Could someone redpill me on single vs twin engine jet-fighters?
A meme born of the USN not wanting to use the same fighter as the USAF (F-16's).
1 is cheaper, 2 is better.
>>30647905
1 engine is more fuel efficient.
2 engines is faster.
That's 90% of what you want to know.
>>30647905
1 Is lighter, cheaper, and more versatile
2 is expensive, faster and better for air superiority
>>30648010
>>30647949
'better' isn't a reason
>>30648098
That's a nice opinion you have.
>>30648115
Pointing out your opinion is an opinion is not itself an opinion.
>>30647905
With 2 engines you can still fly if 1 fails, 1 big engine isn't cheaper than 2 small ones either, 2 engines doesn't have to be faster than 1 big one either.
The only difference in theory is that you have 2 and they don't both have to fail at the same time.
>>30647977
>>30648010
I figured as much, but I find it interesting how the US chose to develop a 5th generation single engine fighter whereas both China and Russia went with twin engine models
>>30648171
but according to our infallible experts here at /k/ modern aircraft engines *never* break during flight/cannot be hit by enemy/will never suck a bird/otherwise become inoperable & anyone who wants to have a plane with two engines when they could get a plane with just one is a retard
>>30648222
Neither country can make an engine as good as the one in the F35 right now. They had to choose two engines.
>>30648287
>statistics trigger me
>>30648171
An engine failure in a twin engined fighter usually leads to a crash.
Single engine is lighter weight, twin engine means higher power and also better energy retention through maneuvers which matters a lot.
>>30648222
say what you will
that is one sexy as fuck aircraft
>>30648431
J-20 is sexier
>>30648464
but nothing is sexier than this baby
>>30647945
>not knowing that USAF and USN have different performance requirements for their combat aircraft
>>30648503
>not knowing why the USN turned down the F-16
>>30648171
that's false you fucking retard
>>30648429
The idea that a twin engine fighter has a higher t/w ratio is dependent on the aircraft/engine combination.
An F-35 out accelerates an F-16 despite having a ~50% higher empty weight.
>>30648478
>huehuehuehuehue
>>30648665
everything is false nothing is real.
>>30648464
From that angle, honestly it is. But from lower angles it looks like one of those Transformer toy jets that has a blocky robot body hanging off the bottom.
1 engine is cheaper and safer.
2 Engines have a higher failure rate but offer more thrust.
>>30648795
>2 Engines have a higher failure rate but offer more thrust.
Lower class-A mishap rate overall though. Two engines is ever-so-slightly safer if the engine isn't extremely reliable.
>>30648222
Russia went with dual engines because they're relying on "speed" to compensate for godawful RCS, and the airframe itself is too large for a single engine. That said, they're not making many of them so the point is kind of moot.
China went with two engines largely because their engine technology is absolutely fucking terrible and its required for them to have enough thrust.
>>30648814
>Two engines is ever-so-slightly safer if the engine isn't extremely reliable.
Modern western engines are. Almost all faults are down to maintenance.
>>30648839
Russia went with two engines because the PAK-FA is an evolution of the Flanker family.
>>30648854
>Modern western engines are. Almost all faults are down to maintenance.
The F-220 has a better safety rate on the F-15 than the F-16. I don't know why.
>>30648478
> the idiot grin of an exposed fan blade
>>30648839
And for them to stay in the air in case an engine goes out.
>>30648171
That was the Navy justification anyway. typically though one engine failure is catastrophic enough that it doesn't really matter.
>>30648431
It looks like a cheap whore with a prolapsed anus.
>>30648464
This looks like some fatass chinese "businessman" who's had one too many soup dumplings.
They both look like shit.
>>30648839
Also Russian engines are individually lower thrust. AL-41 is a decent bit bigger than F119 but produces less thrust, never mind compared to F135.
>>30648431
no it isn't
stealth aircraft design produces the most unattractive aircrafts
>>30650655
Objectively you have a shit eye for beauty.
>>30647905
> Could someone redpill me on single vs twin engine jet-fighters?
They're cheaper and offer higher weight to distance ratio. But they suck for thrust when compared to twin engine designs.
And then there's this:
>But the F-35 has one other serious liability, Kofman said—adding that U.S. Navy pilots are skeptical about single-engine designs. The F-35’s single Pratt & Whitey F135 engine—while immensely powerful, producing about 43,000lbs of thrust—also runs extremely hot. Unlike the Lockheed Martin F-22 Raptor, where the exhaust its F119 engines are flattened to reduce their infrared signature, the F-35 does not have any substantive measures to reduce the visibility of its exhaust from the enemy. The Russians—who build excellent infrared sensors—could use the F-35’s thermal signature to develop a weapons quality track to engage the stealthy new jet. “It’s probably has the hottest engine on the face of the planet,” Kofman said.
>Thus, the Pentagon’s fixation on a singular overly elaborate solution to a particular problem may yet come back to haunt it.
http://nationalinterest.org/blog/the-buzz/the-f-35-lethal-velociraptor-or-easy-pray-russia-or-china-16873
>98141305
The Pentagon has billed the Lockheed Martin F-35 Lightning II as the most advanced multirole fighter in its arsenal, but the most expensive piece of military equipment ever made apparently has a weak spot that could make it visible to newest air defense systems developed in Russia and China.
http://sputniknews.com/military/20160710/1042734198/f35-engine-radar.html
>>30648399
An engine failure in a single engine will lead to a crash
>>30651226
>national interest
>sputnik news
wow. he accidentally'd ALL the koolaide.
>>30651269
>debating where something's posted instead of debating actual arguments raised
go to bed, child. it's past your bedtime.
>>30650737
>American
I know you guys love to jerk off over "muh stealth", but at least older aircraft had character
>>30651302
>national interest
>sputnik news
>actual arguments
Is this your first day here?
>>30651304
your opinion is duly noted
>>30651302
>>debating where something's posted instead of debating actual arguments raised
Why would I bother to formulate a rational argument against biased crap that is sensationalized, exaggerated or downright fabricated?
Sputnik quoting RCS numbers on the F-35 is like an actual female past puberty describing Michael Jackson's dick. Never going to be accurate, because they've never fucking seen it. This is the same news outlet that claimed a Russian OTH radar system could generate weapons-grade target track. Over the fucking horizon.
As for the National Interest, Dave Majumdar should fucking know better than to suggest that the single F135 is somehow a larger IR signature than two F119s at similar thrust levels. It's absolutely ludicrous, especially when he's claiming the F119 exhaust is "flattened to reduce IR signature" and doesn't fucking bother to mention TV. Full fucking potato.
>>30651226
>hot engine meme
>nvm that the F135 has a higher bypass ratio, a nozzle cross section roughly equal to a single F119 nozzle and has a chined exhaust to mix hot and cold air quicker
>>30651251
Engines fail either due to birdstrikes (which statistically almost always happen within gliding distance of a runway) or due to unexpected engine failures.
Avoiding the former is up to luck and having good anti-bird systems in place. Avoiding the latter is down to having maintainers perform boroscopes, etc and correctly identify cracks in engine components. I've personally seen Super Hornet techs miss ~1" long cracks in afterburner flame holders (that I had to point out), all because there's a dozen or two per engine and it's not that hard to accidentally get them mixed up and not inspect one.
When you have twice as many things to inspect, the chance of not noticing a crack in a critical component goes up.
Some things just can't be avoided; no amount of maintenance can stop a pilot from exceeding airframe limits, or a 30mm shell from punching through an engine, etc. Maintenance is also generally set out by manufacturer recommendations; you can't fully rip apart an engine after every flight, so things like material defects can slip by and cause failures.
Ultimately though, the engine failure / crash statistics for modern, western single vs twin engine fighters indicates that there's little difference, with there even being cases like where there's been zero Class A mishaps for the F100-PW-229 in the F-16, but several for the F-15.
>>30651396
Majumdar regularly makes shit up, the cant fly with hot fuel and gun wont work till 2019 are my favorites.
>>30651396
>Sputnik quoting RCS numbers on the F-35 is like an actual female past puberty describing Michael Jackson's dick. Never going to be accurate, because they've never fucking seen it.
Shots fired!
>>30651226
Yeah, that is correct but if you had 2 engines it would probably the same without the nozzle improvement. Also there's the fact that they are not going to use full thrust all the time and that tracking is possible but engaging using IRST is not (at least in distances comparable to radar engagement).
>>30651302
I'm not the guy you're arguing with but reliability of the source is pretty important. I can make bad hypothesis that can't be proven correct or wrong and put them in a website, it doesn't make my claims anymore valid. Sputnik is not well known for its reliability. Regardless the argument in this reference is valid I think, so no problem.
>>30651369
>Is this your first day here?
no but it looks like it's yours. go back to plebbit since you're obviously from there.
>>30651396
do you even know who (((Mike Kofman))) is? obviously not you fucking retard.
and if you want more replies from me, debate the fucking facts.
IT'S A FACT that F-35 runs HOT. Hotter than any other airplane engine. It's sometimes looks hotter than Sun to IR sensors. And that's a fucking problem.
Now you can play the retard card and bitch about people who report these facts and you can stoop even lover and bitch about who covers it but it will not change the facts about F-35 engine running really, really fucking hot.
Stay mad, shit for brains.
>>30651548
>doubling down on defending shit tier blogs known for making shit up
wew lad, just wew
>>30651548
I like how you didn't actually address any of the anons refutations.
>>30651548
>IT'S A FACT that F-35 runs HOT. Hotter than any other airplane engine.
This is a difference between engine temperature, nozzle temperature and plume temperature, junior.
>It's sometimes looks hotter than Sun to IR sensors. And that's a fucking problem.
How, exactly, do you suppose a single F135 plume is somehow a larger IR signature than two F119s? Explain this to me, please. Both types have similar levels of bypass, both have chines, yet one system is pumping out literally double the thermal energy.
Please explain to me how the F135 is so easily detected when the F119, which the F135 is based on, is not. Further, please explain to me how any of this really matters from the frontal aspect.
>>30648464
Is not mig 1.44?
>>30651226
>>30651548
>F135 producing 28,000lbf dry (43,000lbf afterburner)
>F119 x2 producing 52,000lbf dry (70,000lbf afterburner)
>both with nozzle chine treatments
>similar bypass arrangements
>somehow F135 is hotter than the sun and F119 is super stealthy
Anon. Stop and read what you're typing for half a second.
>>30647905
It's not really a war if your planes work right and win all the time -- it's just a massacre. The F-35 will help us fight *wars* by allowing us to have enough losses/casualties.
>>30651702
The anti F-35 never cease to amaze me with the level of stupidity their fantasies delve to.
>>30651581
zero arguments from plebbitard, as expected.
>>30651610
>This is a difference between engine temperature, nozzle temperature and plume temperature, junior.
yes, and exhaust plume of a F-135 is the hottest of them all. the core is hot too but active cooling helps from melting the engine down.
>>30651610
>How, exactly, do you suppose a single F135 plume is somehow a larger IR signature than two F119s? Explain this to me, please. Both types have similar levels of bypass, both have chines, yet one system is pumping out literally double the thermal energy.
F-119 distributes the heat much better and it also has a much higher bypass ratio. F-119 also has longer length meaning that hot parts of the engine are further away from exhaust giving somewhat more time and space to cool the exhaust gases and even out the heat.
>really matters from the frontal aspect.
MUH FRONTAL ASPECT... jeez... how the heck do people still come up with this bullshit argument? Engagement exactly from the almost never happens in aerial combat.
There's also an issue with F-135 being the shittiest engine the US has ever produced.
https://defenseissues.wordpress.com/2014/12/06/fighter-aircraft-engine-comparision/
>>30651735
>The anti F-35 never cease to amaze me with the level of stupidity their fantasies delve to.
hello lockmart shill. $0.50 has been deposited into your account. thank you for shilling.
>>30651956
>MUH FRONTAL ASPECT... jeez... how the heck do people still come up with this bullshit argument? Engagement exactly from the almost never happens in aerial combat.
>HURR Stealth combat is never dictated by the lower RCS aircraft durr
>>30651956
>F-119 distributes the heat much better and it also has a much higher bypass ratio.
F135 actually has the higher bypass ratio. 0.57:1 vs 0.2:1 for the F119.
>F-119 also has longer
Nope. F119 is 516cm long. F135 is 559cm long. Next?
>There's also an issue with F-135 being the shittiest engine the US has ever produced.
>https://defenseissues.wordpress.com/2014/12/06/fighter-aircraft-engine-comparision/
Wow. You really don't understand what you're reading, do you?
This shit is just pathetic.
>>30648478
plebs, pure sex flying through
>>30652047
That looks too chubby and short. I like my planes long and thin.
>>30652037
>F135 actually has the higher bypass ratio. 0.57:1 vs 0.2:1 for the F119.
I'm not the person you are discussing with but can you give a reference to this figure? I think 0.57 is super high bypass for a fighter engine.
>>30652047
>manlets
When will they learn?
>>30652102
https://www.pw.utc.com/Content/F135_Engine/pdf/B-2-4_F135_SpecsChart.pdf
>>30652102
It's actually in his own source, for one.
>>30651956
>https://defenseissues.wordpress.com/2014/12/06/fighter-aircraft-engine-comparision/
>F-135: 0,57:1
For reference, the AL-31F and AL-41F both claim 0.59:1, the EJ200 has 0.4:1 and the F404-GE-402 is at 0,34:1.
>>30652121
That might include the lift fan as well. I need to check.
>>30651956
Your employer might want a refund if this is the best you can do for 50 cents a post.
>>30651956
The F135 holds the record for the hottest turbine inlet temperature, but that's it; the turbine inlet is the engine section between the combustion chamber / section and the turbine blades. Going through the turbine, the gases are expanded, cooling them, then it leaves the turbine and mixes with the bypass flow, of which the F135 has a lot of.
>>30652135
Oh wait, I'm wrong, it's the same for conventional.
>>30652135
0.57 for conventional, 0.56 for STOVL forward flight and 0.51 for STOVL vertical lift.
>>30651956
>yes, and exhaust plume of a F-135 is the hottest of them all.
No, it actually isn't. The F-35 has one of the highest bypass ratios of any operational fighter jet plus one of the longest engines and chine nozzle treatment. On dry thrust it's one of the cooler fighter IR signatures in the air.
Wow. Captain NatInt Sputnik got mighty fucking quiet.
>>30651251
If either of the two cause a crash, you've doubled your chances of crashing by having two engines.
Exhaust jets coming off of a twin engine setup has double the surface area compared to similar power output from a single engine and thus cools faster (i.e in shorter distance) to temperatures where it can't be detected. Shorter IR visible jet, closer the IR sensor needs to be to detect it
>>30652338
Wow. And the bullshit keeps rolling in.
Tell me, how is this applicable when the plume temperature of the F-22 and F-35 are close to identical, only the F-22 has TWO of them?
>>30652361
They actually aren't, if you put both engine configurations in similar cruise flight condition where they need to output 150kN for the plane to stay in the air the 2xF119 would be running at 48% power and F135 at 83% producing much higher initial temperature.
Even if we assume both type of setups would be producing identical volume of hot air coming out at identical exhaust speed and temperature it doesn't change the fact that two engines are less detectable because the jets themselves have double the surface area of a single larger one and thus cool down faster.
>>30652338
dude, you forgot to account the fact that the F-22 has *TWO* engines, doing engine things like running hot
>>30652479
Except that they're not going to be outputting the same amount for the same cruise condition; the F-22 is significantly larger and heavier than the F-35.
You're also still ignoring the fact that the F135 has nearly triple the bypass ratio and that very rarely will you be looking at a plume from exactly 90 degrees from its side. If the rear is facing you, the surface area doubles, if the jet banks, the surface area doubles, etc.
>>30652479
>where they need to output 150kN
Why would they both be needing to output the same thrust? They have different drag coefficients and weights. That's first.
Secondly, "initial temperature" doesn't mean anything in this context.
Thirdly, it's not double the surface area. The F135 has almost triple the bypass ratio compared to the F119, which means plume temperature is actually much, much cooler than an F119 running at the same thrust level.
>>30652479
Hey, I'm the guy who was asking about bypass ratios. If the bypass ratio is twice as much then operating at 83% wouldn't be an issue because comparably same amount of air is heated up and rest is bypassed. Also having more bypass means more cool air going around hot parts which would help it to cool down quicker probably.
>>30652570
>Thirdly, the F135 has almost triple the bypass ratio compared to the F119, which means plume temperature is actually much, much cooler than an F119 running at the same thrust level.
that's what that was supposed to say. my bad.
>>30652479
except the F-22 and F-35 don't weigh the same
>>30652570
I'm talking about two engines vs one engine, not the specifics of F-35 and F-22, they are inded different planes. But if we had a similar plane that could either be single engined or double engined and produce the same power output (even tho twin engines would be far easier to get more performance out) then the double engine one is going to be more stealthy in the IR.
>>30652649
I don't understand, they burn the same fuel, no afterburners are engaged, but somehow twin engine is stealthier? How?
>>30652649
here's the thing though, its easier to maintain one engine than two
logistics is vital in war
>>30652649
>then the double engine one is going to be more stealthy in the IR.
Even then the twin engined plane would have higher drag and more weight. That's an inevitability of adding more inlet drag and engine weight. That means your twin engine plane would have to produce more thrust/heat for the same speed.
This shit is nowhere near as cut and dried as you'd like to think.
>>30652649
>>30652689
Larger engines are also more efficient at producing bypass thrust; the proportions of your tolerances are allowed to be larger and things like parasitic drag don't scale as much.
Also again, this is working off the assumption that we're looking at the plumes from the side.
>>30652649
in addition to me in >>30652681
if you want to add a second engine, you have to have inlets and the weight o the engine itself
drag increases
now the engines have to run hotter
>>30652649
>I'm talking about two engines vs one engine, not the specifics of F-35 and F-22,
Really? Because that's what this discussion for the last 50 posts has been about. Don't let a little thing like inconvenient real world facts force you to move your goalposts around. That'd just be a damn shame.
Simple fact: the F-35 and F-22 have extremely similar engines (the F135 being a direct development of the F119), and the point you keep trying to assert just isn't true in real world applications. An F-15 does not have a smaller IR signature than an F-16. Shit, an F-18 doesn't have a significantly smaller IR sig than an F-16 - they're roughly equal. An F-4 burns way hotter IR than an F-8. And on and on.
>>30652678
Let me quote myself
>Exhaust jets coming off of a twin engine setup has double the surface area compared to similar power output from a single engine and thus cools faster (i.e in shorter distance) to temperatures where it can't be detected.
Increasing surface area of the exhaust jets was also the reason why they decided to put flat nozzles on F-22 even tho it has a significant performance penatly.
>>30652704
>Larger engines are also more efficient at producing bypass thrust;
The F135 is no larger in diameter and only 8.3% longer. That is not the primary reason it has a higher bypass ratio, junior.
>>30652749
>Increasing surface area of the exhaust jets was also the reason why they decided to put flat nozzles on F-22 even tho it has a significant performance penatly.
That's not even close to true. In any regard.
Seriously, where do you come up with this shit?
>>30652737
>it isn't true in real world applications.
In the real world F-35 can't even get past the sound barrier without AB while the F-22 can super cruise at Mach 1.8
>>30652749
>Increasing surface area of the exhaust jets
>flat nozzles on F-22
>significant performance penatly.
Holy fucking shit, anon. You have planted a flag in the undiscovered country beyond full retard. How's the view?
>>30652777
Oh, look. More irrelevancy. Wonderful. I thought we were discussing standard combat cruise speed. Unless you're suggesting the F-22 in supercruise is somehow a smaller IR signature than an F-35 cruising at .8 mach. Because that would be absolutely hilarious.
>>30652777
dude the f-35 can go mach 1.2 without afterburner
>>30652752
I'm talking about the generic example that >>30652649 was talking about.
>>30652777
The F-35 can do Mach 1.2 without afterburner; both jets are also primarily going to fly at around Mach 0.9; even an F-22 supercruising burns around 1.5x as much fuel as if its flying subsonic, hence why its mission profiles only have it supercruising for 100-200nmi.
>>30652827
>I'm talking about the generic example that >>30652649 was talking about.
No, you're samefagging >>30652649
and >>30651956
and trying to pretend you're different people because you keep getting facefucked with facts.
>The F-35 can do Mach 1.2 without afterburner; both jets are also primarily going to fly at around Mach 0.9; even an F-22 supercruising burns around 1.5x as much fuel as if its flying subsonic, hence why its mission profiles only have it supercruising for 100-200nmi.
aaaaaaaand more irrelevancy.
>>30652852
Why would I be samefagging when I'm debunking his argument?
>aaaaaaaand more irrelevancy.
In what way? Or, as >>30652820 mentioned, are you suggesting that a supercruising F-22 has a smaller IR signature than an F-35 subsonic cruising?
>>30652820
No, that just shows that when F-22 and 35 are both cruising at that .8 the F-35 is going to be using using most of its dry thrust capability while the pilot of that twin engined F-22 has hardly touched his throttle
>>30652821
"while technically not super cruising"-cruising
>>30652893
>No, that just shows that when F-22 and 35 are both cruising at that .8 the F-35 is going to be using using most of its dry thrust capability while the pilot of that twin engined F-22 has hardly touched his throttle
and their IR sigs will still be roughly equal. remember that little triple the bypass ratio detail?
>>30652893
>In the real world F-35 can't even get past the sound barrier without AB while the F-22 can super cruise at Mach 1.8
>dude the f-35 can go mach 1.2 without afterburner
>"while technically not super cruising"-cruising
I still don't understand
if you're going mach 1.8 how exactly is that IR stealthy
![V58Fmdy[1].png](https://i.imgur.com/6bzfotH.png "V58Fmdy[1].png")
>>30652893
The discussion wasn't whether the F-35 could supercruise, it was whether it could break Mach 1 without AB, which it can. It's only "technically not supercruising" because Mach 0.8-1.2 is considered transonic.
An F135 supposedly has a SFC of 0.87lb/lbf. That means at max mil power it'd consume 24,000lb of fuel an hour. And yet, it only consumes about 4000lb per hour to cruise at Mach 0.75 (see pic). An F-35 cruising at Mach 0.8 is hardly using "most of its dry thrust capability".
>>30652821
The peak drag is at 1.0 however, maybe it can get past that by flying high and then coming down using gravity to assist it past the barrier without actually touching the AB, but in the real world that would just be silly. Use the AB, get past the barrier to your desired 1.2 and leave the AB at minimum setting and do the "technically not supercruising"-cruising 100 mile dash
>>30647905
More TORQUE.
>>30652047
Reminds me of that mini plane from spy kids.
>>30653027
The coefficient of drag peaks at about 1.0, but not total drag force.
>>30648399
This is so fucking wrong it hurts.
>>30652940
>it was whether it could break Mach 1 without AB, which it can.
wrong
>>30653114
According to you
>>30653125
Looking at the fact that you didn't provide anything that could back up your claim. You just pulled out some shit out of your ass.
Supercruise is also differently defined.
>>30650280
What are you talking about? Rhinos have no problem flying and landing single engine.
>>30653102
statistics say its correct
>>30653182
What statistics?
>>30652940
Your analysis fails to take into account the affects of high altitude on aircraft performance. Any aircraft engine will perform more efficiently at higher altitude up to a point. An extreme example is the F118-Ge-101 found in the U-2S. The engine produces more thrust at sea level and the idle throttle than it does at maximum throttle at the U-2's typical cruising altitude of 60+ thousand feet. For best supercruise performance the F-22 likely climbs to around or above the altitude a commercial airliner flys. It could probably do it at lower altitude but the fuel burn makes this inefficient as fuck.
Two engines also means twice the maintenance and failure rate :^)
>>30653824
>Two engines also means twice the maintenance and failure rate :^)
An engine failure is an engine failure. It's a beginning, but not the end, of an incident.
>>30653893
It goes a hell of a long way to ending an incident though.
>>30652940
>because Mach 0.8-1.2 is considered transonic.
fucking lel, no
>>30651226
>The Russians—who build excellent infrared sensors
lol
>>30654232
http://history.nasa.gov/SP-367/chapt5.htm
>NASA
>Additionally, transonic flow pertains to the range of speeds in which flow patterns change from subsonic to supersonic or vice versa, about Mach 0.8 to 1.2.
>>30654470
NASA is about space not atmospheric flight, retard
>>30654606
>space
>speed of sound
>>30648632
>F-16N
are you retarded?
>>30648795
more thrust, more maintenance.
>>30654641
Theres no sound in space, so how is the speed of it relevant
hello????
>>30653597
>above the altitude a commercial airliner flys
Why would it in any way even be worthy of comment that the F-22 is operating above 35,000 feet? Also, the U-2 flew well above 60,000ft.
>>30648171
This pretty much sums it up.
The balance is making sure they're close enough to not be a yaw issue on a single-engine approach, yet far enough to prevent a catastrophic failiure take both engines (and therefore, the entire aircraft) out.
>>30654606
national AERONAUTICS and space administration
>>30648171
Yep.
When one fails, you can fly all the way to the crash site with the remaining one.
>>30652649
2 F119 are much much heavier and harder to fit onto an airframe than 1 F135.
If you want an actual comparison between 1 and 2 engine, compare 2 F414 to 1 F135. Both produce similar amounts of thrust, but F-135 is considerably lighter than 2 F414.
>>30654812
While I'm not supporting the retards still living in the era of 1960's fighter engine design and the reliability issues thereof, the following should be noted:
In case of a catastrophic engine failure which does not spread shrapnel, fire or cause fuel feed or other systems failure to the other engine (relatively rare in case of combat damage):
>portion of the flight regime matters, as does engine nacelle distance from centerline
The reason for this is simple, and can be demonstrated with two different situations. Consider a single engine failure while on carrier landing approach and a single engine failure at 40,000ft.
In the case of the high altitude failure, a pilot is not immediately forced to pour on power to the remaining engine, instead he may trade altitude for speed, gradually ensuring sufficient velocity to maintain control of the aircraft while addressing warning lights, shutting the damaged engine systems down, trimming for asymmetrical thrust and then slowly bringing the remaining engine power up while adjusting trim.
On landing, the pilot's only immediate response can be to pour on remaining power while fighting the yaw resulting from asymmetrical thrust and dealing with the engine emergency.
Further, note that how far the engine nacelles are offset from aircraft fuselage centerline affects just how dramatic this induced yaw is. In the case of the F-18, the yaw is significant, but still very manageable. In the case of the F-14, it is massive. Add the F-14's problems with compressor stalling, and the pilot's instinctive response to increase engine power in the remaining engine can so dramatically upset yaw control that a flat spin is induced before the aircraft is stabilized in the immediate aftermath of an engine loss. This is why so many F-14As were lost, and why the F-18 and F-15 have generally fared well in non-destructive engine loss scenarios.
cont
>>30654812
>>30655080
>engine offset from centerline also affects the chances that both engines will be damaged in case of catastrophic engine failure
This consideration is something of a no-brainer. The closer the engine nacelles are to each other, the greater the chance that a mechanically catastrophic engine failure (kaboom, parts explode through housing) or fire will immediately affect the other engine. In this, the F-14 is clearly far better off than the F-18 or F-15, however it is important to note that catastrophic failures like this tend to cause enough damage to surrounding systems to cause total aircraft loss regardless of damage to the remaining engine.
>>30655084
Except in the F-14, the wide engine stance caused flat spins on single-engine flameouts, which happened a lot on the TF-30s.
>>30654705
The F-22 (or any other tactical fighter for that matter) can operate anywhere between sealevel and 60,000 feet. I could have been talking about operations at lower altitude where increased air resistance reduces efficiency.
Additionally with all the payload attached , a U-2 will typically cruise between 60-70,000 feet. Hence the 60+ thousand feet. In either case are you going to argue that anything I have said is false?
>>30654987
A better comparison might be with the F100-PW-229, which powers both the F-15 and F-16, or in simply comparing F-16 and F-18 characteristics.
>>30655080
>>30655084
As a final note, some points to consider:
>the USN prefers twin engine aircraft not primarily because of the enhanced reliability granted by not having to rely on what in the 1960's were still new and relatively fragile jet engine technologies. Engine spool up time or throttle response was a huge consideration.
A simple fact of early and even most current jet engines is this: the larger in diameter they are, the less responsive they are to changes in RPM. This goes back to the simple physics of a rotating mass: the further out from the circle the mass is, the more inertia resists changes in rotation speed. Build a wider engine, you get more overall power, but the engine is slower to respond.
One of the biggest USN problems with carrier ops and early jets was their sluggishness in response to throttle change commands, which on landing during a wave off is pretty crucial. This is a large part of the reason early USN carrier jets were so underpowered in normal flight regimes - their engines were diameter limited to maintain arrest operations responsiveness. It's also one of the reasons the F-8 features a variable-incidence wing - lower stall speeds mean more time to power on with the larger, more powerful engine. Moving to the dual engine F-4 provided a stopgap until larger engines could be built with better throttle response, the J79 being slightly smaller diameter but still much more responsive than the J57.
cont.
>>30655080
>>30655084
>>30655246
The use of modern aircraft engine composites and turbine blade construction has gone a long, long way to alleviating this issue. Even though the F135 (F-35) has a 31.4% larger diameter than the F414-400 powering the F-18E/F, throttle response is only slightly more sluggish than the F-18E/F, which already has one of the most responsive engines in modern fighter aviation (about 4 seconds from idle to full afterburner).
A single engine provides benefits in significantly decreased maintenance, lighter, smaller aircraft (a premium when considering supercarrier and LHD/LHA deck space) and a reduction in maintenance-caused mishaps. Add in excellent throttle response, and the only real advantage to twin engines lies in the significant but not exactly overwhelming chance of aircraft recovery in case of non-catastrophic engine failure discussed here >>30655080 and >>30655084. At this point it becomes an actuarial decision between the added cost of maintenance per flight hour and extra maintenance personnel plus the extra cost of double engines and the slightly higher chance of a class B mishap becoming a class A (historically about .4-.6 class A mishaps per 100k EFH).
>>30655224
>Except in the F-14, the wide engine stance caused flat spins on single-engine flameouts, which happened a lot on the TF-30s.
That's exactly what I noted just above that post here >>30655080
>In the case of the F-14, it is massive. Add the F-14's problems with compressor stalling, and the pilot's instinctive response to increase engine power in the remaining engine can so dramatically upset yaw control that a flat spin is induced before the aircraft is stabilized in the immediate aftermath of an engine loss
>>30655232
>In either case are you going to argue that anything I have said is false?
I would point out that an F-22 is very rarely going to be supercruising at less than 48,000 feet, considering it is optimized to supercruise at 52,000ft+. It seems very, very odd to mention supercruise and airliner altitudes in the same sentence when considering the F-22.
>>30655276
There are uninformed people on /k/ who won't use Google and think an F-22 can supercruise at sealevel.
>>30655246
F135-PW-100 x1: 28,000lbf mil, 43,000lbf AB
F414-400 x2: 26,000lbf mil, 44,000lbf AB
F100-PW-229 x2: 35,600lbf mil, 58,320lbf AB
F414s are a better comparison.
>the larger in diameter they are, the less responsive they are to changes in RPM.
Before someone tries to half-assed rebut this, it is correct, one neat thing about the F-35 and Super Hornet is their new Delta Path and MAGIC CARPET flight software, where the computers control airspeed and lift through the control surfaces first. So during landing, the engine will throttle up extra, but the surfaces will be in a partial spoiler configuration. If the pilot demands more throttle, it streamlines to instantly reduce drag while the engine spools up. Apparently it (and other features) make carrier landings significantly easier and safer.
>>30655379
>F414s are a better comparison.
But there is no single engine F414 example to compare against. With the F100-PW-229, you can compare flat characteristics and the benefits/costs/mishap rate differences between single and twin engines (F-16 vs F-15) while not having to deal with two different engine designs which might have different MTBO, mishap rates, requirements, etc. You don't even have to adjust between different engine performance characteristics. You only have to account for different airframe issues and other outside factors (admittedly substantial with the F-16 inlet/stall issues and the early F-15 reliability issues fueled by O&M funding shorfalls). The heart of comparative scientific analysis is making as many variables as close to the same as possible when considering the question, which in this case is "are two better than one, and if so how?"
>>30655379
>their new Delta Path and MAGIC CARPET flight software
I wasn't aware of this. Cheers. Reading up now. Seems pretty slick, but doesn't this reduce control surface responsiveness and overall lift while they're trying to power on? Or am I missing a key part of the equation?
>>30655485
Mishap rates sure, but I thought we were talking about thrust levels, IR output and diameters?
>>30655503
If it does, it's not going to be noticeable; because the workload is much lower, it's far less likely for the pilot to need high responsiveness / that much lift anyway. This video explains it: https://www.youtube.com/watch?v=X-pWG4T65f0
>>30655379
>>30655503
Slightly off topic, but as I'm reading about this, I wonder if anyone knows where I can find Cooper-Harper handling qualities ratings for modern fighters? It'd be much appreciated.
>>30655569
Actually, better explanation here: https://www.youtube.com/watch?v=IGVsrNW7bgU
>>30655569
>I thought we were talking about thrust levels, IR output and diameters
Well, it seems to me that if the engines are exactly the same in thrust levels, bypass ratio, and IR output (but regrettably not nozzle in this case) given similar throttle levels plus the diameter is identical, then the above anon's claims of more surface area with two engines plus lower throttle automatically equals smaller IR signature would be easier to explore. I think most anons reading this thread understand that the issue is much more dynamic and complicated than the above anon suggests, but it's still worthwhile to keep as many variables static between systems when comparing.
In this case, I'm not sure anyone is going to argue that the F-16 has a larger IR signature than the F-15 except at very specific flight speeds and altitudes. Overall, the F-15 does present a larger signature in most situations, just as the F-4 presented a more substantial IR signature than the F-8 in Vietnam in most cases.
>>30648301
They had to choose two engines because they were unwilling to end up with a fat piece of shit that can't supercruise and has Mach 1.6 upper speed limit.
>>30655610
that's pretty fucking slick
>>30654987
F135 is way never tech making that comparison pretty moot
>>30647905
Well, the single engine fighters only have one engine, and the twin engine fighters actually have two!
>>30655610
And footage of what DFP looks from the outside: https://www.youtube.com/watch?v=3BOt0a_tGRg
>>30655602
You'd have to do individual searches for every plane, but I managed to find ratings for the F-35B during vertical landings:
>On the Cooper-Harper rating scale used by test pilots to evaluate handling characteristics, pilots gave an average rating of 1.77 for descent and 2.28 for landing in baseline vertical-landing mode. For the TRC mode, pilots rated descent at 1.52 and landing at 2.04. The scale ranges from 1 to 9, with 1 representing excellent characteristics and a low workload task and 9 representing major deficiencies and intense pilot compensation required to maintain control….”
http://www.f-16.net/forum/viewtopic.php?f=22&t=16196&start=60
In normal flight the F-35 has a program requirement to have:
> Aerial refueling and landing at the original/alternate destination with Level 2
(or better) handling qualities. Cruise and descent with Level 3 (or better) handling qualities. Terminating precision tracking or maneuvering tasks with Level 3 (or better) handling qualities.
http://www.aviationsystemsdivision.arc.nasa.gov/publications/shaq/NASA_Pub_2009_Bailey.pdf
>>30655689
Also, this goes to show how good Magic Carpet / DFP are:
>Both the basic F/A-18E/F and F-35C flight-control systems had provision for direct lift control, but the innovation in Magic Carpet is to add the Delta Path mode. In simulator tests at BAE Systems’ Warton, England, site, the workload for an F-35C carrier landing was reduced from a Cooper-Harper handling qualities rating of 6 (extensive pilot workload), to 2 (minimal pilot workload), according to a Navy document.
http://aviationweek.com/defense/flight-control-advances-promise-big-savings
>>30648464
It looks like a stupid fanart.
As someone who worked in the Program Office for the F135, this whole thread is full of knee slappers and misinformation.
That said, if you want to find the inherent weaknesses with the F135, look at the Adaptive Engine Transition Program and the variable bypass ratio work they've done.
>>30655647
>They had to choose two engines because they were unwilling to end up with a fat piece of shit that can't supercruise and has Mach 1.6 upper speed limit.
This might be remotely correct if the J-31 weren't so laughably underpowered. The MTOW T/W ratio for the J-31 with the current RD-93s is .69, and that's if they're not fudging weight numbers. Remember, this is on an aircraft which weighs 15,000lbs less than the F-35A, which has a MTOW T/W of .61 with nearly double the useful payload of the J-31. In just maximum internal fuel T/W terms, the F-35 is sitting at .87 and the J-31 is at roughly .78 (can be refined as more precise data becomes available - they're still deep in prototyping and things are changing). Empty T/W works out to 1.48 for the F-35, roughly 1 for the J-31 (again, pending final specs).
The Chinese are forced to use the RD-93s because they do not yet have the tech worked out for their WS-13A, and there is no indication yet when they will have those finished. So far it is a pretty massive disappointment. They are nowhere close to the tech require to produce the F135 either in power or MTBO. Their WS-13A, even if it performs exactly as designed (doubtful), will still only be half the power of the F135 with less than half the MTBO.
>>30655689
>And footage of what DFP looks from the outside
Goddamn that's cool
>>30655777
>This might be remotely correct if the J-31
No one fives a fuck about gook copycats.
>>30655753
Does your dad also work at nintendo?
It's not like variable bypass hasn't been an integration goal in fighter engine design for two decades, and isn't a major milestone for Gen 6 fighters.
>>30655791
Considering the fact that they're pretty close to catching and then passing Russia in aviation engine design and production, maybe you Vodka sponges should give a fuck about them.
>>30655485
> But there is no single engine F414 example to compare against
uhh, Gripen E/F?
>>30655870
F414G. Which has been modified.
>>30655817
>they're pretty close to catching and then passing Russia in aviation engine design and production
This is what gook shills actually believe.
>>30655689
>You'd have to do individual searches for every plane, but I managed to find ratings for the F-35B during vertical landings:
Cheers. I was immediately interested in a comparison of HQRs between gen 4 NATO and Soviet fighters, test the hypothesis that in the 1980's and 90's Soviet pilot workload in combat (including managing sensors and weapons) was generally much higher than NATO counterparts. Guess I need to do some digging.
>>30656015
Considering the amount of money, espionage and skilled labor/research they're putting into it, it's only a matter of time compared to Russia's vastly reduced funding. Also,
t. Burger
>>30647977
An F-16 has a higher top speed than a Hornet, despite being only a couple years apart and having similar roles.
A Starfighter and Thunderchief (single engine) are both faster than a Voodoo (twin engine)
There's a lot more to consider than just number of engines.
>>30656031
Considering that in the end they can't even copy old Soviet engines, it's only a matter of gook shills trying too hard on the internet.
>>30656051
Conflating "currently behind" and "will never catch up despite evidence to the contrary" is a recipe for the repetition of such historical classics as Tsushima, USS Constitution vs HMS Guerriere, Surigao Strait or the Second Naval Battle of Guadalcanal, etc. It's lazy analysis and thinking.
>>30656091
Only evident thing here is a gook shill trying too hard on the internet.
>>30656126
And this is why Tsushima continues to be so hilarious.
>>30656138
No, it is why gook shills keep trying too hard on the internet.
>>30656032
>top speed
possibly the most meaningless metric in existence in this context.
>>30656171
I'm so tempted to keep poking him and hope he kicks off a vatnik-chicom shitstorm, then make some popcorn and sit back to watch.
>>30656189
he was replying to a post saying that twin-engine aircraft are faster than single engine.
nothing he said was wrong
>>30656318
Its an intentionally misleading metric.
An F-16 may be marginally faster than an F-18 at high altitude (130kts) but its the same speed at lower altitude.
Furthermore, it becomes far slower as soon as it actually starts having a useful payload, because an AIM-9/AIM-120/Drop tanks/LITENING pods and their inherent parasitic drag effect the larger, heavier aircraft with more thrust a hell of a lot less than they do the light aircraft with a single engine.
Nobody gives a shit about airshow performance, and thats all top speed is; performance when clean and practically useless.
