J-20 5th Gen Fighter Thread VI
- Thread starter siegecrossbow
- Start date
- Status
All missiles have only as much total energy as the amount of propellant plus initial launch speed. While the missile is traveling it is also bleeding energy due to drag. High G maneuvers bleed more energy because they convert linear momentum into angular momentum. That also translates to an initial loss of speed (or more precisely since the missile is still accelerating from thrust a loss of linear acceleration). The missile needs to reacceleate along its new linear vector as it’s executing the high G turn. This is very energy expensive.
Of course a missile is better than a gun. No one said otherwise. The question was whether it’s worthwhile to have a gun, not whether a gun is better than a missile.
Do you know why a missile needs 5 times the G force? Hint, it has something to do with the different starting energy and position of the missile relative to its target. This 5 times thing is a gross oversimplification that you’re extending way beyond any analytical value. If the target you’re trying to hit is faster, higher, and/or further away, your missile will probably need to be able to pull more Gs or else travel much faster than if your target is slower, lower, and closer. A missile that can pull 60 Gs will have a more extended maneuver envelope than a missile with 45 Gs but all that’s moot if pulling those Gs means the missile loses too much of its limited energy reserve to either catch or reach its target. A fighter doesn’t need to pull 12Gs to dodge a missile that can pull 60 Gs if the missile has bled most of its energy by the time its reached the target. Fighters evade by rolling and turning the moment they’re locked on precisely to force the missile to maneuver early to bleed its energy, to increase the likelihood that the missile won’t have enough energy to reach or catch it after a high G terminal maneuver. A fighter has enough energy to pull several 9 G maneuvers in different directions but a missile may only have enough fuel to pull one or two 45-60 G turns before it loses too much energy. Please employ real physics next time rather than amateur back of the envelope calculations. This isn’t an video game where you can number crunch basic stats to get definitive answers for damage and hit probability. The real world is significantly more complicated.
You're obfuscating with your implied claim that missiles never work, when the fact has always been that missiles have an effective range against a target of specific energy and maneuverability. That's always a fraction of their max range, but the long max range means that the missiles always outrange guns when it comes to effective range. If the point is that the more maneuverable fighter reduces effective range more, that's a matter of instantaneous turn rate, when dogfighting requires sustained turn rate. Dogfighting is, in all probability, obsolete.
And, as to this topic:
Off-topic. If you want to discuss it elsewhere, that's fine.
And, as to this topic:
Off-topic. If you want to discuss it elsewhere, that's fine.
I used yahoo
I never said missiles never work. I was explaining why NEZ figures shouldn’t be taken at face value, and why effective ranges are a lot more variable than the simple back of napkin calculations you seem to like to substitute for real physics. You either need to work on your reading comprehension or you need to stop trying to misrepresent other people’s arguments to try to win ego points. BSing doesn’t substitute for a lack of analytical rigour.
I think the latest built J-20s do use some variant of WS-10. It's difficult to be sure since we don't know which ones are the latest builds and there are very few photos of J-20s as it is.
It's not only about whether the relative weight and relative space of a CIWS on a ship is comparable to that of a gun on a fighter jet.
It's also about both being the last ditch defences for their respective platforms.
If we take Yankeesama seriously then J-20 is intended to have a gun. It might be because it has yet to be equipped with one due to thrust/weight. Or it might be that they're developing a new gun and it has yet to finish development, and once it's done it will be refit to all J-20s.
In any case I think based on the current information we have it is a non-viable argument to suggest that J-20 is not intended to have a gun by design.
I think it is more accurate to say J20 is intended to have a gun in the 2000s when it was under design phase. Its future doctrine may or may not incorporate a gun.
This is similar to the American ATF program in the 1990s, where people are not sure of what next gen A2A combat will be like. Simply because speed and maneuverability were important in the previous generation, those performance were viewed as valuable for ATF. China has a better idea of the importance of sensor and net working over kinematics, but completely removing the gun is too big of a risk, so it has its place reserved. As J20 development proceeds, it becomes more clear that guns are not worth the trouble on logistics, maintenance (gun fires could damage stealth coating), and weight, therefore PLAAF is in no hurry to include the gun, if ever. After all, F35B and C do not carry guns as well, so the Chinese are not the only ones that do not emphasize a gun for their 5th gens.
No, all J-20s we know - at least those for operational units - fly with the AL-31FN-xzy and so far only one is confirmed with the WS-10.
- Status