Register Free

Announcement

Collapse
No announcement yet.

The Dragon and the Cobra

Collapse
X
Collapse
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
  • Filter
  • Time
  • Show
Clear All
new posts
  • eagle
    Rank 5 Registered User

    The Dragon and the Cobra

    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
    Attached Files
    How can less be more? It's impossible. More is more.
    Yngwie Malmsteen
  • contrailjj
    Rank 5 Registered User

    #2
    First word out of my mouth when I saw that was Jee - susss!!! 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:
    Gentlemen, you can't fight in here, this is a war room!

    Comment

    • DTJJ
      Rank 5 Registered User

      #3
      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

      Comment

      • Vector1771
        Member

        #4
        Crazy wing planform on those Drakens, Sweedish hardware is innovative to say the least

        Comment

        • slipperysam
          mmmm.... donuts

          #5
          Very impressive...... just wondering... each time he seems to roll to the left just a little before pulling up....
          We are 100% SNAFU

          Comment

          • Hyperwarp
            Rank 5 Registered User

            #6
            TO: eagle, DTJJ

            Thanx a million for the videos!

            PS: Mr. SOC, now its your turn!
            Important Hyper Note: I am NOT an Aeronautical Engineer NOR an Aerospace Expert, etc, etc nor do I claim to be one.
            Regards,
            Hyper McStupid

            Comment

            • roberto_yeager
              Rank 5 Registered User

              #7
              OHOHOHOHO!!!!!!!!!!!!!!!!


              BESTIAL.


              1Saludo
              Revista Ejercitos, sometime She will back...

              Comment

              • Z1pp0
                Rank 5 Registered User

                #8
                Originally posted by eagle View Post
                ...
                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

                Originally posted by DTJJ View Post
                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". But I still love The Draken. It's one of my favorits. ...you know with a couple of dussin else

                /Dan
                Latencia Profecionalis

                Comment

                • Trident
                  Rank 5 Registered User

                  #9
                  Sweet! I never thought I'd get to see a video of this, and in decent quality too, thanks!
                  sigpic

                  Comment

                  • torpedo
                    Rank 5 Registered User

                    #10
                    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) ?

                    Comment

                    • eagle
                      Rank 5 Registered User

                      #11
                      Originally posted by slipperysam
                      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.

                      Originally posted by torpedo
                      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.
                      How can less be more? It's impossible. More is more.
                      Yngwie Malmsteen

                      Comment

                      • KKM57P
                        Rank 5 Registered User

                        #12
                        http://www.mach-flyg.com/utg80/80jas_uc.html

                        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.
                        What may sound like a fairy tale today may be tomorrow's reality.

                        Comment

                        • aurcov
                          Rank 5 Registered User

                          #13
                          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.

                          Comment

                          • franc
                            Rank 5 Registered User

                            #14
                            So, Cobra is nothing, even Draken can do it?!
                            Je pense, donc je suis.

                            Comment

                            • robban
                              Rank 5 Registered User

                              #15
                              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?

                              Comment

                              • Lightndattic
                                Rank 5 Registered User

                                #16
                                I didn't think delta wings had that much pitch authority.
                                Fly into heavy IADS with a great radar and sensor fusion, but no stealth, you will have complete situational awareness of the guy that kills you.

                                Comment

                                • Distiller
                                  Talent on Loan from God

                                  #17
                                  Originally posted by robban View Post

                                  ...

                                  How is it that the engine can cope with the amount of disturbed air during this "Cobra" maneuver?
                                  Idling.
                                  "Distiller ... arrogant, ruthless, and by all reports (including his own) utterly charming"

                                  Comment

                                  • Dr.Snufflebug
                                    Boggleboople snufflebug

                                    #18
                                    Originally posted by franc View Post
                                    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 ngelholm (F 10, Scania Air Force Wing). The most recent clips of these exercises involved FAF and AAF Draken pilots IIRC.

                                    Lieutenant Colonel Gte 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.
                                    Last edited by Dr.Snufflebug; 3rd January 2014, 18:25. Reason: Some erroneous numbers
                                    sigpic

                                    Comment

                                    • Boom
                                      Under a banyan tree

                                      #19
                                      very interesting info there snufflebug !
                                      HAL - one step ahead of IBM

                                      Comment

                                      • Dr.Snufflebug
                                        Boggleboople snufflebug

                                        #20
                                        Originally posted by Boom View Post
                                        very interesting info there snufflebug !
                                        You're welcome.
                                        sigpic

                                        Comment

                                        Unconfigured Ad Widget

                                        Collapse

                                         

                                        Working...
                                        X