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Why do all new European fighter jets - Typhoon, Gripen, Rafale have delta wings? As I know, they were all designed separately. And they are not new either.

Is there any particular advantage that caused the Europeans to choose to do it like it is? Is it because of traditions? Or do they use the same software? (cheeky grin)

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  • $\begingroup$ The accepted answer to this question tells you why but by answering the reverse - why aren't deltas used? $\endgroup$ – Simon Feb 16 '16 at 20:54
  • $\begingroup$ Well, it is a nice answer, but I still don't know, why all European manufacturers choosed delta wings. $\endgroup$ – user3624251 Feb 16 '16 at 21:02
  • $\begingroup$ ...wait, you mean there are fighters that don't have delta wings? $\endgroup$ – Sean Apr 24 at 22:02
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No, they were not designed separately. They were designed by people who had all participated in collaborations before. The origin was the research into unstable configurations performed by MBB in Germany in the late 1970s by a modified F-104, the control configured vehicle F-104 CCV.

F-104 CCV

F-104 CCV (picture source)

As a result, MBB designed the Taktisches Kampfflugzeug 90 (or TKF-90), the first design of an unstable delta canard which promised unmatched maneuverability. Since Germany could not afford to develop the aircraft all by itself, collaborations were started with both Dassault and BAe, so that French and British engineers could learn of the advantages of this layout.

MBB TKF-90 concept

MBB TKF-90 concept (picture source)

First, BAe collaborated with MBB and joined the TKF-90 design, resulting in the European Collaborative Fighter proposal, only to continue on their own with two delta canard designs of their own, P.106 and P.110. P.106 had one engine and one vertical tail while P.110 had two of both, like the TKF-90. P.106 was rejected by the RAF, but went into a collaboration with Saab and eventually became the JAS-39.

To be fair, the first company to build and fly a closely-coupled delta canard was Saab with their Saab 37 Viggen. Saab has a long history of innovative work, beginning with ejection seats in 1942 and sweptback jets in 1948.

Saab 37 Viggen

Saab 37 Viggen (picture source). In contrast to the TKF-90 it was an aerodynamically stable layout.

Meanwhile, MBB collaborated with Dassault in the Future European Fighter Aircraft (FEFA) program, so the French side learned of the advantages of a delta canard. Eventually, the French wanted less air-to-air capabilities and a smaller aircraft for better export chances, and the remaining FEFA partners continued in the European Fighter Aircraft (EFA) program which resulted in the EF-2000, while Dassault went it alone with the Rafale.

The EF-2000 is hampered to this day by this heritage. Its wing area was decreed by Maggie Thatcher and Helmut Kohl to be no more than 50 m² when a 60 m² wing would had resulted in a much more capable design. Next, the British engineers insisted on a straight leading edge, ignorant of the fact that only a cranked delta would provide good post-stall pitch characteristics. They also refused to accept a faceted design, and the German side could only rescue the "smiling intake" in order to reduce the radar cross section of the EF-2000 somewhat.

"Smiling intake" of the EF-2000

"Smiling intake" of the EF-2000 (picture source). The curved contour avoids corner reflections of electromagnetic waves.

And don't get me started on the odd location of the airbrake: On the center fuselage where it is least effective at high angle of attack and will blanket the single vertical tail. Designed by a committee with too many British engineers.

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    $\begingroup$ The smiling intake also accepts small carry-on luggage, it seems. $\endgroup$ – FreeMan Feb 17 '16 at 14:43
  • $\begingroup$ I didn't expected such a thorough answer! I alway though that the Typhoon is a pure English design. I don't understand the 60 to 50 square meters. And were the MBB or some of its staff a continuation from the second world war period? The period you mention was 30 years after the war, I am just curious why germans where the sort of a leader in that time. $\endgroup$ – user3624251 Feb 17 '16 at 20:27
  • $\begingroup$ @user3624251: BAe is practically the only company marketing the EF-2000, I guess that is why you got the impression they made it. A bigger aircraft has more range and can carry a bigger radar (just two things that depend on size; there are more), and the 50 m² meant fewer and smaller systems could be added. The comments are insufficient to explain the cultural differences between European nations. $\endgroup$ – Peter Kämpf Feb 17 '16 at 21:41
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    $\begingroup$ @user3624251: Yes, they did. Watch this. Pay especially attention to the narrative of Roland Beamont at 19:42 into the report. Makes you shake your head at the arrogance and hubris of British government bureaucrats. $\endgroup$ – Peter Kämpf Feb 17 '16 at 22:39
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    $\begingroup$ @PeterKämpf, do you have a source for your statement about Thatcher and Kohl? The video linked in your comment does provide evidence of the UK government micromanaging the TSR-2 out of existence, but not of Thatcher and Kohl specifying the wing area of the Eurofighter Typhoon. N.B. I am not saying you are wrong, but it would be good to have a reliable source for your claim. $\endgroup$ – sampablokuper Mar 6 '17 at 14:25
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Delta vs conventional wing has a good answer on some of the benefits/drawbacks of the design.

European military aircraft designers tend to prefer delta designs, dating back to the original Mirage, and even the Avro Vulcan bomber, whose design was actually begun in WW2.

The other two major makers of military aircraft, the US and the USSR/Russia, don't tend to use delta wings. Rare exceptions were the hybrid delta with tail design of the MIG 21, the North American XB-70, and most recently, the Boeing X-32JSF entry, which was changed to a tail design late in the competition due to Navy requirements. The last operational delta fighter in the US inventory was the F106 interceptor.

Why do European military aircraft designers prefer the delta wing?

The nature of the potential conflict plays a role in military aircraft design. European military aircraft, certainly in the past, were designed for fast sprints over relatively short distances where the delta's supersonic characteristics are a benefit, as in a NATO/Warsaw Pact conflict in Germany.

Russian and American aircraft are designed with longer distance conflicts in mind, where a good deal of the flying is at high subsonic speed, and the lower drag of the conventional wing reducess the need for refueling while in transit.

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    $\begingroup$ There are several other rare exceptions: F16, F18, F102 and F106 (which even have the world "Delta" in their names), F4, F14 in wing swept configuration, F15 etc. Delta wings in US designs is very-very common mainly because one of the great granddaddy of delta wings, Alexander Lippisch, worked for the US after WW2 (the other great grandfather of delta wings is of course Kalinin) $\endgroup$ – slebetman Jul 3 '17 at 2:43

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