The Dragon and the Cobra

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24 years 2 months

Posts: 2,271

Its no F-22, Su-35 or MiG-29 OVT.
Just an old J-35 doing what i think is a cobra:
J 35C Flygning The video is from this site:
http://www.f10kamratforening.se/

Years after the retirement of Austrian Drakens I begin to understand its true capabilites. No wonder it wasnt retired until 2005 :D

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Member for

18 years 2 months

Posts: 1,085

First word out of my mouth when I saw that was Jee - susss!!! :eek: It sure looks like a 'Cobra' - even beyond the 90 degrees, although I'm sure the MiG and Su officianados will say it wasn't enough :diablo:

Member for

17 years 1 month

Posts: 64

Crazy wing planform on those Drakens, Sweedish hardware is innovative to say the least

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17 years 10 months

Posts: 784

Very impressive...... just wondering... each time he seems to roll to the left just a little before pulling up....

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20 years 2 months

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TO: eagle, DTJJ

Thanx a million for the videos!

PS: Mr. SOC, now its your turn! :p :o

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18 years 1 month

Posts: 949

OHOHOHOHO!!!!!!!!!!!!!!!!:eek:

BESTIAL.

1Saludo

Member for

18 years 5 months

Posts: 204

...
Just an old J-35 doing what i think is a cobra:
J 35C Flygning The video is from this site:
http://www.f10kamratforening.se/

Years after the retirement of Austrian Drakens I begin to understand its true capabilites. No wonder it wasnt retired until 2005 :D

Excellent stuff - I believe it was done quite regularly by the SK 35s, but not at low altitude!

Here's an interesting clip of a superstalling Draken.

http://www.ntps.edu/HTML/Video/Videos/Superstall.htm

Just as DTJJ mentioned: Superstall is not a new phenomenon to Deltawinged aircraft, and this was done as a training exercise for the Draken pilots. IMO this is not a "Cobra manouver". :cool: But I still love The Draken. It's one of my favorits. ...you know with a couple of dussin else:D

/Dan

Sweet! I never thought I'd get to see a video of this, and in decent quality too, thanks!

Member for

24 years 2 months

Posts: 327

Cool !!
Does it mean that aircrafts like the Mirage III or the F106 would also be able to do that ?
Or what is special in the Draken (aerodynamic, engine, air duct) ?

Member for

24 years 2 months

Posts: 2,271

Very impressive...... just wondering... each time he seems to roll to the left just a little before pulling up....

Probably to avoid crashing into his wingman in case something goes wrong. Like in the nice video DTJJ has posted.

Cool !!
Does it mean that aircrafts like the Mirage III or the F106 would also be able to do that ?
Or what is special in the Draken (aerodynamic, engine, air duct) ?

I dont know about the F-106, but I think the Mirage 3 can do it. Must be somewhere on this forum. :)

Member for

18 years

Posts: 665

http://www.mach-flyg.com/utg80/80jas_uc.html
http://www.mach-flyg.com/utg80/bilder/fullsize/80jas3.gif
High angle of attack

„As remarked previously, the only externally visible “fix” to the airframe are a pair of small strakes behind the canard surfaces. This type of “flow augmentation system”, often serving the purpose of directional and lateral stability enhancement at high AOA, is not uncommon on fighters; suffice to mention the Eurofighter and the Mirage 2000.“

Saab Gripen
„In the high AOA and spin tests that has taken place since 1996 and recently concluded successfully, the normal tactic was to initiate the tests with a near vertical climb with speed dropping off to near zero and a rapid increase of AOA up to extreme angles, and the aircraft could then be “parked” at 70 to 80 degrees of alpha. When giving adverse aileron input there, a flat spin with up to a maximum of 90 degrees per second of yaw rotation started and could then be stopped by pro aileron input. Recovery followed, whenever commanded.“

Member for

18 years 4 months

Posts: 1,366

Very impressive...... just wondering... each time he seems to roll to the left just a little before pulling up....
That's what I noticed too, when I took a second look to the video!
Probably to avoid crashing into his wingman in case something goes wrong.
Nope, they are not so close.

Somehow it's like an athlete flexing the legs before a jump -- it seems that with this little roll (before the abrupt pitch) they gain momentum.

Anyway it's impressive.

Member for

18 years 3 months

Posts: 620

So, Cobra is nothing, even Draken can do it?!

Member for

18 years 5 months

Posts: 448

If one would fit the Draken with a HMS, and the IRIS-T, it would be able to make use of the maneuver. But the missiles avaliable when the Draken saw service, seriously lacked the needed performance.

One of the reasons why the Draken could perform such a manouver is probably because of the dubble delta wing. A powerful vortice is created at the crank increasing lift. The Drakens instantaneous turn rate is reported to be quite good, while sustained turn rate is ~12 deg/sec at low altitude with 50% fuel.

How is it that the engine can cope with the amount of disturbed air during this "Cobra" maneuver?

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19 years 7 months

Posts: 400

I didn't think delta wings had that much pitch authority.

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20 years 5 months

Posts: 4,674

...

How is it that the engine can cope with the amount of disturbed air during this "Cobra" maneuver?

Idling.

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11 years 7 months

Posts: 479

So, Cobra is nothing, even Draken can do it?!

What Draken is doing is not a Cobra at all. It is an example of a serious drawback to the high aspect ratio, high sweep compound delta, ie. its tendency to go into an uncontrollable deep stall/superstall if the airflow was sufficiently disturbed.

All it took was a quick jolt in the roll axis at a moderate AoA (as you can see clearly in the footage) and the entire aircraft would pitch up violently and eventually enter an irrecoverable spin toward terra firma if the pilot did not react quickly enough with precisely the right control input before the machine passed the spin threshold. This inherent design issue was well known, it killed a whole bunch of pilots and ruined many more airframes, but it was kept largely under wraps for the time being due to the negative publicity it would have caused. Being a highly novel design, the developers knew that they took some serious risks and they had to persuade the government and the public opinion that taking such risks were worth it to stay in the game and produce a competitive aircraft. The same thing applied to the oftentimes overwhelming teething issues present in the earlier J 29 and the later AJ/JA 37 and JAS 39 (the A 32 was less controversial I think). There was a lot of negative press about them all in Sweden and both SAAB and the Air Force constantly had to defend themselves.

At the end of the 1960's the Swedish Air Force decided to address it by commissioning four trainer Drakens (Sk 35C) modified with anti-spin chutes and additional wing fences in the role of letting pilots familiarise themselves with this problem and learn how to recover from it should it occur.

All videos are from these exercises, which began in 1969 and continued for a long time (basically for as long as the Draken remained in active service). Typically the modified Sk 35C would be piloted by the student, with an experienced test pilot in the 2nd seat. Even with the spin recovery chutes and airframe modifications, it was a bit sweaty and the exercises were carried out at 35-38,000 feet or more for additional safety as you still needed quite a margin for recovery should things go even a tiny bit wrong.

With enough training, the pilot could however recover from it fairly swiftly, which is what we are seeing in these vids. But do keep in mind that it was a dangerous and essentially uncontrollable "maneuver", and it led to quite a few disasters over Drakens service years. I've heard from people involved that these exercises definitely weren't something the pilots looked forward to...

Foreign Draken operators were also keen on putting their pilots through this superstall familiarisation programme, which was carried out at the former Swedish AF base in Ängelholm (F 10, Scania Air Force Wing). The most recent clips of these exercises involved FAF and AAF Draken pilots IIRC.

Lieutenant Colonel Göte Marcusson did a series of interesting presentations on this particular SweAF episode a few years ago. He worked on the superstall problem for a long time, starting with the 1950's-early 60's test flights. He later became one of the supervisors of the subsequent trainer program.

As far as the engine airflow goes, I think they had to be kept at idle over the course of the stall and recovery, or another heap of problems would arise.

EDIT: I see that it has been cleared already. Well, glad to provide additional info at least. :)

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13 years 11 months

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very interesting info there snufflebug !

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11 years 7 months

Posts: 479

very interesting info there snufflebug !

You're welcome. :)