Jet fighters thrust vectoring

[A35K]

So a few days ago I saw this video, of an Sukhoi Su-35 performing at an air show: https://m.youtube.com/watch?v=D9Mocle6Wzk

Well, as you can see some of the maneuvers it can do are truly amazing, and apparently this is the only aircraft in production to have 3-dimensional thrust vectoring, enabling it to do the stuff like at 2:40. Now, are there any other planes planned that will have this capability? I read about some experimental US designs doing stuff like this, but not much else. And anyway, is there really a use in modern air combat for such maneuverability? I thought most air-to-air fights these days were done using long range missiles, at which point the only thing that matters is how good your countermeasures are. However, if you do somehow get in a dogfight against this plane, you might as well bail out immediately..., you've got no chance.

 

By the way, is there any mod for KSP that adds engines like this? Maybe it's doable in stock using the "Vector"?

[Kryten]

F-22 has thrust vectoring in the pitch axis, which is the most useful; only other aircraft with the 2-plane thrust vectoring are the latest version of the MiG-29 family.

The jet engines in KSP already have 2-plane thrust vectoring, it's just quite small (1 degree).

[Shpaget]

Once the unmanned fighters become a reality, such maneuverability might prove to be very valuable. A plane itself can pull much higher Gs than the pilot can withstand, so if you remove the pilot, new limits can be reached.

[PB666]

Technically doesn't the F-35 qualify as thrust vectoring?

 

 

Partial in the third axis

 

 

[A35K]

Does the F-35 use the thrust vectoring only for VTOL or can it be used to enhance maneuverability as well?

I actually found the wiki article about this, it says the only planes with 3D thrust vectoring are all the modern Sukhois, the MiG-35, and some prototypes of highly modified F-16, 18, and 15.

I knew that most KSP engines have thrust vectoring, but unfortunately nowhere near enough at an angle to allow for maneuvers like in the video.

Edited November 30, 2015 by A35K

[K^2]

To get a "3D" thrust vectoring, you need at least two engines with independent two degrees of freedom on their vectoring. The only US production jets with twins have only pitch vectoring. Hence the Russian claim to uniqueness of their jets.

What you need to understand, however, is that Sukhoi specializes on ground attack, light bombers, and CAS aircraft. These are not air-superiority fighters. As indicated above, you don't need a lot of maneuverability for modern BVR combat. It's all about electronics and stealth with these. Ground attack missions, in contrast, frequently require low altitude low speed flights where maneuverability is the difference between getting shot out of the sky from the ground and not. Sukhoi aircraft should best be compared to US F/A and CAS aircraft, like F/A-18 and A-10. Of course, even that style of air support is getting phased out with all sorts of "smart" munition that can be deployed from "safe" altitude, which is why US hasn't really built proper replacements for these aircraft. In contrast, Russians have historically relied a lot more on hardware than software, so they still do CAS the old fashioned way. It hasn't bitten them back yet, but they haven't really been dealing with any sort of a serious ground opposition recently. The fact that they've been sticking mostly to cassette bombs in Syria might be an indication that it just isn't safe to fly your ground attack jets low even if you have the most maneuverable ones in the world.

[JTpopcorn]

I read an article somewhere that said:

1) Within visual range dogfighting isn't going anywhere, this debate has been around since the F-14 in Vietnam War, and within visual range situations still occur, do to better countermeasures.

2) While thrust vectoring is fun, the speeds in which it can have an effect over just control surfaces are slow relativly, and at high speeds it is not needed/does not help. Don't forget planes and people unlike kerbals have g limits.

-JT

[shynung]

8 hours ago, Shpaget said:

Once the unmanned fighters become a reality, such maneuverability might prove to be very valuable. A plane itself can pull much higher Gs than the pilot can withstand, so if you remove the pilot, new limits can be reached.

Yeah, except we need the pilot. Stuff we use to track enemies like IFF, GPS coordinates, IR signatures, and whatnot aren't entirely foolproof. Drones don't check whether the target they're attacking really is an AA installation or just a church. That suspicious unmarked aircraft that popped on the radar might have just been a passing airliner with an inactive transponder. That blob of IR signature might have just been a bulldozer rather than a tank. Given these targets, a drone would have attacked as ordered, while a human pilot would realize that these aren't the targets they're looking for, and fly away.

[Bill Phil]

13 minutes ago, shynung said:

Yeah, except we need the pilot. Stuff we use to track enemies like IFF, GPS coordinates, IR signatures, and whatnot aren't entirely foolproof. Drones don't check whether the target they're attacking really is an AA installation or just a church. That suspicious unmarked aircraft that popped on the radar might have just been a passing airliner with an inactive transponder. That blob of IR signature might have just been a bulldozer rather than a tank. Given these targets, a drone would have attacked as ordered, while a human pilot would realize that these aren't the targets they're looking for, and fly away.

That's why you can use remote piloting, or permission to engage.

[shynung]

2 minutes ago, Bill Phil said:

That's why you can use remote piloting, or permission to engage.

Even that's not without its flaws. Communications with the drone would have delays, due to finite light speed, that slows down reaction time compared to a manned aircraft. It ranges from a few microseconds to several seconds. That few seconds might be the difference between pulling away on a mispainted target or wasting a missile on a schoolbus or general aviation aircraft.

In short, drones are decent fliers, but ruthless fighters.

[Bill Phil]

Just now, shynung said:

Even that's not without its flaws. Communications with the drone would have delays, due to finite light speed, that slows down reaction time compared to a manned aircraft. It ranges from a few microseconds to several seconds. That few seconds might be the difference between pulling away on a mispainted target or wasting a missile on a schoolbus or general aviation aircraft.

In short, drones are decent fliers, but ruthless fighters.

The thing is, the drone would send a request to do something to a nearby control center, which could be mobile. Then the control center would send a go/no go.

It has its flaws, but it's better than nothing.

[K^2]

38 minutes ago, shynung said:

Yeah, except we need the pilot. Stuff we use to track enemies like IFF, GPS coordinates, IR signatures, and whatnot aren't entirely foolproof. Drones don't check whether the target they're attacking really is an AA installation or just a church. That suspicious unmarked aircraft that popped on the radar might have just been a passing airliner with an inactive transponder. That blob of IR signature might have just been a bulldozer rather than a tank. Given these targets, a drone would have attacked as ordered, while a human pilot would realize that these aren't the targets they're looking for, and fly away.

Experience shows that humans don't check these things very well either. It's a combination of factors, from pilot not wanting to risk own life on a chance it's not the right target, to our general trust in instruments. After all, modern fighter is practically flown by the computer. All we have to do is make drones make fewer mistakes than our pilots, and that bar isn't as high as it seems. During operations in Iraq, we've had incidents of friendly fire where pilot checked with ground control and got authorization to destroy targets that turned out to be friendlies. Pilot was uncertain, saw no immediate threat, requested confirmation, received it, and still fired on allied vehicles. It's nothing a drone couldn't have done. Except, drone would never fire due to lack of experience or out of fear.

Human element must be maintained. And there will certainly be situations where you want a human in the plane, but there are also a lot of situations where you can completely rely on drones. If you want to set up a guaranteed no-fly zones to anything without an IFF, drones are a good way to do this. If you want to then carry out air-strikes from within such a zone, you can use remote-controlled UAVs.

[Shpaget]

There are different types of unmanned. One is just a remote controlled plane where the pilot on the ground has full control and flies just as if he was in the cockpit.

Then there is a hybrid where the pilot guides the aircraft but actual control is done by the onboard compute r (think of your GPS in a car that tells you to turn left on the next intersection, but you need to actually turn the wheel; only here roles of computer and human are reversed). This is even done on modern RC toys. I've had a chance to work with DJI Phantom. That thing does all the flying itself, you only tell it where to go and it takes care of how to get there, what motors to spin up or down, how to tilt or roll and even stabilizes the camera for you.

And then there is the completely autonomous drone that will fly roughly according to a predetermined flight path and, if allowed to, engage non-friendly targets.

Of course there is a sliding scale on this where each aspect can be automated or manual, depending on the scenario and mission profile. The point is that a pilot that is safely sitting in a bunker can take his time to properly examine the potential target without the need to dedicate a portion of his mental capacity to keep the plane from slamming in the ground, since the plane itself will take care of that. As mentioned earlier, it also removes the fear of death and the probably a portion of the itchiness in the trigger finger.

[AeroGav]

The thing about dogfighting is that it generally takes place at the lowest airspeed the jet can sustain 9g (the maximum a human can withstand) - sometimes you want to go faster than that, but it's very seldom a good idea to drop below your aircraft's "corner speed".**

A 9G, "corner speed" manoeuvre not only swivels the nose around quickly, it changes the jet's position very rapidly too.   It can move you from being in front of an enemy to being on his six, swivelling about your axis at low speed with vector thrust may give you a brief opportunity to fire back, but doesn't really take you out of his sights.

Generally, wings are best kept for providing lift and engines for providing thrust.    Wings have a lift:drag ratio of 10:1 or more, effectively turning 1 pound of engine thrust into 10 pounds of  lift.    A fighter aircraft can easily generate 9 times more lift than it weighs, hence the 9g turns, but it's thrust barely exceeds it's weight at all - it can do little more than 1g on thrust alone.

Thrust vectoring comes into it's own in three situations

1. Vertical takeoff and landing

2. Adding one extra G of thrust - derived lift, when the airspeed is too low for the wings to hit 9g by themselves.   Note this is a very short term strategy, for a slight increase in turn rate, it will make your airspeed bleed off rapidly and soon you'll be even less able to turn than you would have been without vectoring.

3. Getting the nose up.

The last of these is the most important.   Airframes are optimised to perform best at certain speeds and altitudes and a lot of fighters become nose heavy at low speeds.   This is compounded by the short tails these aircraft have - the tail surfaces are very close to the wing (f22 anyone?), so because of their short lever arm, it takes an enormous amount of downforce from the tailplane to get the nose up.  Creating that downforce costs drag and furthermore, that downforce subtracts from the lift generated by the wing.

Canard designs suffer less from this problem because their pitching surfaces are actually helping to create lift when pulling the nose up, so there is less need for thrust vectoring.  But they are inherently less stealthy.
 

**So ,  an ideal dogfighter needs as much lift as possible, to give the pilot the option of turning at 9g down to the lowest possible airspeed.           An turn rate, in degrees per second, depends upon the airspeed divided by the acceleration in "G".  It will take half the amount of time to complete a turn at 9G and 250knots as it would at 9G and 500knots.

However, a fighter also needs to be fast, and larger wings can create more drag when flying fast and not turning hard.   The clever stuff in aircraft design is in trying to get the best of both worlds.

 

***As others have mentioned, historically 8 out of 10 air combat kills did not involve a dogfight, the victim never saw his attacker and took no evasive action.  That is why. throughout WW1 and WW2, the trend was for successively faster but less maneuverable fighters.      If a slower group of fighters spots its enemy without being seen, it may not be able to convert that opportunity into a kill if it cannot catch up to them to get in firing range.

Edited December 1, 2015 by AeroGav

[K^2]

8 minutes ago, AeroGav said:

The last of these is the most important.   Airframes are optimised to perform best at certain speeds and altitudes and a lot of fighters become nose heavy at low speeds.   This is compounded by the short tails these aircraft have - the tail surfaces are very close to the wing (f22 anyone?), so because of their short lever arm, it takes an enormous amount of downforce from the tailplane to get the nose up.  Creating that downforce costs drag and furthermore, that downforce subtracts from the lift generated by the wing.

This is not true of modern fly-by-wire fighters. On older planes, decision to make them nose-heavy was down to stability. Nose-heavy aircraft will naturally dive if speed is too low, or pitch up if speed is too high. So once you're trimmed, any changes in thrust will simply result in a climb or descent. In contrast, a tail-heavy aircraft is inherently unstable. It has tendency to dive or stall, and the pilot has to constantly fight the controls. On a fly-by-wire jet, this fighting can be shifted over to the computer. The aircraft is designed to be completely unstable and uncontrolable without the computer doing constant fine adjustments to all the control surfaces. This has an entire host of benefits. First, the tail on such an aircraft is lifting, not dragging. So the net drag is lower for the same lift. Maneuverability is higher, since aircraft has natural tendency to pitch over. And finally, for the same reason, the response time between pilot's input and plane actually turning is reduced. You get performance, precision, and maneuverability, all at the cost of needing a computer between the stick and the surfaces.

And yeah, canards exist essentially for the same reason, but it was basically just an attempt to get the same performance gains without needing a computer. On modern fighters, however, they serve a completely different purpose. While general aviation canards generate positive lift, fighter canards are designed to generate negative lift, just like a tail of a conventional aircraft. The purpose of this, again, is to make fighter less stable. This actually sacrifices performance for maneuverability, so it's mostly limited to experimental aircraft and a handful of European fighters. And its absence on US fighters is not due to stealth. F-15 is a perfect example of a pre-stealth aircraft that's designed to fly by wire. It is inherently unstable and tail-heavy. Both its wings and tail generate positive lift.

[SomeGuy123]

So, ok, on the "drone vs manned" fighters argument : it's kind of like the classic "John Henry" story.  Right now, today, an apples to apples fight with a manned vs unmanned version of the same aircraft, the manned fighter is probably better.  Partly this is because the aircraft aren't designed to take advantage of the things an unmanned fighter is capable of like high G turns.  

In the relatively near future, you could have hybrid systems.  Those fancy air combat maneuvering turns and other extreme maneuvers that we consider an essential part of "dogfighting"?  The drone could have cameras facing every direction, both infrared and visual light, and it would track the rough position of the enemy fighter it is dueling.  Humans would essentially pick from a menu which fancy maneuver to perform next, ("do a barrel roll!"), with the drone software using the exact position of the enemy aircraft, relative velocity, taking into account engine thrust, air pressure, air temperature, and automatically adjusting throttle/activating afterburner to perform the maneuver optimally.   Basically just like how an aimbot that corrects for enemy position, movement, weapon spread, and bullet drop is a lot better than aiming manually in an FPS game.  So much better it's considered cheating...

Human programmers and ace fighter pilots would work together to program these "combat scripts".  It's not an AI, it's the drone executing a pre-planned maneuver, correcting for present conditions, flawlessly every time.

The other factor here is that since a pilot isn't onboard, you can manufacture the drone aircraft to shoddier standards.  A small increase in the probability of failure for each mission can be accompanied by a large reduction in manufacturing costs.  Another idea is that you'd have 2 lines of aircraft.

You would have "training" drones, manufactured to be maintainable and made of gold plated components.  These aircraft would be the ones you practice with when not using the simulator.  The other line would be the "war" drones.  They would be sealed in packing cannisters, ready to go, sealed away from air and moisture and sunlight and everything else.  After about 10-20 years they would be considered "expired" and you'd unpack the drones and fly them, both to test the packing process, and then you'd load them with live munitions and have them fight each other for real at somewhere like Fort Hood, so drone pilots can get practice with live weaponry.  The war drones would intentionally be expected to be an expendable weapon, capable of only 100 or so hours of operation or so, made to a cheap standard and you'd consider a 10 or 20% post-storage failure rate to be fine.  You'd plan on sometimes using the war drones on kamikaze missions where you would not bother to refuel them.

Edited December 1, 2015 by SomeGuy123

[shynung]

4 hours ago, Bill Phil said:

The thing is, the drone would send a request to do something to a nearby control center, which could be mobile. Then the control center would send a go/no go.

It has its flaws, but it's better than nothing.

Hmm. I guess mobile CCs for drones would be the way to go.

[A35K]

18 hours ago, K^2 said:

To get a "3D" thrust vectoring, you need at least two engines with independent two degrees of freedom on their vectoring. The only US production jets with twins have only pitch vectoring. Hence the Russian claim to uniqueness of their jets.

What you need to understand, however, is that Sukhoi specializes on ground attack, light bombers, and CAS aircraft. These are not air-superiority fighters. As indicated above, you don't need a lot of maneuverability for modern BVR combat. It's all about electronics and stealth with these. Ground attack missions, in contrast, frequently require low altitude low speed flights where maneuverability is the difference between getting shot out of the sky from the ground and not. Sukhoi aircraft should best be compared to US F/A and CAS aircraft, like F/A-18 and A-10. Of course, even that style of air support is getting phased out with all sorts of "smart" munition that can be deployed from "safe" altitude, which is why US hasn't really built proper replacements for these aircraft. In contrast, Russians have historically relied a lot more on hardware than software, so they still do CAS the old fashioned way. It hasn't bitten them back yet, but they haven't really been dealing with any sort of a serious ground opposition recently. The fact that they've been sticking mostly to cassette bombs in Syria might be an indication that it just isn't safe to fly your ground attack jets low even if you have the most maneuverable ones in the world.

I'm not necessarily saying they are good at it, but weren't the Su-27 and 35 designed mostly with air to air combat in mind? 

Another interesting thing to note is that apparently the Sukhoi T-50 PAK-FA is also equipped with 3-D thrust vectoring, yet it is a stealth aircraft. So why is this? Is it a less effective type of stealth than the F-22 and F-35 use?

[Nibb31]

Yes, Su-27 and 35 are air-superiority fighters. Because they are multirole, they do have a gound attack capability, but they were primarily designed as long range interceptors.

Stealth is always relative. There is no such thing as an "invisible" plane. The technical term is "low radar signature", and this is done through clever design and materials, but it has drawbacks. 

If you look at the latest Russian fighters, you'll notice that they have small black domes in front of the cockpit. These are for detecting "stealth" aircraft's IR signature and can be couple with the latest generation radars. Even a B-2 will leaves some hot air behind it at 50 000 ft and any aircraft will heat up when flying at Mach 2. 

So the US has a doctrine of favoring low radar signature vs other capabilities, and they spend a lot of money on that. Other countries have different priorities because either they don't trust stealth technology or they have other sets of requirements. For example, the Rafale has some elements of stealth, but they didn't want to compromise on performance or cost because they don't think it's worth it. The same is true for most Russian aircraft.

 

[K^2]

1 hour ago, Nibb31 said:

Yes, Su-27 and 35 are air-superiority fighters. Because they are multirole, they do have a gound attack capability, but they were primarily designed as long range interceptors.

It's kind of like saying that F/A-18 is primarily an interceptor. Yes, air combat capability was a key requirement. But a lot has been sacrificed to make it a better ground attack plane. Neither Su-27 nor Su-35 could remotely compete in an even air combat against same generation of dedicated US fighters. And if that was their main role, they'd be entirely non-competitive on the market. Yet they are. Because they make pretty decent front line fighters.

[A35K]

1 hour ago, K^2 said:

It's kind of like saying that F/A-18 is primarily an interceptor. Yes, air combat capability was a key requirement. But a lot has been sacrificed to make it a better ground attack plane. Neither Su-27 nor Su-35 could remotely compete in an even air combat against same generation of dedicated US fighters. And if that was their main role, they'd be entirely non-competitive on the market. Yet they are. Because they make pretty decent front line fighters.

Well, I would say that an F/A-18 is mostly evenly matched with an F-16 in air to air. There is no reason an Su-35 would not be able to take down an F-16 or F-15. Look at the Russian involvement in Syria, which at the moment is purely ground attack, they are using mainly Su-24, Su-34, the ones that are actually ground attack aircraft. After all, every jet fighter could be considered multirole, since even Air Superiority fighters like the F-15 can be equipped with bombs and other air to surface weaponry. 

[K^2]

1 hour ago, A35K said:

Well, I would say that an F/A-18 is mostly evenly matched with an F-16 in air to air. There is no reason an Su-35 would not be able to take down an F-16 or F-15.

You've started with something I find hard to believe, and progressed into pure fantasy. All else being the same, F-16 has a number of advantages over Su-35 in pure air-to-air combat which while do not guarantee outcome will statistically weigh heavily in favor of F-16. A group of modernized F-15s will wipe out similar group of modern Su-35s almost certainly without losses. There is no competition there.

Again, all Sukhoi aircraft are front line fighters at most. Which means they are not designed to assure air superiority solo. If you want to bring up Syria here, would you please recall what Putin's response to downing of the Su-24 was? Did he order some Su-35s to protect Russian bombers? No, because that'd be useless. He has ordered S-400 AA systems delivered to Syria. This was part of the Soviet doctrine as well. Soviet aviation was never envisioned as operating completely independently from ground forces. Which is very different from US doctrine of aircraft operating remotely by themselves, which is why US spent so much money developing actual superiority fighters.

[J.Random]

On 01.12.2015, 1:29:44, K^2 said:

they've been sticking mostly to cassette bombs

Neither KAB nor (O)FAB are cassette bombs. When you see multiple small "explosions" on videos from russian defence ministry, it's nothing more than dust blowing from the ventilation shafts of destroyed underground facility.

17 hours ago, K^2 said:

Did he order some Su-35s to protect Russian bombers? No, because that'd be useless.

Actually, yes, fighters are escorting bombers since the incident and bombers themselves are armed with air-to-air missiles, as well as S-400 and "Moskva" cruiser (equipped with "Fort" system which is roughly equivalent to several S-300 systems) were deployed.

 

Sorry, but you're the one fantasizing here.

[A35K]

20 hours ago, K^2 said:

You've started with something I find hard to believe, and progressed into pure fantasy. All else being the same, F-16 has a number of advantages over Su-35 in pure air-to-air combat which while do not guarantee outcome will statistically weigh heavily in favor of F-16. A group of modernized F-15s will wipe out similar group of modern Su-35s almost certainly without losses. There is no competition there.

Again, all Sukhoi aircraft are front line fighters at most. Which means they are not designed to assure air superiority solo. If you want to bring up Syria here, would you please recall what Putin's response to downing of the Su-24 was? Did he order some Su-35s to protect Russian bombers? No, because that'd be useless. He has ordered S-400 AA systems delivered to Syria. This was part of the Soviet doctrine as well. Soviet aviation was never envisioned as operating completely independently from ground forces. Which is very different from US doctrine of aircraft operating remotely by themselves, which is why US spent so much money developing actual superiority fighters.

Well, keep in mind I am neither American nor Russian (nor from a country which has strong ties with either of these), so I have (or at least trying to) have no bias here. I

agree that the US and Russia's use of aviation differ greatly. But claiming that one of the most modern jets on what is probably the world's 2nd or 3rd largest air force  cannot destroy a single one of its (older) counterparts is quite ridiculous. If that were true, why would they even bother having anti-air missiles on Sukhois? And while an F-15 might prevail due to the advanced avionics, etc., it is simply not possible that it would be completely untouchable. Hell, it's not even stealth! And anyway, when has using aircraft by themselves without troops on the ground ever proved useful? Sure, it can "contain" or stop the advance of an enemy, but air strikes alone won't defeat an enemy (unless you carpet bomb or use nukes, but that is extremely unlikely to happen in any modern conflict). This is also why every one bombing in Syria has some allies on the ground: Rebels for the US and Syrian Troops for Russia. Otherwise, airstrikes would just be a waste of money.

Edited December 2, 2015 by A35K

[PB666]

Apologies to the moderators, but I can see this thread going nowhere.

Apply https://en.wikipedia.org/wiki/Black_swan_theory to war. It should be rather apparent to the US and Russia that setting nationalism aside it is almost always better to work with potential foes than against them, war is often very unpredictable as would be head to head confrontation in military styled A/C. Iraq is a training ground, it wasn't needed, we saw the same phenomena in the Indian wars of the late 1800s. You bring in Humvees, the enemy brings in IEDs, you bring in better protected vehicles, they then modify the explosives. Arrogance turns soldiers into fodder.