Answers 2


You're right. It's the ECM/EW antenna/equipment (fairing) in all the aircrafts except Typhoon.

This photo shows the details of EW/ECM suite in Gripen.


Source: www.w54.biz

In Typhoon, it is the engine bleed air heat exchanger. The part is in detail here.

Typhoon Heat exchanger

Source: b-domke.de


On the tornado the box at the top of the fin is the RHWR basically to warn the A/C if there is a radar locking on to them. The lower protuberance like the typhoon is an intercooler intake.


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