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    #81
    Originally posted by FBW View Post
    Point stands, look back at DI discussions, all sorts of load outs were compared. Anyway, instead of looking at the most common load outs for actual combat aircraft usage, most want to compare intercept configurations. Not very realistic.
    Many countries don't do much beyond intercept missions. I briefly remember that some Gripen users don't even have A-G modes installed, for example.

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      #82
      Originally posted by MSphere View Post
      Many countries don't do much beyond intercept missions. I briefly remember that some Gripen users don't even have A-G modes installed, for example.
      True, they are those nations unlikely to see combat as well. The last 30 years has shown that most aircraft flying in harms way are not loaded with 4 aams. Look at the typhoons that have been scrambled to intercept Russian bears, they are not flying clean in any sense of the word.

      Yet I agree with the premise of your post, for a nation like Switzerland, which is extremely unlikely to ever fly combat fighters in anything other than a short, fast air policing mission, the Gripen on a cost basis makes perfect sense. Sadly, the voters disagreed.

      Comment


        #83
        Originally posted by FBW View Post
        True, they are those nations unlikely to see combat as well. The last 30 years has shown that most aircraft flying in harms way are not loaded with 4 aams. Look at the typhoons that have been scrambled to intercept Russian bears, they are not flying clean in any sense of the word.
        Actually, NATO's QRA jets fly with 4 AAMs quite often, 6-8 in some cases. The RAF likes to fly with 8 AAMs it seems.
        If you're thinking about tanks, those can be dropped should the need arise. So yes, in an air to air scenario, and that's not just interceptions, you need to compare flight performance with 6-8 missiles.
        How can less be more? It's impossible. More is more.
        Yngwie Malmsteen

        Comment


          #84
          Here a Hellenic Mirage 2000-5EG Mk2 and French Rafale C armed on QRA duty - 2x ARH MICA, 2x IR guided MICA, one drop tank (to be jettisoned).
          I have serious doubts the max speed or acceleration after climb is imparted by this loadout in any significant way.


          Last edited by MSphere; 4th April 2015, 00:31.

          Comment


            #85
            Originally posted by eagle View Post
            Actually, NATO's QRA jets fly with 4 AAMs quite often, 6-8 in some cases. The RAF likes to fly with 8 AAMs it seems.
            Sounds about right

            Comment


              #86
              Originally posted by MSphere View Post
              Here a Hellenic Mirage 2000-5EG Mk2 and French Rafale C armed on QRA duty - 2x ARH MICA, 2x IR guided MICA, one drop tank (to be jettisoned).
              I have serious doubts the max speed or acceleration after climb is imparted by this loadout in any significant way.



              In terms of acceleration, the impact is not negligible:
              For an F-15E with the -229 engines, with a massive static T/W ratio at 45,000lbs of 1.296 here are the numbers clean and with 4 aam:

              10,000 feet clean mach .8 to mach 1.2: under 16 seconds
              10,000 feet with four aam: 17 seconds- not much difference

              40,000 feet clean: 40 seconds
              40,000 feet with 4 aam 45 seconds
              a 12.5% decrease in acceleration

              max speed difference is negligible for the F-15 because it is time limited but roughly .1 mach.

              For the F-16C which is much lighter fighter, at a gross weight of 24,000lbs ( which means it is low on fuel because the aircraft actually weighs 20,000lbs+ (not 19,000lbs as often quoted) with pilot and all lubricants and unusable fuel etc, it will touch mach 1.95 clean.
              With a DI of 50, reasonable if not low for 4 aam and pylons it's under mach 1.8

              The acceleration also takes a hit:
              at 10,000 feet 24,000lbs clean mach .8 to mach 1.23 takes 24 seconds
              at 10,000 feet 24,DI of 50 mach .8 to mach 1.23 takes 39 seconds

              clean at 40,000 feet mach .82 to mach 1.24 takes 61 seconds
              with a DI of 50 mach .82 to mach 1.24 takes 77 seconds

              Saying that 4 missiles and the associated pylons does not have an impact on acceleration is obviously wrong. Top speed is a little deceptive since both of the fighters are time limited on fuel so top speed is hypothetical anyway, the F-15E will not go above much above mach 2.3 clean or with missiles as it runs out of fuel (and the four aams are semi recessed so very little drag there). The F-16 looses about .15 mach with a DI of 50 ( the F-16 is also listed as a mach 2 fighter but the flight manual tops it out below mach 2, so I don't know)

              The point is: a smaller fighter is impacted by even the addition of pylons and missiles. The F-15E comes off better because the drag impacts it less, and frankly 4 semi-recessed missiles are not going to add a ton of drag (good news for the Typhoon).

              Edit- The DI 50 is the lowest listed, for a reason. Yes, the F-16 with two pylons+ missiles and two wingtip missiles can have a DI around 20, but how often does any air force remove all the other weapon pylons to clean the aircraft off? The DI of 50 about as low as they are going to fly with weapons.
              Last edited by FBW; 4th April 2015, 05:29.

              Comment


                #87
                Originally posted by FBW
                Yes, the F-16 with two pylons+ missiles and two wingtip missiles can have a DI around 20, but how often does any air force remove all the other weapon pylons to clean the aircraft off?
                looks like 2+2 AAM is the most common loadout after all
                Last edited by obligatory; 4th April 2015, 12:07.

                Comment


                  #88
                  Originally posted by obligatory View Post
                  looks like 2+2 AAM is the most common loadout after all
                  Seriously ignorant comment, do better. The point was it's the LOWEST DI from the flight manual on the F-16C. They go: DI 0, 50, 150, 200 as a point of comparison.

                  So no, it is not, its just the lowest listed. If that's the only comment you could make about my post, you completey missed the point.

                  Comment


                    #89
                    That would make the lowest drag index listed zero, wouldn't it.
                    Steps of 50 doesn't mean less than 50 is impossible. Data for some drag indexes is provided, you have to interpolate for the exact drag index of your configuration.

                    btw, drag index with 4 AAMs and centerline pylon is 36. That is a realistic loadout.
                    6 AAMs or 4 AAMs with centerline tank is 51, so yes, 50 happens to be a good reference point too.
                    Last edited by eagle; 4th April 2015, 17:48.
                    How can less be more? It's impossible. More is more.
                    Yngwie Malmsteen

                    Comment


                      #90
                      Originally posted by Vnomad View Post
                      Well they're fortunate that Egyptian military junta decided to splurge on arms during an economic crunch, else that 'strategic decision' might have landed Dassault Aviation with the first clean-sheet design to fail to get a single export order. As it is, production has been squeezed down to a trickle to make the annual intake affordable to the French state. With the basic French fighter industry wrapping up by 2020 or so (though allied segments will persevere, similar to Israel), closely followed by the remainder of the European industry by 2023 (when the Gripen E transits out of production), the question of how justified that decision to preserve 'national capabilities' was, may have a disheartening answer.
                      Actually Egypt is not in economic crunch as far as Rafale purchase is concerned. why they only order 24 that's more relevant. if it so advanced and without restriction they should build airforce around Rafale. You wont find biggest supporter of arabs than france.
                      EF is also not doing better only 44 delivered to RSAF in 8 years.

                      Comment


                        #91
                        Originally posted by FBW View Post
                        . They go: DI 0, 50, 150, 200 as a point of comparison.
                        @Eagle, read the above again a starting point DI of 0 would be a clean airframe. Also, read the note at the bottom of first post. I'm well aware that you can add up the various drag numbers from the stores list. There are, however, no acceleration numbers for those. DI of 50 is a good starting point as you calculated yourself for an aircraft with centerline and wing pylons with 4 aams.

                        Comment


                          #92
                          Originally posted by FBW View Post
                          In terms of acceleration, the impact is not negligible:
                          For an F-15E with the -229 engines, with a massive static T/W ratio at 45,000lbs of 1.296 here are the numbers clean and with 4 aam:

                          10,000 feet clean mach .8 to mach 1.2: under 16 seconds
                          10,000 feet with four aam: 17 seconds- not much difference

                          40,000 feet clean: 40 seconds
                          40,000 feet with 4 aam 45 seconds
                          a 12.5% decrease in acceleration

                          max speed difference is negligible for the F-15 because it is time limited but roughly .1 mach.

                          For the F-16C which is much lighter fighter, at a gross weight of 24,000lbs ( which means it is low on fuel because the aircraft actually weighs 20,000lbs+ (not 19,000lbs as often quoted) with pilot and all lubricants and unusable fuel etc, it will touch mach 1.95 clean.
                          With a DI of 50, reasonable if not low for 4 aam and pylons it's under mach 1.8

                          The acceleration also takes a hit:
                          at 10,000 feet 24,000lbs clean mach .8 to mach 1.23 takes 24 seconds
                          at 10,000 feet 24,DI of 50 mach .8 to mach 1.23 takes 39 seconds

                          clean at 40,000 feet mach .82 to mach 1.24 takes 61 seconds
                          with a DI of 50 mach .82 to mach 1.24 takes 77 seconds

                          Saying that 4 missiles and the associated pylons does not have an impact on acceleration is obviously wrong. Top speed is a little deceptive since both of the fighters are time limited on fuel so top speed is hypothetical anyway, the F-15E will not go above much above mach 2.3 clean or with missiles as it runs out of fuel (and the four aams are semi recessed so very little drag there). The F-16 looses about .15 mach with a DI of 50 ( the F-16 is also listed as a mach 2 fighter but the flight manual tops it out below mach 2, so I don't know)

                          The point is: a smaller fighter is impacted by even the addition of pylons and missiles. The F-15E comes off better because the drag impacts it less, and frankly 4 semi-recessed missiles are not going to add a ton of drag (good news for the Typhoon).

                          Edit- The DI 50 is the lowest listed, for a reason. Yes, the F-16 with two pylons+ missiles and two wingtip missiles can have a DI around 20, but how often does any air force remove all the other weapon pylons to clean the aircraft off? The DI of 50 about as low as they are going to fly with weapons.
                          The point of the above seems to have been missed, carrying weapons and pylons has an impact. An impact that is greater on a smaller fighter.

                          We can parse various DI configurations all day: two wingtip aam or two wingtip and aam on wings with pylons and adapters, or whatever. Even in the QRA pictures, the aircraft are carrying five pylons. Even when empty most will carry a min of centerline and four wing pylons. Most of the time the pylons stay on no?
                          Last edited by FBW; 4th April 2015, 18:07.

                          Comment


                            #93
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                            It seems we need to revisit these every month or so.

                            If we took the same simplistic approach someone on this board did recently we would simply look at the stat sheet, see that the F-18C and Super Hornet's max speed is M1.8. They are therefor just as fast as each other. They are also both faster than the M1.6 F-35.

                            Of course the reality is somewhat more complicated. With the same loadout the F-18C is marginally faster than the Super Hornet, and in a realistic air policing loadout with 4-6 AAM and at least one drop tank the F-35 will be significantly faster than either of them.

                            Comment


                              #94
                              Originally posted by FBW View Post
                              @Eagle, read the above again a starting point DI of 0 would be a clean airframe. Also, read the note at the bottom of first post. I'm well aware that you can add up the various drag numbers from the stores list. There are, however, no acceleration numbers for those. DI of 50 is a good starting point as you calculated yourself for an aircraft with centerline and wing pylons with 4 aams.
                              Actually, a clean F-16C airframe has a drag index of 7
                              I agree that DI 50 is a good starting point. Less than that is also possible, though unlikely in a real loadout. So at DI 50, top speed is Mach 1.85 vs 1.6 for the F-35. That, imho, is a valid comparison. Now, since the F-35 is not thrust/drag limited at Mach 1.6, it will still have some reserves at that speed. The question is: more than the F-16 at Mach 1.6? I think not, I bet an F-16C @ DI 50 will out accelerate an F-35 from lets say M 0.8 to M 1.6.
                              It takes an F-16C-52 ~110 seconds @ 30.000 feet, the F-16C-50 needs ~85 seconds if I'm not mistaken. Unfortunately, we probably won't have solid F-35 numbers for some time.

                              @ hopsalot: great, some data for the -402 engined Hornet. Do you have more?
                              Last edited by eagle; 5th April 2015, 16:39.
                              How can less be more? It's impossible. More is more.
                              Yngwie Malmsteen

                              Comment


                                #95
                                Originally posted by eagle View Post
                                Actually, a clean F-16C airframe has a drag index of 7
                                I agree that DI 50 is a good starting point. Less than that is also possible, though unlikely in a real loadout. So at DI 50, top speed is Mach 1.85 vs 1.6 for the F-35. That, imho, is a valid comparison. Now, since the F-35 is not thrust/drag limited at Mach 1.6, it will still have some reserves at that speed. The question is: more than the F-16 at Mach 1.6? I think not, I bet an F-16C @ DI 50 will out accelerate an F-35 from lets say M 0.8 to M 1.6.
                                It takes an F-16C-52 ~110 seconds @ 30.000 feet, the F-16C-50 needs ~85 seconds if I'm not mistaken. Unfortunately, we probably won't have solid F-35 numbers for some time.

                                @ hopsalot: great, some data for the -402 engined Hornet. Do you have more?
                                Most likely, I was responding to a misguided idea that external weapons have a negligible impact on performance. Not specific to any discussion about F-35.

                                Trying to keep F-35 out of this thread as it evokes too many arguments, in too many threads.

                                Comment


                                  #96
                                  Originally posted by eagle View Post
                                  Actually, a clean F-16C airframe has a drag index of 7
                                  I agree that DI 50 is a good starting point. Less than that is also possible, though unlikely in a real loadout. So at DI 50, top speed is Mach 1.85 vs 1.6 for the F-35. That, imho, is a valid comparison. Now, since the F-35 is not thrust/drag limited at Mach 1.6, it will still have some reserves at that speed. The question is: more than the F-16 at Mach 1.6? I think not, I bet an F-16C @ DI 50 will out accelerate an F-35 from lets say M 0.8 to M 1.6.
                                  It takes an F-16C-52 ~110 seconds @ 30.000 feet, the F-16C-50 needs ~85 seconds if I'm not mistaken. Unfortunately, we probably won't have solid F-35 numbers for some time.

                                  @ hopsalot: great, some data for the -402 engined Hornet. Do you have more?
                                  Sorry, I can't remember where the Hornet/Super Hornet chart came from and I don't have any more like it.

                                  I wish we had a more complete set for other fighters. Until then people will no doubt continue to make up whatever they want.

                                  Comment


                                    #97
                                    Originally posted by MSphere View Post
                                    Here a Hellenic Mirage 2000-5EG Mk2 and French Rafale C armed on QRA duty - 2x ARH MICA, 2x IR guided MICA, one drop tank (to be jettisoned).
                                    I have serious doubts the max speed or acceleration after climb is imparted by this loadout in any significant way.

                                    I think that this Rafale is actually carrying 6 AAMs, two Mica EM on the fuselage stations, two Mica IR on the wing tips & the two you can see on the pic on the wing pylons.

                                    Nic

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                                      #98
                                      http://breakingdefense.com/2015/04/t...strike-bomber/

                                      Have to say I'm rooting for NG. Don't think that investing all of the U.S. defense aerospace industries' aircraft design and production in Boeing/LM's mitts for the long term is in the best interest of the taxpayer.

                                      Comment


                                        #99
                                        Originally posted by Nicolas10 View Post
                                        I think that this Rafale is actually carrying 6 AAMs, two Mica EM on the fuselage stations, two Mica IR on the wing tips & the two you can see on the pic on the wing pylons.
                                        AFAIK, Rafales on QRA do not have missiles on fuselage stations.

                                        Comment


                                          Originally posted by FBW View Post
                                          Most likely, I was responding to a misguided idea that external weapons have a negligible impact on performance. Not specific to any discussion about F-35.
                                          as a matter of fact a drop from M2 to M1.85 is a negligible effect on performance,
                                          below 10% which is universally considered threshold between significant/insignificant
                                          ...and that was while carrying a drop-tank too

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