Forum: General F-35 Forum

'QS'

You forgot the OzTrailians amongst some others missed (Spanith, Eyetalians, CanUKians). Big No No

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Scorpion82 wrote:

sewerrat wrote:

All I know is that John Beesley has stated that the -35 is on par with the -16 in turning and accelleration; and that the -35 is on par with the -22 throughout the subsonic region. As others have said, looking at "static" t/w and wing loading numbers doesn't a prediction make about performance.

The initial variant of that big PW engine isn't going to be the same throughout the life cycle of the -35 either. We may well see a 50,000lb thrust version before its said and done. That should up the ante, so to speak. I don't think the -35 is as big as a slug and is purported by those just looking at wing loading and t/w numbers.

Such claims must be put into the perspective. The F-35 may match the performance of the F-22 in a very few areas subsonic, but it certainly won't across the board. A relatively large frontal cross section stemming from the requirement to carry stores and a lot of fuel internally in such a compact aircraft, a clearly higher wing loading and inferior thrust weight ratio, lower sweep angles, no TVC, smaller control surfaces etc. It's ridiculous to believe that the F-35 could match the performance of the Raptor overall in most areas. Sure it will turn as well as other aircraft at high speeds with 9 g at lower altitudes and it may not be much worse when it comes to sub sonic acceleration, but anything else is physically nonsense in comparison to the F-22 at least. In comparison to legacy fighters it will enjoy advantages in some areas due to the internal carriage of weapons and a lot of fuel and that's what matters in the end. But this also depends on the exact configuration of the aircraft and neither aircraft can overcome the natural physical laws.

What does a large frontal area have to do with any thing??? If you know anything at all about aerodynamics it is what you do to the back end of the object that has more effect that then the front end.

Well, one can put their aircraft purchases down to other reasons (F-35's strong lobbying from the US government; stealth, who doesn't like stealth; etc.)

I get that the F-35 is probably better than the F-16 in equivalent combat configurations. What we don't know is whether or not that is sufficient for the modern environment.

I find the CONOPs behind the F-35 quite interesting, it is sort of an improved variation of the F-117 flight pattern (subsonic, medium altitude) but with improvements in sensors. It will be fascinating to watch those CONOPs change as the technology advances on the defenses side. Eventually, the F-35's stealth will be "moderate" or "minimal" compared to deployed sensor technology; what will the F-35 do then? (The F-70 advertisement: unlike legacy F-35 technology, this airplane doesn't need a full strike package to penetrate enemy airspace)

What a sad comparison 'arkadyrenko': "...I find the CONOPs behind the F-35 quite interesting, it is sort of an improved variation of the F-117 flight pattern..." My definition of 'improved' is a lot more robust.

@arkadyrenko...... Don't forget that the F-35's bag of tricks is going to grow much larger as she matures. So advances in electronic warfare, active stealth, stealth coatings, and weapons can all be expected.

alloycowboy wrote:

What does a large frontal area have to do with any thing???

Everything.
(Shame, no Yoda icon Very Happy

)

quicksilver wrote:

The F-35 is not the 'dog'...

Among fighters, it is.
DoD don't think it's a problem though, which is entirely different thing...

alloycowboy wrote:

What does a large frontal area have to do with any thing??? If you know anything at all about aerodynamics it is what you do to the back end of the object that has more effect that then the front end.

The frontal cross section is part of the overall drag equation and the width/length ratio is relevant as well. Physically the F-35 isn't that much larger than an F-16 and it has about 50% more thrust at its disposal. The F-35 yet "just" matches the acceleration performance of a clean F-16 blk 50 which suggests that it is a fair deal draggier, but compensates for it with more thrust. The thrust is also required to cope with the higher weight, but the TWR is in fact less relevant for acceleration performance than the thrust/drag ratio and the latter is in part dependent on the frontal cross section.

quicksilver wrote:

A little perspective --

Jon wasn't providing a detailed performance comparison; he was asked to give his general impressions of F-35 up-and-away performance (given that he had flown F-16, F-22 and F-35). At the altitude that the USG has chosen to assess subsonic acceleration, a combat configured (once again, with a USG-specified internal load) F-35A is very comparable to F-22. It may or may not be comparable to F-16 acceleration depending on what one chooses to characterize as a combat load for the F-16, since the F-16 cannot come close to matching F-35 missions systems capabilities without hanging a T-pod, an HTS, and an ALQ to the tune of significant increase in drag index and consequential decrease in accel and turn capability. In the most common configuration that Vipers go to war with (not the made-up stuff in blogs nor the fun stuff often flown/trained with in the Restricted/Warning Areas), the F-35 is easily better in a wide range of performance measures.

Of course, that's also before we start talking about fuel capacity and range. A clean F-35A has ~9200# on board at 50% fuel -- without the drag penalty of external fuel tanks. If the Viper is not carrying external fuel (which means it's not in a combat configuration), it has about 3500# of JP on board at the 50% fuel number. That translates to "less" in a lotta different aircraft performance measures where "more" is not just 'better,' but decisively so. And for those of you who believe that external fuel tanks are dropped a la those wonderful WWII pics of P-51s over Germany, think again. It rarely happens, and usually only in the context of an IFE. You're certainly not going to pickle the T-pod, the HTS, or an ALQ.

The F-35 is not the 'dog' that detractors routinely suggest. Nor is it an F-22 (aerodynamically). But, combat configured, it is a significant advancement in overall capability compared to the jets it was designed to replace. Think about it -- do we really think the USAF, the USMC, the USN, the UK, the Israelis, the Dutch, the Turks, Norway and Japan are that stupid?? Come on man... Cool

A well considered reply, just one premier point. The three times larger fuel quantity doesn't translate into a three times longer range and endurance as the F-35 will guzzle fairly more fuel with its much more powerful engine. The advantage is certainly there, but if we look at about twice the range it's already good.

arkadyrenko wrote:

Eventually, the F-35's stealth will be "moderate" or "minimal" compared to deployed sensor technology; what will the F-35 do then?

Oh now come on, with updates (not included in the current funded costs), it's going to be viable into the 2060s, haven't you heard?

"A well considered reply, just one premier point. The three times larger fuel quantity doesn't translate into a three times longer range and endurance as the F-35 will guzzle fairly more fuel with its much more powerful engine. The advantage is certainly there, but if we look at about twice the range it's already good."

Max range Mach number for F-35 is very high and it fairly sips gas at that number. There are also some intentionally conservative ground rules and assumptions in its combat radius performance.

Some of this reminds me of Spitfire v Mustang 'which dog is bigger' discussions. Much to be argued over which one was better over northern France. No question about which one was better over Berlin...

redbird87 wrote:

arkadyrenko wrote:

Eventually, the F-35's stealth will be "moderate" or "minimal" compared to deployed sensor technology; what will the F-35 do then?

Oh now come on, with updates (not included in the current funded costs), it's going to be viable into the 2060s, haven't you heard?

You mean besides evolve? I guess they'll have grind up the fleet into little bitty carbon fiber scraps.

One other thing people aren't looking at in turning performance of the -35 is control surface placement. Look at the -16 compared to the -35, the horiziontals are positioned further aft of the fusealage... The fusealage appears to be shorter than the -16, and the -35 should excellent pitch control. Just another example of you guys worrying about "kinematic performance" needing to look at a lot more than just wing loading and t/w to "calculate" how well it turn in a fight.

SpudmanWP wrote:

If supercruise is a byproduct of having a clean airframe and a high thrust engine (both are design requirements) then nothing was "added" to make it supercruise and therefore no money was wasted.

I agree completely, but congress, politiciants, ext. likely will not see it that way, or will choose not to see it that way to support whatever their current campaign is. I can hear the McC's, or any number of others now, "Lockheed Martin stole taxpayer money to add additional "gold plating" to this already over priced, over weight, late, . . . program. We never asked for this and LM forced it on the taxpayer." (forced on us, like ObamaCare, and Social [in]Security? but that is an entirely different issue, and a different website for that matter). While in reality like you said, it is more likely a byproduct of the design than something they designed into the aircraft, thus my "Dumb as that sounds" statment.

Sufa Viper

Quote:

What a sad comparison 'arkadyrenko': "...I find the CONOPs behind the F-35 quite interesting, it is sort of an improved variation of the F-117 flight pattern..." My definition of 'improved' is a lot more robust.

Its more robust in the sense that the fighter has much greater kinematics and has better sensors, but the general idea is exactly the same. Operate at high subsonic above the range of SHORAD systems and rely on stealth to carry the aircraft through threat regions. That hasn't changed between the two versions. I'm not sure what else changes between the F-117 and the F-35, in the strike role.

Quote:

@arkadyrenko...... Don't forget that the F-35's bag of tricks is going to grow much larger as she matures. So advances in electronic warfare, active stealth, stealth coatings, and weapons can all be expected.

First, have fun fitting that into an airframe already near maximum weight and with internal cooling problems. Here we have the basic issue with stealth, its hard to get upgrades for it.

Even with a robust upgrade scheme, the marketers will still have something to say: "unlike the F-35 blk 1000, the F-70 has all the electronic capabilities, and more, fully integrated into the airframe." I think that redbird said it best, some people here act as if the F-35 will stay on top through its service life, with the planned upgrades. That has not happened to the F-4, that has not happened to the F-16, and it will not happen to the F-35. (Oooh, who is going to fall for the logical trap I just laid...)

Back to my original point, it will be interesting to watch the F-35's CONOPs change as its stealth advantage shrinks. Will "nap of the earth" flying return if a combination of heavily defended low frequency search radars and bistatic arrays degrade stealth to the point where it can be easily located (perhaps not for attack, but for intercept)? Or, will the F-35 take some alternate attack route / tactics; a return to teen series SEAD + strike combos?

ps. what active stealth?

Wanna see a dog?

Hang EFT and weapons on a 4th gen so it can actually do A2G.

Comparing a clean F-35 to a clean 4th gen is pointless.

arkadyrenko wrote:

Back to my original point, it will be interesting to watch the F-35's CONOPs change as its stealth advantage shrinks.

Why will it's stealth advantage shrink? Why won't new models be stealthier than the first gen -35? For one, coatings will or can in theory improve. Secondly, materials can most definately improve. For one example, there's been fairly recent discoveries made in (for lack of a better word) nano-surface treatments which can render lower radar returns on even sheet metal. What the -35 is today, isn't the -35 of 10 years from now. Why does everyone assume the program is going to be stagnant in R&D once the line gets moving? The -16s rolling off the line today sure ain't nothing like what was coming off the line in 1984.

Forum: General F-35 Forum

F-35 Kinematics in Air to Air configuration