J-20 5th Gen Fighter Thread IV (Closed to posting)

Status
Not open for further replies.

Air Force Brat

Brigadier
Super Moderator
Good summary TE, but just to clarify, the main issue with the Raptor's quick rail launch method is more the drag penalty rather then the RCS hit, since at WVR, RCS doesn't really matter all that much doors open or closed, the enemy has either already seen you and is dogfighting with you, or he hasn't and you are lining him up for an easy kill.

The biggest issue with the quick rail is in the name - quick rails, afaik, they are designed to be able to open and deploy the missile super quick so the pilot doesn't have to do the whole dogfight with doors open, he just needs to keep the lock for a second or fraction of a second longer than normal for the rails to deploy and missile to lock. That can be helpful in a dogfight against a good opponent in a good plane as every little advantage helps, but in that case, you need to be really thorough with your training and actually open the doors every time you simulate a missile launch in training, because opening those weapons bays and sticking a missile out into the slipstream can have a similar impact on the aircraft as deploying air brakes. If you are doing it in exercises all the time and knows what to expect in all kinds of situations and manoeuvres and how to ride out the drag hit and maintain lock, great. Otherwise you might be in for a some unpleasant shocks if you are fighting for real and experience that kind of sudden drag hit for the first time in a real dogfight.

If you are opening the doors all the time for realistic training experiences, that also presents potential issues in itself, such as additional stress and strain on the doors and surrounding supports. Also, knowing about a quirk is not always the same as being able to deal with it. There might be instances that Raptor pilots have learnt when a lock does not let you get a shot off, as the drag hit will throw the lock. Similar deal if you train to have the doors open throughout, as the drag hit will take a few %age points off of the raptor's turn rates and acceleration.

The issues with sudden, unexpected changes in aircraft handling from doors opening will not go away, and may actually be exacerbated by the introduction of new HMCS and AIM9XII.

But, since you seem to find it troubling that we seem to be on the same page so much lately, I'd thought I'd restore the balance a little and find something to disagree with you about. :p I question your characterisation of the computers on the F22 as 'supercomputers', iirc, the computers on the F22 might be super fast in comparison to what was on eariler jets, but wach only has about as much processing power as your IPhone 4. Given how long ago the F22 was designed compared to the other 5th gen contenders and factoring in Moore's Law, I really doubt the processing power of the F22 computer is anything to write home about today. For that reason, I don't think the Chinese rail solution has anything to do with the common suggestion on some forums that LOAL is too hard for the Chinese so they opted to stick the whole missile out instead.

LOAL is a cool feature, but one of the issues with it is that the pilot has to keep the bogey in his sights for a few seconds after missile launch to aid the missile get a lock. If he looks away after launch before the missile has established a lock, its a wasted shot. Although pilots have done it since the beginning of air combat and no doubt will continue to do so until the end of manned aero combat, you are trained not to follow a target to confirm a kill as that puts yourself at additional and unnecessary risk. But that is in effect what you are encouraging with LOAL as the pilot has to keep the target in his sights after launch to use his HMCS to continue to direct the missile rather than getting a good look around his aircraft for new threats and targets as he should.

Actually, I doubt there is little more than a rumble when the weapons bays are popped on the f-22, also the projectiles are very slick in and of themselves, I believe that the f-35 was flown to Mach 1.6 with the weapons bay open during some recent testing. As to the lack of computing power on the F-22, thats rather speculative, as the F-22 was so far ahead of its time, and it did indeed pioneer the sophisticated and stealthy data link with other aircraft, and a hardened avionics suit, I believe they are installing block 3.2 to further expand the Raptors capabilities, soooooo this is still the bird you Don't Want to meet,,,, but don't take my word for it.......but on a much more interesting note, Defense Talk has announced that Xi and Vlad have sealed the deal for 24 Su-35s and 4 Lada submarines, 2 built in Russia and 2 built in China, Defense Talk stated that there would be a great deal more cooperation up to an including the F-117s.....my money says they will end up on our bird, so this is an interesting new developement, probably in response to the obvious weakness in our present leadership when it comes to defense-----just for laughs how about Mrs. Pahlin goes to Washington, I'd love to turn her loose on that crowd, happy Easter kids, I hope the Bunny brings you guys a nice chocolate bunny, I'm actually to old for a basket, so I have to mooch candy from my kids and grandkids???? Brat
 

Player99

Junior Member
Hi Brat, long long time no see! But I actually left you a PM before I took off this time... Anyway, off-topic off. The S-35 deal or ordeal can still become no-deal, as most of us Chinese netizens believe or wish. If it goes through finally (!), it won't be as some foreign observers love to say "the Chinese got their wish" but rather that the Russians got their wish, again as most of us Chinese believe. Sure we Chinese still have much to learn from the Russians, but the Su-35 per se isn't what we really need. So we believe it is more of a helping hand to the Russians. Now the Ladas, many of us believe, would be of more value to the Chinese Navy nowadays.

P.S. When I say "us", sometimes I am not necessarily sure I'm including myself. ;)
 

Jeff Head

General
Registered Member
As to the lack of computing power on the F-22, thats rather speculative, as the F-22 was so far ahead of its time, and it did indeed pioneer the sophisticated and stealthy data link with other aircraft, and a hardened avionics suit, I believe they are installing block 3.2 to further expand the Raptors capabilities, soooooo this is still the bird you Don't Want to meet. ... Brat
If anyone thinks that the current F-22 is limited to what was developed in the 1990s when it first came out...they are whistling past the graveyard.

It's memory capabilities and processing capabilities have been updated and improved with time. They are digital and were designed to take advantage of new processing and memory as they came along. In addition, as you state, the software is contantly being refined and updated too. So the talk about new processing power of the 2010s being able to somehow beat or be ahead of the F-22 is not really relevant because the processors, the memory and the software are all being upgraded as the aircraft goes through its service life. By design.
 

Air Force Brat

Brigadier
Super Moderator
very kool, escobar, on the first go around he selects gear up and rock and rolls, on the second go around he leaves the gear down. On the first one, we see the gear door sequence, where the forward doors are the last to close, you can see that at the test weights the J-20 has excellent acceleration. Brat
 

AssassinsMace

Lieutenant General
Huitong says on his site that the PL-10 is LOAL. If true then all the speculation about China's technological limitations in this matter is moot.
 

TerraN_EmpirE

Tyrant King
Wow seems I just became controversial. Okay lets see here.
First things first.
@ wolf. I am A Joker bud When I posted that is was intended to be a bit funny. LOAL missile systems are a want in systems like Raptor because they are the best option to keep the jet smooth well allowing engagement. as for sudden drag and change in controls.
1 Raptor like most fighters built post F16 uses Flyby wire Controls The computer Adjust the flight.
2 The shift would be momentary a few seconds
3 even conventional Jets Undergo such a change. When 4th gen fighter launches a Weapon it changes the Aircrafts entire configuration in terms of Drag, Slip stream, aerodynamics, Weight distribution. Raptor would have a Advantage in it because she would return to her original configuration. That short door opening of LOAL would only hinder for a second.

@ Brat. I love F22 as much as you do. and if you note gave two variations of F22 Attack. The First was the Current system which is based on the Fact that the AIM9M lacks LOAL capability meaning the Pilot has to get his IR missile to lock Otherwise it's either a snapshot in hopes of a kill which is the fancy term for Firing any weapon round priced over $500.00 form the hip. But i also noted the Scorpion and Aim9XblockII missile which makes those fast opening and fast closing shots possible.

@ everyone. F22 has continued to get upgrades too it's computers and systems.
Now back to J20

@ latenlazy. The Question is one of deployment method. everyone was expecting the guts of the side missile bays to be like those of the F22. these pics remind us that the PLAAF engineers are there own people with their own answers. So then the interior and it's use becomes a question of what is in those bays. We have only seen one or two pics of those doors open. so The Chinese can still surprise We have no idea what is in that bay There could be swing arms meant too move the missile clear of the bay before launch. Or maybe a rotary style launcher to rotate the missile into the air stream or hard points on the doors or any number of options. It's like a christmas Present Everyone Assumes it's that thing you wanted all year, but maybe it's something more interesting... What is it's not the latest Iphone but perhaps jewelry or maybe A box with tickets to the big event or perhaps just perhaps a Set of Car keys. So once more All bets are off.
 

latenlazy

Brigadier
@ latenlazy. The Question is one of deployment method. everyone was expecting the guts of the side missile bays to be like those of the F22. these pics remind us that the PLAAF engineers are there own people with their own answers. So then the interior and it's use becomes a question of what is in those bays. We have only seen one or two pics of those doors open. so The Chinese can still surprise We have no idea what is in that bay There could be swing arms meant too move the missile clear of the bay before launch. Or maybe a rotary style launcher to rotate the missile into the air stream or hard points on the doors or any number of options. It's like a christmas Present Everyone Assumes it's that thing you wanted all year, but maybe it's something more interesting... What is it's not the latest Iphone but perhaps jewelry or maybe A box with tickets to the big event or perhaps just perhaps a Set of Car keys. So once more All bets are off.
The question is did CAC choose that particular solution for the side bays because it reflects a limitation of technology, or because it's a superior solution. I have trouble believing that China wouldn't have LOAL capabilities because that capability is over 20 years old, and because China isn't bottlenecked in the necessary technologies for it. Furthermore, there are potential benefits to the way China has decided to deploy its side bay rails. You can choose to believe that CAC has decided this particular solution as a work around to a limitation, but I don't see any evidence or compelling reason for it.
 

plawolf

Lieutenant General
Wow seems I just became controversial. Okay lets see here.
First things first.
@ wolf. I am A Joker bud When I posted that is was intended to be a bit funny.

Wow bud, don't take offence at my last comment, it was meant as a funny (hence the smilie face), guess its another jokefail for me then. :p

LOAL missile systems are a want in systems like Raptor because they are the best option to keep the jet smooth well allowing engagement. as for sudden drag and change in controls.
1 Raptor like most fighters built post F16 uses Flyby wire Controls The computer Adjust the flight.

Good point on the FBW smoothing out a lot of the rough edges from opening the weapons bays, but FBW can only compensate so much buy itself. I guess the question comes down to just how much drag the weapons bay door generate when they are opened.

We have some knowledgeable members claiming the effects to be minimal, but the doors do look pretty draggy when opened, so I'm at a loss. Does anyone have any comments made by Raptor jocks that might shed some light on this one way or the other?

2 The shift would be momentary a few seconds
3 even conventional Jets Undergo such a change. When 4th gen fighter launches a Weapon it changes the Aircrafts entire configuration in terms of Drag, Slip stream, aerodynamics, Weight distribution. Raptor would have a Advantage in it because she would return to her original configuration. That short door opening of LOAL would only hinder for a second.

Well, the critical difference is that for conventional fighters, the balance shift from weapons deployment comes after the shot has been made, so should not affect the KP of the missile at all. For the Raptor, it needs to open its weapons bay first before it can shoot, thus any impact on the aircraft also directly affects the missile.

A conventional fighter can jerk back violently after missile launch and that movement has no impact on the missile, if the same thing happened to a Raptor as it deployed its quick launch rail, it might be enough to break the lock and spoil the shot.

The main question is how big the aerodynamics impact is when deploying the quick rails on the Raptor?
 

siegecrossbow

General
Staff member
Super Moderator
I don't know if anyone considered this before. Since the J-20 employs a canard configuration, the canards may fluctuate greatly during close quarter combat and may partially block the PL-10's seeker if F-22 style side bays are used. I think the present configuration also grants the seeker a greater field of view.

I got the idea from chuck4's post on Secret Project. I also agree with his assertion that such considerations are indicative of a fighter designed for close-in combat, not a dedicated striker or interceptor.
 
Status
Not open for further replies.
Top