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    65000' is not low. The pressure recovery system is probably not as efficient as that of some other aircraft, and you have to feed a lot of air to a turbofan to keep it running.
    Of course, maybe in this case they wrote a script that turns the engine off at 65000' instead of making this dynamic, so who knows.
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      There is text in french somewhere of a high ranked AdA guys flying on a 2000D after a long time doing office work. It says that after "unvoluntarily" going too high he has to restart the engine in flight, so the engine stopping at high alt is probable to me .
      Helljumper - M2000C Guru

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      https://www.youtube.com/channel/UCK3...UxPbWHvJJ3W2fA

      Comment


        Originally posted by AeriaGloria View Post
        If we compare brochure climb rates, the Mirage 200C is superior, and high altitude climb is one of the many benefits of a tailless delta owing to low wing loading.

        So is their any specific documentation showing it should be slower climbing then F-15C or F-16C at those altitudes?

        Just based off brochure we get

        F-16C block 50: 250 m/s

        F-15C: 250 m/s

        Mirage 2000C: 295-300 m/s

        I would assume that a lot of that is due to high altitude performance, where the tailless delta wings higher wing loading loses less performance

        It's not so much the delta wing, it only determines the aircraft Critical Mach, but the combination of the engine and Multi-shock inlets works to the advantage of the Mirage in supersonic and at higher altitude.

        The one-shock inlet on the F-16 will experience a fall of pressure recovery resulting in a loss of thrust of up to 30% in supersonic compared to multi-shock inlet.

        Then there is the little matter of the M-53 being conceived from stock for M 2.5, with an original requirement for M 3.0, it was conceived and optimized for high mach/high altitude interception.

        In the 70s, the engine was successfully bench tested at M 2.5, M 3.0 was possible with minor changes in internal parts and materials regarded as "simple" modifications, some of which were applied to the P2 variant.

        At M 2.0, the Mirage 2000 will have to be throttle down to prevent it to accelerate, its Mach limit is Kinetic heating, not aerodynamic.

        When it comes to Aerodynamics, the 58* sweep angle of the Mirage 2000 delta provides it with a much higher Critical Mach than the F-16 40*.

        This means that transonic shock waves causing drag will start to appear at a higher Mach, Mach 1.0 will be reached with a lower drag ratio, and the drag curve will lower faster passed Mach 1.0.

        So to summarize: Less drag, less thrust loss in transonic and passed M 1.0 and better performances at high altitude than F-16, at low altitude however, and lower speed, the advantage is to the F-16 but not to the same extend, as the Mirage inlet experiences a lower loss of pressure recovery in subsonic than a one shock in supersonic.

        If anything, in DCS the Mirage 2000 is significantly nerfed, it can't even reach its Operational ceiling of 60,000 ft which btw is only imposed by the fact that there is no provision for pressure suits, not engine limitation (I had flame-out at 48.000ft).

        So its true flight envelop is compressed in terms of altitude and Max Mach at altitude in the way the F-16 doesn't experience in the game, this takes away one of the main advantages of the 2000, altitude and speed.

        The Mirage best climb rate is 60 000 ft/min
        https://www.dassault-aviation.com/en...t/mirage-2000/

        Sources:
        AIRCRAFT PERFORMANCEFLIGHT TESTING
        WAYNE M. OLSON Aircraft Performance Engineer TECHNICAL INFORMATION HANDBOOK
        SEPTEMBER 2000
        >>>

        COMAERO COMITE POUR L’HISTOIRE DE L’AERONAUTIQUE
        UN DEMI-SIÈCLE D’AÉRONAUTIQUE EN FRANCE
        LES MOTEURS
        Ouvrage coordonné par Michel Lasserre

        The Fighter Pilot Podcast
        084 - Mirage 2000
        https://www.youtube.com/watch?v=a_MCDFOeW1U



        ......
        Last edited by Thinder; 09-18-2020, 01:58 PM.
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        Comment


          Originally posted by myHelljumper View Post
          There is text in french somewhere of a high ranked AdA guys flying on a 2000D after a long time doing office work. It says that after "unvoluntarily" going too high he has to restart the engine in flight, so the engine stopping at high alt is probable to me .

          The 2000D had a fixed inlet cones setting and is not optimized for high altitude but the opposite, a 2000C, 5F or Mk2 would probably not experience an engine flame out at 65.000 ft, which is within the flight envelop of the M53 P2.


          Originally posted by myHelljumper View Post
          Are you sure about the T/W ratio of the 2000 ?

          From what I see on the Dassault aviation site (https://www.dassault-aviation.com/fr...s/mirage-2000/) this is not accurate.

          The "Masse de combat" (combat weight) is 9.5t and the max thrust is 98kN. If i try to do the math (https://en.wikipedia.org/wiki/Thrust-to-weight_ratio) the T/W ratio is 1.05.

          I understand that the combat weight is not full fuel, so if we take the wikipedia numbers for full internal fuel (11t) we get a T/W ratio of 0.9.

          That's a big difference right there....

          Edit: I see the T/W ratio on the English wikipedia page is at 0.7, and the gross weight is at 13t, I wonder what is the aircraft configuration for that weight... the engine thust is also different on the Dassault website, the French wiki page and the English wiki page

          Combat weight is computed with 2 X AAMs and 50% internal fuel, forget Wikipedia...
          https://www.scribd.com/document/3981...Flight-Testing




          ......
          Last edited by Thinder; 09-18-2020, 08:02 AM.
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          Comment


            The operational ceiling is limited to 50 000ft because of cockpit pressurization
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              Originally posted by jojo View Post
              The operational ceiling is limited to 50 000ft because of cockpit pressurization

              Salut Jojo. I gave the Dassault-Aviation data, but it is possible that AdlA have put a lower limit to theirs than the client's, in which case, it would be the Service Ceiling...


              Just a new from their site...


              Saint-Cloud, France, September 12, 2020 – Greece announced today its intention to acquire 18 Rafales to equip its air force.
              This announcement illustrates the strength of the partnership that has linked the Greek Air Force and Dassault Aviation for more than 45 years, and demonstrates the enduring strategic relationship between Greece and France.
              Greece ordered 40 Mirage F1 from Dassault Aviation in 1974, then 40 Mirage 2000 in 1985 and finally 15 Mirage 2000-5 in the year 2000; this latest contract also includes the modernization of 10 Mirage 2000 to the 2000-5 standard with a large contribution from Greek industry.
              https://www.dassault-aviation.com/en...nd-the-rafale/

              ......
              Last edited by Thinder; 09-18-2020, 01:49 PM.
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              Comment


                Hopefully the HAF will publish the Rafale Flight manual like for the F-16

                Last edited by Steph21; 09-18-2020, 03:26 PM.

                Comment


                  Same test, both aircraft 2790 lbs of fuel, starting altitude SL, speed at pull up to 90 deg 240 KTAS

                  End altitude:
                  F-16C = 22,600 feet
                  M2000 = 22,400 feet


                  Worthy of note, the M2000 decelerated very slowly in the vertical climb as speed dropped below 180 or so kts, where'as the F-16 decelerated rapidly from 180 kts down. In short the F-16 pulled away initially, but in the end the M2000 caught up. This indicates that the Mirage is not loosing anywhere near as much thrust with loss of speed as the F-16, which is odd and seems to suggest some issues with RAM effect.

                  Same was the case in the sustained turn rate testing at SL, where above ~330 ktas the F-16 had the advantage, but below that the Mirage got increasingly better:

                  M2000 clean (2791 lbs) vs F-16C clean (2793 lbs)

                  250 KTAS = 4.30 G vs 3.80 G
                  300 KTAS = 5.10 G vs 4.95 G
                  350 KTAS = 5.90 G vs 6.15 G
                  400 KTAS = 6.95 G vs 7.20 G
                  450 KTAS = 8.00 G vs 8.35 G
                  500 KTAS = 9.00 G vs 9.00 G

                  Comment


                    Originally posted by Hummingbird View Post
                    Same test, both aircraft 2790 lbs of fuel, starting altitude SL, speed at pull up to 90 deg 240 KTAS

                    End altitude:
                    F-16C = 22,600 feet
                    M2000 = 22,400 feet


                    Worthy of note, the M2000 decelerated very slowly in the vertical climb as speed dropped below 180 or so kts, where'as the F-16 decelerated rapidly from 180 kts down. In short the F-16 pulled away initially, but in the end the M2000 caught up. This indicates that the Mirage is not loosing anywhere near as much thrust with loss of speed as the F-16, which is odd and seems to suggest some issues with RAM effect.

                    Same was the case in the sustained turn rate testing at SL, where above ~330 ktas the F-16 had the advantage, but below that the Mirage got increasingly better:

                    M2000 clean (2791 lbs) vs F-16C clean (2793 lbs)

                    250 KTAS = 4.30 G vs 3.80 G
                    300 KTAS = 5.10 G vs 4.95 G
                    350 KTAS = 5.90 G vs 6.15 G
                    400 KTAS = 6.95 G vs 7.20 G
                    450 KTAS = 8.00 G vs 8.35 G
                    500 KTAS = 9.00 G vs 9.00 G

                    There is a campaign mission (No1) where you are tasked with testing the effects of the two FBW Gain switch settings, for CHARGE and A/A.

                    I tested the Mirage with focus on speed loss starting from aiming toward way point 4 at 15.000 ft and 500 kt.

                    In the CHARGE setting the A-C will not give you more than 6.0g/10* AoA but over a 360* turn will not loose more than 5/10kt, on the other hand A/A will give you 9.0G very rapidly but the A-C will bleed speed at a huge rate as early as it reaches 10* AoA + which is the maximum the A-C will give you in CHARGE setting.

                    This lead me to put an interesting tactic together for an Instant mission (Caucasus Missile Combat) in which you're pitted against 2 X Mig-23 and 2 X Mig-29.

                    I play it with all cheats ON including unlimited fuel and weapons since I'm training with the A-C and still learning it, I can keep going when I'm hit or correct mistakes with missile launch when I miss. FBW Gain switch stays at A/A setting.

                    From the start at 24.000 ft I go full A-B until I reach <> 400/425kt, I let the A-C accelerate while I'm setting it up for combat, (does turning the navigation lights off help with visibility of your A-C?), then pull gently on the stick with an eye on the AoA indicator, no more than 5* AoA, less than 2G.

                    Climb with velocity vector at <> 25* up to <> 350kt then roll over when the Missile warning goes off with an axis offset of <> 45/50* and nose down near vertical to gain speed.

                    This way I manage to dodge the AAM by geting out of its seeker cone and aim for my target after a gentle recovery at less than 3.0G at this point I am often at M 1.3/34.

                    Now this is where it becomes interesting, because the less you pull to acquire the target above you, the less energy you loose and below 5* AoA the Mirage loose little, I also stay under its nose to guide my AAM so my speed loss is minimal.

                    When I'm finished with the first target I often have enough energy to turn near vertical, acquire/lock and fire on the second Mig at altitude or even above it if I managed my energy properly.

                    That's between 350 and 250 kt depending on the emergency of the situation because my wingman is useless and the Mig is going to kill it fast if I don't get it.

                    You can repeat this with the two Mi-29 coming at you only this time they're on your back and you have the sun on your side. You can dodge the AAM with flares and climb straight into the sun on a gentle loop when you reached the desired energy level.

                    This way you can acquire/lock inverted with altitude to dodge more incoming AAMs. On a good day, I got all the kills with no hit against me and save my wingman who have been touring the whole mission.

                    All of this to say that pulling G with the Mirage is perhaps not always the best way to get into a fight, if you can get speed before the merge (central tank to use PC as long as possible?) and stay between 350 to 500 kt, you might well have more chances to win a fight.

                    Obviously I do not have the experience to be affirmative about the tactic but I am positive about the way to manage energy with the Mirage 2000C, stay below 5* AoA, 10* max, above that it's going to loose energy by the bucket.

                    Having said that, in theory, the best speed for best climb rate for the Mirage should be above 240kt, the faster the better due to the characteristics of the engine and inlets pressure recovery, in transonic it will always perform better.


                    About the inlet recovery factor, based on that of the F-15 compared to F-16. Considering the fact that the Mirage 2000 cones are similar to that of the F-15 in terms of shocks, we can safely assume similar figures in terms of pressure recovery. AIRCRAFT PERFORMANCE FLIGHT TESTING

                    The significance of Figure 6.2 is that for Mach numbers above approximately 1.6, the pressure losses become quite large (greater than 10 percent). The F-16 has a normal shock inlet and at speeds above 1.6; the actual inlet recovery is modeled quite accurately by the normal shock equation. The F-15, in contrast, has a series of inlet ramps, which turn the flow through oblique shocks as shown in Figure 6.3.

                    >>>>>>

                    The net effect of this oblique shock inlet is that at Mach number = 2.0, the inlet recovery factor is about 0.92 versus only 0.72 for the normal shock inlet. The downside is the increased complexity of the inlet producing an increase in aircraft weight. At subsonic speeds, the recovery factor of the F-15 oblique shock inlet is slightly less than that for the F-16. This is probably due to the losses in turning the flow.



                    Energy recovery after the first two kills, low G turn towards the sun.



                    ......
                    Last edited by Thinder; 09-19-2020, 10:52 AM.
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                      T:W ratios are not constants. They not only change as fuel burns, they also change with airspeed, especially in the Viper.
                      P-51D | Fw 190D-9 | Bf 109K-4 | Spitfire Mk IX | P-47D | WW2 assets pack | F-86 | Mig-15 | Mig-21 | Mirage 2000C | A-10C II | F-5E | F-16 | F/A-18 | Ka-50 | Combined Arms | FC3 | Nevada | Normandy | Straight of Hormuz | Syria

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                        Chatting with Mover about Fighter G Limits and Performance + Q&A



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                          Here you go :

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                            The problem is that currently the Mirage doesn't seem to lose thrust as speed decreases, whilst the F-16 does, indicating an error in modelling RAM effects. Hence why the Mirage is able to keep climbing straight up for longer (time) and sustain more G's below 330 KTAS than the F-16, which shouldn't be the case.

                            In short the Mirage is overperforming at low speeds atm, and it's due to thrust not decreasing with decreases in speed as it should.

                            Comment


                              Originally posted by Hummingbird View Post
                              The problem is that currently the Mirage doesn't seem to lose thrust as speed decreases, whilst the F-16 does, indicating an error in modelling RAM effects. Hence why the Mirage is able to keep climbing straight up for longer (time) and sustain more G's below 330 KTAS than the F-16, which shouldn't be the case.

                              In short the Mirage is overperforming at low speeds atm, and it's due to thrust not decreasing with decreases in speed as it should.
                              Why should „Thrust“ decrease ( at low speed )as speed decreases? Serious question , as it doesn’t make sense to me.
                              Usually with jet engines thrust increases with decreasing aircraft speed , at least in the low speed regime before ram effect comes into play.

                              Regards Snappy
                              Last edited by Snappy; 09-22-2020, 05:56 PM.

                              Comment


                                Originally posted by Snappy View Post
                                Why should „Thrust“ decrease ( at low speed )as speed decreases? Serious question , as it doesn’t make sense to me.
                                Usually with jet engines thrust increases with decreasing aircraft speed , at least in the low speed regime before ram effect comes into play.

                                Regards Snappy
                                You mentioned it yourself, ram effect. The faster you can cram air into the engine, the more thrust it produces.

                                Comment


                                  Originally posted by Hummingbird View Post
                                  The problem is that currently the Mirage doesn't seem to lose thrust as speed decreases, whilst the F-16 does, indicating an error in modelling RAM effects. Hence why the Mirage is able to keep climbing straight up for longer (time) and sustain more G's below 330 KTAS than the F-16, which shouldn't be the case.

                                  In short the Mirage is overperforming at low speeds atm, and it's due to thrust not decreasing with decreases in speed as it should.

                                  Are you sure you don't mistake thrust for 1G drag?

                                  Because at any speed where the Mirage can fly below 5* AoA, it will always drag less than the F-16, that's what the Delta wing tend to do, even if its effects are more sensible in transonic and supersonic, this is a fact.

                                  Compressibility take effect when shockwaves hits the airframe but the drag polar goes up long before this occurs and an airframe with a higher Critical Mach also have lower drag before it reaches the zone.

                                  Then, you all assume that the Mirage 2000 is under-powered, but at its designed combat weight, it is not, that would be 50% internal fuel and 2 X IR AAMs. = 1.05. Ask yourself what your F-16 Block 50/52 combat weight really is.



                                  As for RAM effect, same, it should also work in favor of the Mirage for the simple reason that the M53 is designed to take advantage of it but its raw thrust figure is static.

                                  There are 7 different articles for procedures in order to compute thrust on an aircraft in the Edward AFB handbook, one for Military and one for full A-B:






                                  A Turbofan coupled with a one shock inlet is more likely to be more sensitive to inlet temperature changes and assuming that Thrust is constant at all Mach values is false.

                                  So even if it looks like a less efficient design than the F-110-GE-129, the M-52 P2 still has its advantages over it, better pressure recovery and lower sensitivity to disturbed airflow (involving inlet temperatures).

                                  The M53 is less dependent on the quality of the airflow and the efficiency of the inlet even more so at high Mach/altitude where it will always show better characteristics than the F-110-GE-129.

                                  About TWR: GE gives the F-110-GE-129 for Thrust class: 29,000 lb/129 kN, 28,984 lb according to f-16.net data but the USAF gives a 27,000lb figure.


                                  Thrust-to-weight ratio is usually calculated at the same aircraft weights used for the wing loading parameter and with the static, uninstalled, sea level thrust of the engine
                                  In short, once the aircraft reaches the Air Force Test center, there is no question of testing the engine on a bench on those conditions, but on the aircraft itself.

                                  I'm pretty sure that the M53 P2 data is given as Installed data as it fits the 1.05 TWR at combat weight, and the engine was tested in pressurized benches simulating flying conditions.

                                  So here you have at least one possible explanation on why F-16 players think the Mirage 2000C is badly simulated in DCS but don't forget that it was originally destined for AdlA Squadrons.

                                  For this reason, I doubt very much that we have inherited from a flight envelop equal or superior to that of the real aircraft, best example is their respective climb rates in the game....

                                  F-110-GE-129 has more thrust but not on a wide area of its flight envelop, just to put things into perspectives, procedures for flight testing are common between IPNER and the US/UK flight test centers.


                                  Maximum climb rate computed at seal level for the F-15 is given by NASA for " is greater than 50,000 feet per minute", Dassault give the figure of 60 000 ft/min.


                                  Here NASA compare F-15 and F-16 at T.O weight.






                                  Now, try to explain to me how a DCS simulated F-16 Block 50/52 can out-climb a Mirage 2000 with a lower climb rate than a F-15C.



                                  ......
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                                  Mirage 2000C, F-15C, Mig-29, A4E.
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                                  So far so good...

                                  Comment


                                    Originally posted by Hummingbird View Post
                                    The problem is that currently the Mirage doesn't seem to lose thrust as speed decreases, whilst the F-16 does, indicating an error in modelling RAM effects. Hence why the Mirage is able to keep climbing straight up for longer (time) and sustain more G's below 330 KTAS than the F-16, which shouldn't be the case.

                                    In short the Mirage is overperforming at low speeds atm, and it's due to thrust not decreasing with decreases in speed as it should.

                                    Are you sure you don't mistake thrust for 1G drag?

                                    Because at any speed where the Mirage can fly below 5* AoA, it will always drag less than the F-16, that's what the Delta wing tend to do, even if its effects are more sensible in transonic and supersonic, this is a fact.

                                    Compressibility take effect when shockwaves hits the airframe but the drag polar goes up long before this occurs and an airframe with a higher Critical Mach also have lower drag before it reaches the zone.

                                    Then, you all assume that the Mirage 2000 is under-powered, but at its designed combat weight, it is not, that would be 50% internal fuel and 2 X IR AAMs. = 1.05. Ask yourself what your F-16 Block 50/52 combat weight really is.



                                    As for RAM effect, same, it should also work in favor of the Mirage for the simple reason that the M53 is designed to take advantage of it but its raw thrust figure is static.

                                    There are 7 different articles for procedures in order to compute thrust on an aircraft in the Edward AFB handbook, one for Military and one for full A-B:





                                    A Turbofan coupled with a one shock inlet is more likely to be more sensitive to inlet temperature changes and assuming that Thrust is constant at all Mach values is false, at low speed you won't get 29.000 lb of thrust on an F-16 Block 50/52.

                                    So even if it looks like a less efficient design than the F-110-GE-129, the M-52 P2 still has its advantages over it, better pressure recovery and lower sensitivity to disturbed airflow (involving inlet temperatures).

                                    The M53 is less dependent on the quality of the airflow and the efficiency of the inlet even more so at high Mach/altitude where it will always show better characteristics than the F-110-GE-129.

                                    About TWR: GE gives the F-110-GE-129 for Thrust class: 29,000 lb/129 kN, 28,984 lb according to f-16.net data but the USAF gives a 27,000lb figure.


                                    Thrust-to-weight ratio is usually calculated at the same aircraft weights used for the wing loading parameter and with the static, uninstalled, sea level thrust of the engine
                                    In short, once the aircraft reaches the Air Force Test center, there is no question of testing the engine on a bench on those conditions, but on the aircraft itself.

                                    I'm pretty sure that the M53 P2 data is given as Installed data as it fits the 1.05 TWR at combat weight, and the engine was tested in pressurized benches simulating flying conditions.

                                    So here you have at least one possible explanation on why F-16 players think the Mirage 2000C is badly simulated in DCS but don't forget that it was originally destined for AdlA Squadrons.

                                    For this reason, I doubt very much that we have inherited from a flight envelop equal or superior to that of the real aircraft, best example is their respective climb rates in the game....

                                    F-110-GE-129 has more thrust but not on a wide area of its flight envelop, just to put things into perspectives, procedures for flight testing are common between IPNER and the US/UK flight test centers.


                                    Maximum climb rate computed at seal level for the F-15 as given by NASA for "greater than 50,000 feet per minute", Dassault give the figure of 60 000 ft/min.


                                    Here NASA compare F-15 and F-16 at T.O weight.





                                    Now, try to explain to me how a DCS simulated F-16 Block 50/52 can out-climb a Mirage 2000 with a lower climb rate than a F-15C

                                    The problem of the Mirage 2000C is not that much thrust, in some condition it will still have as much or more than an F-16, but induced drag.



                                    ......
                                    Last edited by Thinder; 09-24-2020, 08:01 AM.
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                                    Comment


                                      Hummingbird don’t you think the moving inlet spike is helping it avoid thrust loss as speed decreases? Why couldn’t that be a factor?

                                      Comment


                                        Originally posted by AeriaGloria View Post
                                        Hummingbird don’t you think the moving inlet spike is helping it avoid thrust loss as speed decreases? Why couldn’t that be a factor?
                                        The moving shock cones are there for supersonic performance.
                                        As cost saving measure, the moving mechanism was eventually removed from Mirage 2000N and D, limiting these strike variants to around M1.4.

                                        But there are additional doors and scoops to improve air intake at high AoA.
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                                        Comment


                                          Originally posted by AeriaGloria View Post
                                          Hummingbird don’t you think the moving inlet spike is helping it avoid thrust loss as speed decreases? Why couldn’t that be a factor?

                                          It depends on the design of the inlet, on the F-15 there is a slight loss of pressure recovery "probably due to the losses in turning the flow".

                                          I don't have such details about the Mirage 2000 but never eared of such an issue, the D model has fixed inlets optimized for a lower Mach but as a thumb rule, the cones of the Mirage produce similar multiple shocks to the system of ramps used by the F-15.

                                          They are not designed for lower speed but higher Mach figures where the airflow must be slow enough to be recycled by the engine compressor.

                                          The engine own pressure recovery characteristics also matters a lot, turbofans tends to be more sensitive to pressure and temperature changes as well as airflow quality in the inlet than M53 is.

                                          The engine also has a natural tendency to increase its bypass ratio as Mach increases, the M53 P2 was modified to take advantage of that with a variable regulator, it becomes more efficient at high Mach.

                                          Overall, I'd say that an aircraft which has to be throttled down to prevent it to accelerate passed its Mach limit isn't under-powered.





                                          ......
                                          MSI B450 GAMING PLUS MAX AMD Ryzen B450 ATX DDR4 Motherboard, AMD Ryzen 5 3600X, EVGA NVIDIA GeForce GTX 1080 Ti 11GB, 32GB Kit DDR4-3200, 22' Samsung, Oculus Rift CV1. Thrustmaster T.16000M FCS HOTAS.
                                          Mirage 2000C, F-15C, Mig-29, A4E.
                                          Avatar: Escadron de Chasse 3/3 Ardennes.
                                          So far so good...

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