F-35B vs Harrier

[Abraham Gubler]

The concern about "AWACS killing" missiles seems real enough, and honestly when talking about the E-3 or YAL-1, they are based on airliners. And how long can the chemical "battery" of the YAL-1 allow the laser to be fired?

They are based on airliners, they aren’t airliners! The difference is a little thing called situational awareness, ie the knowledge that someone has fired a missile at you that will take five minutes to get close enough to do any damage. Not to mention air force training, tactics and so on. No one in the AEW&C community is worried about these missiles. In the time of flight of the AWACS killer their targets can evade and defeat the threat. Which is why missiles are talked of in relation to no-escape zones which is the range from within the target can’t escape. Such a zone is determined by missile kinematics and fire control.

Look at the position proposed for such a laser turret beneath where the lift-fan would be on the F-35A and F-35C. I doubt it can cover behind the aircraft, and I don't know if there would be room for a top laser turret as well.

So I guess we’re all lucky you aren’t on the design engineering team for such a solution? Even if said laser can’t penetrate the exterior mould line it should have no problem providing a near complete full spherical firing solution. There may be some gaps from the tails and wings and so on but since they are so small they can easily be compensated for by minor movement of the aircraft’s attitude. Since targeting and flying is controlled by a computer such minor adjustments could be carried out automatically without need for the pilot to get involved.

I didn't say the F-35 wasn't agile enough, however I do believe incorporating a TVC nozzle at a later date, like that being tested for the Eurofighter would be a welcome addition, and not just for maneuverability reasons. Yet even for ground attack you want speed to be able to respond quickly and minimize your exposure to enemy fire. Plus you want a better turn capability than say a SR-71 or C-17.

You’re just reading from a catalogue. Why bother with TVC when you don’t need that sort of agility for lethality or survivability purposes. TVC isn’t going to make your aircraft a better ground attack platform.

And who said the F-35 has a turning circle of a SR-71 or C-17? Why waste everyone’s time with such factless bile. Besides I’ve been a C-17 that turned pretty damned tightly…

Regarding the F-35 air-to-air capabilities, without AIM-9X internal carriage it really lacks the ability to take advantage of all of the situational awareness systems at close range, at least until a new missile is fielded.

A new missile is being fielded. Further this kind of argument doesn’t take into account a range of other issues. For example how is the engagement geometry going to get within the AIM-120D’s HOBS envelope so an AIM-9X is needed? The F-35 doesn’t need to manoeuvre to engage then it will stay high energy. So how is someone going to get through its AIM-120D engagement envelope and up close so an AIM-9X is needed? Teleportation?

Until such advanced laser systems emerge, I don't think we will see the demise of the dogfight. With sufficient numbers of 4.5 and 5th generation fighters, it is unlikely an enemy flying Migs and Flankers for example will get that close. And if you have some AIM-9Xs or IRST-Ts your probably won't use that gun.

No one said the dogfight is going to disappear. Just that it will be fought differently. This is a classic case of everyone has an opinion no matter how ill-informed it is.

 

[AeroFranz]

I think we have hijacked the "F-35B vs Harrier " thread long enough (I include myself in the hijackers!). I would like to continue it, but in the interest of keeping the forum organized I'll ask the moderator to move this to its own thread.

 

[Colonial-Marine]

They are based on airliners, they aren’t airliners! The difference is a little thing called situational awareness, ie the knowledge that someone has fired a missile at you that will take five minutes to get close enough to do any damage. Not to mention air force training, tactics and so on. No one in the AEW&C community is worried about these missiles. In the time of flight of the AWACS killer their targets can evade and defeat the threat. Which is why missiles are talked of in relation to no-escape zones which is the range from within the target can’t escape. Such a zone is determined by missile kinematics and fire control.

I believe the YAL-1 could be a very useful asset if it was patrolling with an AWACs and the usual accompanying fighter support. However I wouldn't advise sending one on it's own way. Regarding AWACS killers, can't the missiles being proposed for this role be guided by a supporting radar, a ground based system or enemy AWACS for example? Don't they also have an anti-radiation mode where the home in on the radar? I may be reading too much into Russian hype but even if they wouldn't be able to take down an AWACS it could cause some temporary problems.

So I guess we’re all lucky you aren’t on the design engineering team for such a solution? Even if said laser can’t penetrate the exterior mould line it should have no problem providing a near complete full spherical firing solution. There may be some gaps from the tails and wings and so on but since they are so small they can easily be compensated for by minor movement of the aircraft’s attitude. Since targeting and flying is controlled by a computer such minor adjustments could be carried out automatically without need for the pilot to get involved.

Trust me, I would much rather be on that design team than what I am currently doing these days. Yet jamming a turret into a rather small space there seems quite a challenge even without the laser technology that still needs to be developed. It is my understanding that venting excess heat is currently a major obstacle in the development of such a fighter based laser as well. Perhaps it can be done with the F-35, but I think a fighter designed with the role in mind would be the best solution.

You’re just reading from a catalogue. Why bother with TVC when you don’t need that sort of agility for lethality or survivability purposes. TVC isn’t going to make your aircraft a better ground attack platform.

But your also getting increased fuel efficiency out of the deal. You can argue that sort of agility isn't needed, but there are unintended scenarios a F-35 could end up in, where it could be helpful.

And who said the F-35 has a turning circle of a SR-71 or C-17? Why waste everyone’s time with such factless bile. Besides I’ve been a C-17 that turned pretty damned tightly…

I didn't say the F-35 has a turning circle of the SR-71 or C-17. If it does have the agility of a clean F-16 that isn't a problem, but there is always room for improvement. What I am trying to get across is that even if in the future we have laser systems that can cut through ground targets and attacking fighters or missiles, a flying truck solution isn't ideal.

A new missile is being fielded. Further this kind of argument doesn’t take into account a range of other issues. For example how is the engagement geometry going to get within the AIM-120D’s HOBS envelope so an AIM-9X is needed? The F-35 doesn’t need to manoeuvre to engage then it will stay high energy. So how is someone going to get through its AIM-120D engagement envelope and up close so an AIM-9X is needed? Teleportation?

JDRADM right? That is years down the road and I am rather unoptimistic that a single missile could effectively fill the roles and improve upon the AIM-120D, AIM-9X, and AGM-88E. Either way I don't believe we should count on that solution. Supposedly the AIM-9X could be used in such a lock-on-after-launch mode, and once we have a configuration that allows for more than four missiles to be carried internally, I think it's integration should be a priority. Yes ideally an enemy fighter would never catch the F-35 by surprise or make it past the AIM-120s, but not everything works as planned. The AIM-120 isn't nearly as maneuverable as the AIM-9X anyway. Yet I suppose this is simply a matter of personal opinion.

 

[red admiral]

Much is made of the ground erosion "problems" that PCB brings yet without real facts to make the point. If you sit on tarmac with max PCB for a few minutes, its definitely going to have a detrimental effect. However, the same problem also occurs with the Harrier. A study I saw recently detailed the ground erosion from the Pegasus on a variety of a different surfaces. It wasn't a significant problem for any, but the ones of most concern were tarmac (beginning to melt at 200°c) and carrier decks (burning anti-skid paint). The typical Harrier VL and engine stop doesn't take that long so the temperatures don't rise that much. Going to a low approach speed (around 50knts) and the problem completely disappears.

Hot gas ingestion could be more of a problem, but it depends heavily on detailed configuration. Really, you can't get much better than the P.1216 three poster arrangement. There were some rather nice follow on designs to the P.1216 with greater stealth incorporated into the design making it a fair bit chunkier.

The main performance differences between JSF and Harrier are supersonic speed and greater range. The simply fact is that Harrier is old and a new build aircraft is needed as a replacement. The X-35 lift fan arrangement has advantages but involves risk in development. The program stills suffers technical problems and cost is seriously blooming, especially for the B version. Realistically I can see JSF costing more than F-22 by the time it gets into service.

 

[sferrin]

Realistically I can see JSF costing more than F-22 by the time it gets into service.

Didn't the "cheaper" Virginias end up costing more than the Seawolfs? I'd be curious how much cheaper JASSM is than finishing TSSAM would have been too.

 

[Abraham Gubler]

A study I saw recently detailed the ground erosion from the Pegasus on a variety of a different surfaces. It wasn't a significant problem for any, but the ones of most concern were tarmac (beginning to melt at 200°c) and carrier decks (burning anti-skid paint.

And any such proper benchmark analysis would have to compare the additional deck maintenance caused by downwards thrust to the maintenance required to keep arrestor gear and steam catapults operational… Even if you had to resurface after every carrier cycle you wouldn’t even be in the ballpark of cost and labour demands to keep four wires and two catapults running…

The program stills suffers technical problems and cost is seriously blooming, especially for the B version. Realistically I can see JSF costing more than F-22 by the time it gets into service.

Not quite. Production costs are actually been pushed down every year. With ~5% savings over predicted cost this year and last year. The predictions of additional cost to the developmental program are based on benchmarking delays in F-35 development with that of fourth generation aircraft delays (F-14, etc). There is no serious benchmarking being made on actual technical issues. Just comparative schedules which don’t take into account the huge differences in development engineering brought about by the past 30-40 years of technology progress (ever heard of the computer?).

If the F-35 doesn’t require any significant changes to its production standard (unlike the F-22) then because of the scale of the program (more than an entire F-22 production per annum) it will return strong savings. If there is one thing modern defence aerospace can do it is drive down cost of established aircraft production lines. You can benchmark every production program from F-14 to F-22 (except F-16 but let’s just forget that first wing that didn’t work) to see how such savings emerge.

 

[Abraham Gubler]

The AIM-120 isn't nearly as maneuverable as the AIM-9X anyway. Yet I suppose this is simply a matter of personal opinion.

I think we basically agree so to avoid further hijacking of 'AV-8B vs F-35B' into '5th Generation Air Combat' will avoid making further responses.

 

[SOC]

The AIM-120 isn't nearly as maneuverable as the AIM-9X anyway. Yet I suppose this is simply a matter of personal opinion.

I think we basically agree so to avoid further hijacking of 'AV-8B vs F-35B' into '5th Generation Air Combat' will avoid making further responses.

Yeah, seriously. The last time I tried to use the "split thread" thing to excise off-topicness to a new thread, I sort of deleted everything. ;D

 

[sferrin]

The AIM-120 isn't nearly as maneuverable as the AIM-9X anyway. Yet I suppose this is simply a matter of personal opinion.

I think we basically agree so to avoid further hijacking of 'AV-8B vs F-35B' into '5th Generation Air Combat' will avoid making further responses.

Yeah, seriously. The last time I tried to use the "split thread" thing to excise off-topicness to a new thread, I sort of deleted everything. ;D

You say that like it's a bad thing.

 

[Simon666]

So I guess we’re all lucky you aren’t on the design engineering team for such a solution? Even if said laser can’t penetrate the exterior mould line it should have no problem providing a near complete full spherical firing solution. There may be some gaps from the tails and wings and so on but since they are so small they can easily be compensated for by minor movement of the aircraft’s attitude. Since targeting and flying is controlled by a computer such minor adjustments could be carried out automatically without need for the pilot to get involved.

The problem seems fundamental in aerodynamics. A lense with such coverage would need to be spherical, and flow separation is pretty much unavoidable on some parts. At such Reynolds numbers, a sphere of the size needed will always have some flow separation, which will be problematic if you want a good quality laser beam through the separated airflow. People are studying solutions, but all they'll find is probably improvements. Not that incomplete spherical coverage would be a showstopper, I'm just saying it's not likely.

 

[mz]

Umm, how about a window?

 

[red admiral]

Not quite. Production costs are actually been pushed down every year. With ~5% savings over predicted cost this year and last year.

It just depends on what you include as "cost". The maintenance and other life costs are currently going through the roof, especially for the B version. Once you're a couple of billion dollars over budget, it starts to add up to real money. We'll have to see what happens to the costs when LRIP V starts in the middle of next decade. The news from what I hear this side of the pond isn't too great.

 

[GTX]

Production costs are actually been pushed down every year. With ~5% savings over predicted cost this year and last year.

Very true - speaking as a supplier to the F-35, I can assure you that the pressure to meet/exceed (i.e be less expensive) price targets is extreme! In fact earlier this year, I witnessed a number of other companies loose contracts for parts they were already producing for the earlier LRIPs because someone else was a "few dollars" cheaper! In fact the pressure is so great that some companies are deciding to not even pursue the work.

The maintenance and other life costs are currently going through the roof,

Based upon what - theses aspects have hardly even been touched on yet. Moreover with so few aircraft actually flying, there is no real representative data to base such comments on.

We'll have to see what happens to the costs when LRIP V starts in the middle of next decade

Err, LRIP 5 is due for production contracts in about 2010/2011 with aircraft roll-out in about 2012/2013.

Regards,

Greg

 

[Stargazer]

Experience proves that going for the "few dollars cheaper solution" is seldom advisable. Yet despite the many decades of experience accumulated, politicians and military decision-makers choose to follow that route and therefore seriously undermine, cheap choice after cheap choice, the quality of the finished product.

 

[GTX]

Experience proves that going for the "few dollars cheaper solution" is seldom advisable. Yet despite the many decades of experience accumulated, politicians and military decision-makers choose to follow that route and therefore seriously undermine, cheap choice after cheap choice, the quality of the finished product.

In this case, the decision is being made by the companies such as Lockheed Martin.

Regards,

Greg

 

[sferrin]

Experience proves that going for the "few dollars cheaper solution" is seldom advisable. Yet despite the many decades of experience accumulated, politicians and military decision-makers choose to follow that route and therefore seriously undermine, cheap choice after cheap choice, the quality of the finished product.

In this case, the decision is being made by the companies such as Lockheed Martin.

Regards,

Greg

I think he may have been referring to the governments habit of cancelling things to get something else cheaper only to find the "something else" costs just as much or more. They always seem to forget those pesky R&D dollars. What would the incremental Seawolf costs have been compared to the need to R&D the Virginia's in addition to their purchase? How much to iron the bugs out of AGM-137 (TSSAM) vs the need to R&D JASSM and work out it's bugs? How about the on again off again DD-21/ DD/X / DDX / Zumwalt whatever you want to call it this week? How much did they add to the final costs by all the indecision (never mind that now they've cut it down to three units which will undoubtably cause many to trumpet "it was a poster child for exploding costs due to poor USN and contractor performance", never mind it was political meddling that jammed it up)? Look what happened to Burke costs because of interrupted pipelines. They never effin' learn.

As for LM pressure on the subs it is definitely dog-eat-dog and if you have a hiccup god help you because there will be 20 other companies waiting to take the work from you.

 

[elmayerle]

Actually, the problem wasn't so much that the TSSAM had bugs but that Northrop hadn't managed to control costs well enough and the unit cost rose to what the USAF & USN considered an undesireable level (granted, it didn't help that teh US Amry bailed on them roughly a year or so earlier - pity that as we got the "stop work" just before a test flight to verify a whole bunch of fixes to problems that'd come to light on previous tests of that variant). Between management problems there and some of the delays on the B-2, I can understand why, on the ATF, the USAF was less than enamored with Northrop's management, despite their demonstrated technical superiority. And yes, I know whereof I speak as it was the cancellation of TSSAM that got me laid off from Northrop.

Really, it was a shame it was cancelled as some of the proposed follow-on derivatives moved into the UAV area.

 

[sferrin]

Actually, the problem wasn't so much that the TSSAM had bugs but that Northrop hadn't managed to control costs well enough and the unit cost rose to what the USAF & USN considered an undesireable level (granted, it didn't help that teh US Amry bailed on them roughly a year or so earlier - pity that as we got the "stop work" just before a test flight to verify a whole bunch of fixes to problems that'd come to light on previous tests of that variant). Between management problems there and some of the delays on the B-2, I can understand why, on the ATF, the USAF was less than enamored with Northrop's management, despite their demonstrated technical superiority. And yes, I know whereof I speak as it was the cancellation of TSSAM that got me laid off from Northrop.

Really, it was a shame it was cancelled as some of the proposed follow-on derivatives moved into the UAV area.

Aren't you the guy who mentioned the picture of TSSAM flying through the bunker door when LM was showing off the JASSM doing that?

 

[red admiral]

Based upon what - theses aspects have hardly even been touched on yet. Moreover with so few aircraft actually flying, there is no real representative data to base such comments on.

I work on the UK side of things, and through life costs are definitely being looked at. The support contracts haven't been signed yet of course, but people have a fairly good idea of costs. Realistically the UK has already sunk so much money into JSF-B that it's going ahead no matter of cost.

Err, LRIP 5 is due for production contracts in about 2010/2011 with aircraft roll-out in about 2012/2013.

I might be mixed up with which batch but I've seen so many different schedules it's difficult to remember what the current one is. I saw one schedule from only a few years back which planned IOC in 2008.

 

[blackkite]

A series of questions that I have been looking to answer for a while:
2) Has the Harrier/Pegasus concept reached the end of its development potential? What happened with the PCB burning trials? Why couldn't the afterburners be applied to the rear jets only?

According to 'PEGASUS THE HEART OF THE HARRIER';
"To get balanced thrust, BS100 had a bypass ratio of about 1:1 where Pegasus's bypass ratio is 1.4:1."
It means BS100 cold flow was smaller and hot flow larger compared with Pegasus for afterburnig in the cold flow(PCB) when VTO.
The use of the front nozzles allowed the use of air at about only one-third of the temperature of the rear nozzles, and thus a greater boost was available.
PCB's outlet temperature is lower than the afterburner's outlet temperature applied to the hot gas.
PCB has good characteristic for runway erosion.
But BS100's hot gas recirculation problem was more severe than Pegasus as already mentioned.
I also imagine that PCB's hot gas has bad influence for after structure and forced to use heavy heat resistant materials instead of light aluminium alloy.
I wonder about acoustic vibration, that is also problem for pilot and after structure, too.

 

[GTX]

Based upon what - theses aspects have hardly even been touched on yet. Moreover with so few aircraft actually flying, there is no real representative data to base such comments on.

I work on the UK side of things, and through life costs are definitely being looked at. The support contracts haven't been signed yet of course, but people have a fairly good idea of costs.

True the through life costs are definitely being looked at but any figures are only very rough. I base this one two main points:

1. LM still hasn't (at least as of the end June) finalised their sustainment concepts (the basis for maintaining the platform). Whilst some system suppliers might have, the overall picture, let alone the individual users plans are far from ready.
2. Most importantly (and as I alluded above), with so few aircraft actually flying, there is no real representative data to base any assessments of operating cost on. Sure, a lot of modelling has been done and there are targets to meet, but until there is more real world hard data, no-one will know.

And before anyone tries to jump on this and say "aha, it will be more expensive", just remember that it could very well go the other way. For instance, to use the engine as an example, both P&W and the FET have predictions on the life of the F-135 and F-136 respectively (i.e., it will need this sort of maintenance in this period etc,). However in real life, the engines will be have a more condition based regime. Given the advances in technology (often based on commercial practices - and impressive I can tell you), I fully expect there will be far reduced need for major maintenance during the life of the platforms. As such, the support/operating costs for the engine and thus overall platform will be far lower than previous platforms.

Regards,

Greg

 

[elmayerle]

From personal experience, I will say that one thing in the F-35's favor is that the usual NIH (Not Invented Here) attitude has been reversed and they'll look at good ideas from anywhere, and not just within aerospace. I think this is going to make for some major differences. And I know they're constantly looking at ways of doing problem-prone areas better to reduce the problems. If the truth be known, the aricraft would be lots worse if it had been done strcitly by LM-Aero as both NGC and BAE, as the two major subcontractors, have contributed definitely original technologies that have improved the design as have several of the other subcontractors.

 

[blackkite]

What happened with the PCB burning trials?

Hi!
http://www.flightglobal.com/pdfarchive/view/1980/1980%20-%201853.html