HotshotA cheap (5,5 or)6-gen plane? Actual ones are just so costly than anything designed to superate them would be a budget breaker anyway.
Let say that if F-22 has to be considered as a 5,0 gen aircraft both F-35 than the T-50, but in a lesser way also the Y-20, has taken some evolutionary step toward a new generation or better to the half of it, if we want to stitch to my initial post.
6th gens might be unmanned or optionaly manned. So the unit cost might be very high, but the operational cost will be much lower. Usually the cost of purchasing a fighter is like 30% of the overall cost during its service life. It might be more like 50-60% on a 6th gen if it is unmanned/optionaly manned.
HotshotTrue, a 42% increase in thrust can make huge difference; actually allows good old MiG-21 to counter 4th gen fighters with a 2nd gen fighter in climbs and acceleration. In wartime that would be acceptable, otherwise a MiG-21 has no use other than being a target practice to modern aircraft (as proven by F-15). If such application ground your fleet in 3 weeks, thats good because otherwise you would lose them in 3 days.
However, for modern applications, even if increase in thrust translates directly to climb, acceleration and sustained turn performance, what difference a ~10% thrust increase would make in emergency? Sustaining 11 deg/s instead of 10 deg/s, or accelerating to 300 to 410 knots instead of “only” 400 knots won’t save you the day in any real life scenario.
With 10% more thrust the plane could supercruise, which would decrease the probability of detection by IRST. It would also help have more speed to escape. An F-16 or F-15 could possibly supercruise with a centerline tank and external pylons.
In visual range, having 10% more thrust probably wouldn’t make much difference, it would be more interesting to find a way to increase the aoa to help achieve a fast AIM-9X shot. It looks like the era of energy maneuvering is over.
And remember, such big increase was possible to R-25 engine due to decades of advances in science&engineering. Engines like EJ-200 or F-119 are already latest in technology. I don’t think anyone could squeeze more out of them without severely compromising longevity of the engine.
Modern engines are good for thousands of hours ( 8000h for the F135? ), so I find it hard to believe it would be impossible to get 10% more thrust in case of emergency for a few minutes. Even if the engine life is reduced by say 100h, if it can help the plane survive, it’s a good deal. In particular, the F-35 would benefit from that because it could help it to supercruise. Otherwise it can’t do it so either it has to use the AB on a reduced setting to stay supersonic or it will be forced to decelerate in subsonic.
HotshotDoes the fighter then use PTR so that it has the rpm lower than max or is the throttle quadrant changed. Most common is throttle movement to max rpm (max dry)to a stop then unlocking to go further to engage the reheat. PTR was used in the Jaguar for lower rpm (85% and above) to make the thrust changes more manageable.
That is what I was asking, does the EJ200 use water or water/meth?
Why have a war time switch when thrust can be altered with the throttle?
I don’t know the details of it. I had in mind that it was a switch, maybe it’s not. I don’t know if the feature is already implemented or if it’s for a future upgrade of the EJ200.
HotshotTransonic acceleration requires more thrust than being low supersonic. The drag in the transonic region is much higher. Also accelerating through the transonic region without reheat can use more fuel (it takes longer). Concorde accelerated through the sound barrier using reheat. Once past they would cut off reheat and accelerate to Mn 2.0 with dry thrust.
A fighter would accelerate through the transsonic regime with its reheat and would continue to use it up to its supercruise speed. Then it can turn off the AB and turn on the extra thrust setting in military, so it can sustain tha speed better.
Btw that feature used to max the thrust, which one was it? Water/methanol injection or just moving the throttle to max? The Pegasus used in the Harrier was fitted with water injection for hot and high work.
Boeing 707’s also had it. When they were taking off with thrust augmentation (that’s what it falls under) the smoke they produced was rather imposing.
You’re talking about the typhoon? I am not sure but I doubt it’s water/methanol injection.
HotshotThe EJ series have undergone a lot of development. It is normal that an engine is continuously improved, certainly in the first years of service. When the Tornado was first in service the RB199 was regularly upgraded and improved. There was even a ‘10%’ turbine fitted. This gave 10% more power at a set TGT or, as they chose, to run at a lower temperature and still produce the same thrust.
The same can be said about other types. Many other engines from other a/c types were improved over the years, Lightning, Buccaneer, Phantom, Jaguar, even Hunters, Vulcans and Victors!
Using a ‘war setting’ to increase the supercruise? Are there any aerodynamic improvements on the a/c? Don’t forget the drag rule 2 x 4, simply said, double the speed, quadruple the drag.
As I pointed out that even old a/c had something similar but would have only been used under very special circumstances, I never saw one used.
It was interesting to read the data. The EJ has roughly the same mass air-flow compared to the RR Avon 300 (RB146) that is 170lb/s compared to 171lb/sec, yet the thrust is so much higher.
Not only is it the increased working temperature but also the internal aerodynamics. The PR is much higher with fewer stages which indicates less internal losses. Using a very low bypass ratio is better for supercruise. The RB146 is a pure turbojet, the Lightning could also supercruise, in the early ’60’s even! Fluid dynamics and material improvements have increased the performance of the engines these last few decades. Interesting to read about the con-di thrust nozzle. the RB146 was trialed with this in the early ’60’s for a mirage III. The sale didn’t go through though.
Modern engines like the EJ are better at sustaining high temperatures, so they can better sustain supersonic speeds. The goal is to at least stay in supersonic with the extra military thrust. Using the AB should be restricted to accelerating at long range far from the targets to avoid being detected by the enemy’s IRSTs.
So apparently, it might be true that the typhoon has that war time engine setting so it might well supercruise near mach 1.4-1.5.
I didn’t know that british engines were upgraded with that kind of setting systematically. The 10% extra thrust on the RB199 must help the tornado F3 to have a better acceleration.
HotshotI know russian carrier-based planes has such a feature to have maximum possible thrust on takeoff.
It can be useful when similar short duration necessities arise as taking off, consistent SEP loss and reaching supersonic , no way it would be used in dry thrust however.
It seems like every modern engine should be capable of that kind of short duration extra thrust setting.
A fighter can accelerate with its normal engine setting on AB up to its supercruise speed. When it’s approaching the target, it can use the extra thrust setting in mil and turn off the afterburner to avoir being detected in IR. This way it can better sustain its supercruise speed for the time of the engagement.
HotshotSide and rear looking Aesa array would do the trick, no sense however to launch a missile to hit something at your own back as it would have an awful practical range, better to made a 360° degree turn and launch it when you are between 90° and 180° degree and keep on going.
Agreed on the kinetic aspect of it. But a 360° IRST would provide 360° detection and tracking at a significantly lower cost than side AESA arrays. Against LO targets an IRST might have the same kind of range – might depend on weather conditions. If you are trying to lower the cost of the plane the all aspect IRST saves maybe several millions.
The plane would have to turn in the direction of the target for the launch to increase the missile’s range, but right after the launch the plane can escape while continuing to guide the missile.
One thing however, concerning the use of a HEL, is the accuracy of the tracking of an IRST vs a radar. In order to use a laser, I guess the most important is to have the best accuracy in direction, an IRST might be better than a radar for that, not sure
HotshotI think DAS’s primary objective is to detect threats like missiles, so it cannot scan like an IRST, it needs to watch constantly everywhere, hence a wide angle sensor. However, it would probably be possible to make a 360 degrees real IRST, either with one turret or several. It would be good to guide missiles at 360 degrees in BVR up to 50-100km but it wouldn’t replace the something like the DAS.
HotshotInteresting, it looks like the british are interested in that kind of capability.
http://typhoon.starstreak.net/Eurofighter/engines.html
An interesting point to note is that the baseline production engine is also capable of generating a further 15% dry thrust (69kN or 15525lbf) and 5% reheat output (95kN or 21263lbf) in a so called war setting. However utilising this capability will result in a reduced life expectancy.
Sometime you hear about the typhoon’s ability to supercruise at Mach 1.4-1.5, maybe it is with this 15% extra thrust.
HotshotThis is it. 🙂
HotshotVLO will be a no-issue, it the sense that anyone relevant around there would have mastered it enough to have it in all their future fighters.
Think most relevant progress would be to get beyond actual turbofan engines toward scramjet or pulse detonation engines .
As it would take quite time I think however there would be space for a sort of 5.5 gen: unmanned version of actual fighters with variable bypass engines and a full 360° sensor coverage.
I even wonder about the possibility of converting existing F-35s into UCAVs in the 2030’s. Replace the cockpit with a HEL or more fuel. That would give massive operational saving and increased service life.
HotshotThose are follow-on development enhancements on a natural upgrade path and should happen every major block. It would be a cost vs capability trade. If they think there is good enough reason to upgrade that hardware they’ll do it, if not they’ll keep them as such and let new builds get that capability. Block 3I hardware is essential to Block 3F and block 4 capability, whereas all other things are an improvement over baseline capability. Much like the Rafale or Phoon adding an AESA or changing or upgrading to a newer generation pod…The Marines may decide to keep a certain number of aircraft @ baseline capability as far as things like EOTS and other non-essential changes are concerned while the USAF may decide to upgrade all capabilities. That is always going to be a moving target. There is a cost component to the follow-on development phase be it block 4, block 5 or block 6, and it is the budget situation that will ultimately determines what shape these blocks take and what capability developed is absorbed fleet wide or left for new jets coming off the production line that should be HOT well into the 30’s. I’d need to go back and look at the SAR projections again but from what I can remember the majority of the F-35 deliveries will be in the block 4 or higher variants.
I think the marine F-35s will absolutely need the IR pointer and rover capabilities, since CAS will be one of their primary roles. The USAF might decide differently with its fleet. They might decide to keep some of the early F-35As without those capabilities and keep those planes more for penetration strike, SEAD, etc… , although they will still have the secondary CAS capabilities.
The thing is to not have to change too much hardware too soon, because it costs a lot. In particular the 3 year 500 planes buy should be done when the plane is sufficiently mature to avoid expensive upgrades almost right away.
HotshotThose are follow-on development enhancements on a natural upgrade path and should happen every major block. It would be a cost vs capability trade. If they think there is good enough reason to upgrade that hardware they’ll do it, if not they’ll keep them as such and let new builds get that capability. Block 3I hardware is essential to Block 3F and block 4 capability, whereas all other things are an improvement over baseline capability. Much like the Rafale or Phoon adding an AESA or changing or upgrading to a newer generation pod…The Marines may decide to keep a certain number of aircraft @ baseline capability as far as things like EOTS and other non-essential changes are concerned while the USAF may decide to upgrade all capabilities. That is always going to be a moving target. There is a cost component to the follow-on development phase be it block 4, block 5 or block 6, and it is the budget situation that will ultimately determines what shape these blocks take and what capability developed is absorbed fleet wide or left for new jets coming off the production line that should be HOT well into the 30’s. I’d need to go back and look at the SAR projections again but from what I can remember the majority of the F-35 deliveries will be in the block 4 or higher variants.
I think the marine F-35s will absolutely need the IR pointer and rover capabilities, since CAS will be one of their primary roles. The USAF might decide differently with its fleet. They might decide to keep some of the early F-35As without those capabilities and keep those planes more for penetration strike, SEAD, etc… , although they will still have the secondary CAS capabilities.
The thing is to not have to change too much hardware too soon, because it costs a lot. In particular the 3 year 500 planes buy should be done when the plane is sufficiently mature to avoid expensive upgrades almost right away.
Hotshot… such as modifs to the EOTS for IR pointer, ROVER capability, modifs to the internal bays to be able to carry 8 SDB2s. And check the upgrade path, it includes crypto upgrades, ICP upgrades for communications, power/thermal management improvement, link-16 to VMF update, wideband com phase infrastructure, PMA, ALIS phase II. All those look like hardware to me.
Note also the huge costs of the F-22 upgrades. Hopefully the F-35 upgrades won’t cost anywhere as much but they will cost a significant amount probably.
HotshotThe money buys you capability from a hardware perspective that lasts through all of block 4 and would most likely changed or upgraded as the program transitions from block 4 to 5 late next decade. That’s a decade to 15 years worth of software and capability enhancements that that $4 million buys you.
4 million is of the order of the cost of mass produced SABR for an F-16, it is not cheap change.
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