F-35 Cancelled, then what ?

[Courtney Mil]

Indeed. Fully aware of most of that, Engines. It's still such a shame that the canopy sill starts ramping up from the throttle and that there is no view out the back.

[ColdCollation]

'No view out the back'?

Pilots of the previous Lightning would positively covet the view from the newbie, surely? :}

[melmothtw]

Interesting explanation Engines. I'm curious though as to why the canopy arch was needed, when the F-16 (also used in a bird-strike-rich environment) doesn't require this vision-limiting feature.

[ColdCollation]

The F-16 has a rather sturdy HUD designed to cope with bird strikes, which the F-35 hasn't.

[melmothtw]

Cheers Cold

[ColdCollation]

Nee worries. :)

[Engines]

Guys,

Thought I'd reply.

Courtney, I've sat in the cockpit a few times. i'm not a pilot, but there is a view out of the back. Is it as good as a Typhoon? No. Is it better than a Tornado? Yes. But there is a view. The canopy sill slope upwards from the throttle starts from a very low position, and to my (untutored) eye, the view wasn't significantly compromised. But I'll defer to your far more relevant views.

As I inferred in my last post, there are designers who think that the push for ultimate cockpit field of view went too far in the 80s and 90s. There are certainly aircraft that took a significant 'hit' in terms of performance. As ever, pilots and results will decide. (Sea Harrier had a fairly limited view, but that didn't stop it doing fairly well, as I remember).

Bird strike. The figures are lost in my ever more addled memory, but I do know that the requirement for F-35 was far more severe than that levied on the F-16. (or the F-15). This drove the need for a thicker and tougher forward section. (UK had a key hand in this requirement). The canopy arch is, as I remember, is there to help handle the transition between the reinforced forward section and the thinner aft. (And people might like to know that Typhoon struggled to achieve its own bird strike resistance requirement).

Location of that arch was modelled and adjusted over a period to get all the pilot views included. The F-35C requirement has given it a very good 'over the nose' FOV. As ever, it's a compromise, like most real things in the world.

Best regards as ever to those trying to do the right thing (for everyone)

Engines

[Onceapilot]

Tornado has mirrors :ok:

OAP

[melmothtw]

The F-35's helmet/sensors means that when the pilot looks behind him, he sees behind him. No?

[ColdCollation]

F-16 is also the only in-service jet with an 'unbroken' bubble, no? Not knocking anyone but it's perhaps therefore an unfair comparison (or, if you prefer, the pinnacle/zenith of something or other...).

[melmothtw]

Yes Cold, I guess my question about the canopy rail was really meant for all types designed after the F-16. If they were able to attain pretty much perfection in terms of pilot visibility in 1974 with no obvious increase in the danger of bird-strike etc (surely there would have been a redesign in the last 40 years if there was an increased danger), then why has every aircraft (excluding the F-35, the reason for which you have given) retained the visibility-limiting rail?

[ColdCollation]

melmothtw, I really wasn't having a dig.

F-16 brought with it a lot of new thinking - a reclined (30-degree) seat to help g-tolerance, a side-stick controller, and that one-piece canopy (for which the HUD, as mentioned, took the pain).

It's not just the canopy which hasn't been emulated. The Israelis, for example, when designing the abortive Lavi, were already flying -16s but decided against a side-stick as they felt it was a liability if the pilot got injured.

But how do you give a pilot a superlative view? Why, you give him a magic helmet... :ok:

[melmothtw]

Didn't think you were Cold. The F-16 canopy thing is just something that has perplexed me for a while. It appears to be the pinnacle of design, yet no other manufacturer has tried to emulate it in over 40 years (even the Lavi you mention opted for the rail).

[LowObservable]

The F-22 has an unbroken bubble - quite heavy, I believe - but a moderate birdstrike requirement because it's not supposed to spend a lot of time where birds live. Two-piece lids are considered anathema from the stealth viewpoint, although (so far) the T-50 has one.

Also because it's not designed for low altitude operations, the F-22 can afford to jettison the canopy before ejection. The F-35 has to provide for through-the-canopy ejection using explosive cord and breakers on the seat - another reason for that is the forward hinge, I believe, which militates against jettison, but was adopted to some extent so that the hinge would be common across three versions.

In other news:

"We're being very cautious right now in what we're allowing the operational users to do with the airplane, because we haven't quite gotten to why it happened yet," the general said. (http://www.azcentral.com/story/news/local/glendale/2014/08/07/luke-path-becoming-main-f-training-site/13708449/)

Remember when this engine issue was isolated and it was all going to blow over in a few days?

[Willard Whyte]

I'm dying to 'hear' some of our 'their airships', and admirals, use the word gotten.

[Lyneham Lad]

Tornado has mirrors :ok: OAP

Presumably wing mirrors...

I know, I know,
Hat, coat, door...

[Engines]

LO and others,

It's interesting how much attention a potentially simple thing like a cockpit view can get. A couple of points, they may help.

The F-35 ruled out canopy jettison more or less straight from the start, mainly due to the need for rapid zero-zero ejection for the STOVL aircraft. The forward hinge design was chosen to help with signature, and also overall weight, as well as providing the best access. Many, many CAD studies and mock ups went into selecting that layout. The fan door aft of the cockpit also ruled out an aft hinge.

No breakers on the Martin Baker seat, as far as I remember. Just exit through the remains of the canopy once blown by the MDC.

As I said, the big difference between F-35 and most other US jets was the severity of the bird strike resistance requirement, which was stiffer than for any legacy US jets, and was pushed very hard by the UK in particular. That led to the need for a reinforced forward section, and the arch, to prevent deformation of the transparency under impact. I believe (can't be sure, but a decent guess) that a similar design process led to the Typhoon design.

Lockheed had all the info, intellectual rights and experience on the F-16 canopy design right there in Fort Worth. They'd have used it if it met the requirements of the F-35 programme. It didn't, so they couldn't.

Oh, and the first fighter jet with a reclined seat (as far as I am aware) was the Lightning.

Best Regards as ever to those making the calls

Engines

[Davef68]

The UK Harrier II had a much tougher/thicker windscreen than it's US cousins for the same reasons - they were expected to spend a lot more time in an environment where avian hazards exist.

The F-16 was designed as a pure air-to-air dogfighter, and not to spend a lot of time down amongst the weeds.

[melmothtw]

The F-16 was designed as a pure air-to-air dogfighter, and not to spend a lot
of time down amongst the weeds.


Yes, accept that Dave, but in 40 years of operations it has dropped more bombs at low level than most other types in service today. If there was a problem with the canopy design for this role, in that time there would have been a redesign...and there hasn't been.

Anyhow, I think I've had my canopy curiosity sated for now.

Thanks to all....

[Courtney Mil]

The reason for the 30 degree tilt in the F-16 was to make the seat fit into the fuselage. LM pushed the so called g tollerence benefits, which are, at best, very slight. In truth there are some drawbacks, most notably the tendency of the pilot to tilt his head forward, very straining under g. Remember that most seats are inclined about 15 degrees anyway. F-16 gains more by raising the pilots feet.

As for cockpit visibility, this is a marked step backwards from, say, F-15. And, by the way, that has mirrors too.

[dat581]

Can't be as bad as your Phantom though?! :E

[Courtney Mil]

No, that wasn't so good, Dat. ;)

[Bevo]

Of course the Phantom had special sensors (another pair of eyes) to help with the visibility. ;)

[Courtney Mil]

In some cases they were very high resolution sensors too! Oh, and the best radar of its day.

But none of this excuses the appalling rearward vis from the F-35. I know, it's all to do with the lift fan. Let's hope STORVL is worth it. With all the other compromises it could seem like a compromise too far. Too late for all that now, just get the engine fixed.

[lightningmate]

The Canberra B(I)8 had the best Pilot's external visibility capability by far across the relevant types I have flown. PR9 was probably very similar.

lm

[Vendee]

Yes, accept that Dave, but in 40 years of operations it has dropped more bombs at low level than most other types in service today.Except that its only been operational for 34 years ;)

[Courtney Mil]

True, but that just makes the point that Mel made even more impressive.

[kbrockman]

True, but that just makes the point that Mel made even more impressive.
... And once more underwrites the theory that it is fairly straightforward making a good air support/bomber out of a good air dominance fighter (like the MIII, M2000, F14, F15, F18, etc... ) but much harder to do it succesfully the other way around (F111, Tornado, F4 even some might say).

[Rhino power]

...F4 even some might say

Really? Who? The F-4 wasn't designed as a bomber which was then turned into a fighter, not by any stretch of the imagination!

-RP

[GreenKnight121]

Actually - The design of what was eventually to emerge as the McDonnell F-4 Phantom began in August of 1953. The McDonnell design team was headed by Herman Barkley. Initially, the goal of the team was to extend the production life of the F3H Demon single-seat carrier-based fighter by boosting its performance and improving its versatility. Tis series of in-house designs were also known as the Model 98 series by the company) .....
On September 19, 1953, McDonnell submitted its Model 98B project to the Navy's Bureau of Aeronautics (BuAer) in the form of an unsolicited proposal.
.....

Although the Navy was favorably impressed by the Model 98B proposal, the Grumman XF9F-9 Tiger and the Vought XF8U-1 Crusader which had been ordered respectively in April and June of 1953 appeared to satisfy all the Navy's immediate requirements for supersonic fighters. Nevertheless, the Navy encouraged McDonnell to rework its design into a single-seat, twin-engined all-weather attack aircraft to compete against designs being worked on by Grumman and North American.



McDonnell submitted a formal development proposal for the F3H-G/H to the Navy in August of 1954. The Navy responded in October of 1954 by issuing a letter of intent for two prototypes and a static test aircraft. The Navy assigned the designation AH-1 to the project, reflecting its intended ground attack mission. The AH-1 was to have no less then eleven weapons pylons. Armament was to consist of four 20-mm cannon.



On December 14, 1954, the multirole mission of the aircraft was formally abandoned by the Navy, and McDonnell was requested to rework the proposal as an all-weather interceptor. McDonnell was instructed to remove the cannon and all hardpoints except for a centerline pylon for a 600-US gallon fuel tank. In addition, troughs were to be added for four Raytheon Sparrow semi-active radar homing air-to-air missiles. A Raytheon-designed APQ-50 radar was added, this installation being essentially that installed in the F3H-2 Demon. A second seat was added to accommodate a radar operator.


Yes - the first USN interest in, and specification for, what eventually became the F-4 Phantom II was as a competitor to the Grumman A2F (A-6) Intruder and A3J (A-5) Vigilante!


FGH-3 mockup:
http://i22.photobucket.com/albums/b336/Bager1968/Aircraft/attack-strike%20aircraft/F3H-Gmockup_zps729cb273.jpg

http://i22.photobucket.com/albums/b336/Bager1968/Aircraft/attack-strike%20aircraft/F3H-Glowfrontalsm_zpsc3a0c6af.jpg

http://i22.photobucket.com/albums/b336/Bager1968/Aircraft/attack-strike%20aircraft/CopyofF3H-GHBrickmansm_zps36c464fb.jpg

[Rhino power]

GK121, semantics... ;) I stand by my comment, the 'F-4 wasn't designed as a bomber...'

-RP :ok:

[LowObservable]

It's interesting, however, that the fighter that set standards for a generation emerged from such a screwed-up development process - single-seat fighter to single-seat bomber, back to two-seat all-missile interceptor with a big radar, and then to air-superiority with slats, a smaller radar and a gun. And then the last big mod program was the Israeli Kurnass 2000, which was (drum roll) a dedicated precision strike aircraft.

Of course, if you look at the history of the 737...

[Rhino power]

LO, not forgetting the Japanese 'Kai', the German 'KWS/ICE', the Hellenic 'PI2000/AUP' and the Turkish '2020 Terminator' and 'ETM' mods, which were all significant in themselves... :)

-RP

[LowObservable]

There were a few new-gen fighter radars, that's true... K2000 was pretty huge, though, with Popeye integration and a purpose-developed radar.

[Rhino power]

And the Kurnass 2000 could've been an even more significant upgrade, if the PW1120's had been included!

-RP

[LowObservable]

Of all sad words of tongue and pen, the saddest are these, "It might have been". The PW1120 Kurnass would have been a beast. Plus, even today, most fighter radars can't do GMTI and SAR interleaved, which was the Ku-band APG-76's party trick. Not to mention Popeye...

[Courtney Mil]

Kbrock,

Apart from anything else, I do agree about fighter to bomber, bomber to fighter. F-15 is probably a better example.

[kbrockman]

Really? Who? The F-4 wasn't designed as a bomber which was then turned into a fighter, not by any stretch of the imagination!

-RP

That's why I said "even some might say", the F4 was at best a compromised fighter in its beginnings, the all-round aspect as initially envisioned by the NAVY/MARINES, certainly created its own set of unique problems down the line of its operational life when used as an air dominance fighter (WVR+dogfight distances).

Courtney, I agree with the F15 (and all the others I quoted).

[Rhino power]

LO, Turkey have the Popeye integrated on their 2020's but, I digress, this thread is about the F-35. Apologies to all for the break in coverage! :O

-RP

[GreenKnight121]

Actually, all this F-4 discussion is very pertinent to the F-35! ;)

Remember this?

Is the F-35 Joint Strike Fighter the New F-4?
How the controversial Joint Strike Fighter resembles the classic Cold War jet
https://medium.com/war-is-boring/is-the-f-35-joint-strike-fighter-the-new-f-4-75aee4a354bc

:E

I always thought comparing the F-35 to the F-4 was a complement - mainstay of a dozen nations' air power for decades, an extremely successful aircraft from carriers as well as land bases, rugged and dependable, easily upgradable through several decades, world-beating for its era, and listed by almost everyone as an all-time classic!

[Rhino power]

...mainstay of a dozen nations' air power for decades, an extremely successful aircraft from carriers as well as land bases, rugged and dependable, easily upgradable through several decades, world-beating for its era, and listed by almost everyone as an all-time classic!

Somehow, I don't ever see those plaudits being applied to the F-35. In fact i'd say they were mutually exclusive! ;)

-RP

[Minnie Burner]

Screwfix have the answer: Two of these per Typhoon?


http://s7g3.scene7.com/is/image/ae235?$p$&layer=0&size=281,281&layer=1&size=281,281&src=ae235/77224_P

[PhilipG]

To ask a stupid question, are any non test vehicle F35s flying without time restrictions at the moment?

[Courtney Mil]

A funny thing, PhilipG, the F-35 fanatics are a little quiet at the moment. Equally good is the (so called) "antis" aren't trying to score points whilst the program is down. It's a pretty serious set back that's going to take a very long time to fix properly.

It's a time to wait and see. And take any early announcements with a huge pile of salt - so much money involved, there will be a lot of promises and lots of postings about how well the rest of the program's going.

Wait and see.

[Rhino power]

so much money involved

And, I suspect, much more yet... :(

-RP

[GreenKnight121]

Well, I'm a supporter of the F-35 - but I also opposed dropping the RR/GE F136 "second" engine - just because of these kind of issues!

[Whitewhale83]

Also makes the 'you dont need a twin engined aircraft anymore because modern engineering is so advanced!' argument a little awkward.

[melmothtw]

Also makes the 'you dont need a twin engined aircraft anymore because modern engineering is so advanced!' argument a little awkward.

It's a slightly different issue in this case. An F-35 powered by two F135 engines would just have double the potential for an engine failure, so paradoxically a single-engined F-35 actually is actually less likely to go tech right now...

[LowObservable]

Equally good is the (so called) "antis" aren't trying to score points whilst the program is down.

Never interrupt your enemy when he is making a mistake. - Napoleon (attrib.)

[Courtney Mil]

Good call, LO.

[MSOCS]

Never interrupt your enemy when he is making a mistake. - Napoleon (attrib.)

By your own standards LO, surely you shouldn't have said anything in almost 10 years in that case?

If only...

GK121 - absolutely spot on there. No arguments from me on that. Pratt has a history of making reliable engines...oh hang on..

[sandiego89]

Quote:
Also makes the 'you dont need a twin engined aircraft anymore because modern engineering is so advanced!' argument a little awkward. It's a slightly different issue in this case. An F-35 powered by two F135 engines would just have double the potential for an engine failure, so paradoxically a single-engined F-35 actually is actually less likely to go tech right now...

And if you have a blade rubbing incident, that results in blade separation, fire and parts departing the engine as it looks like the F-35A at Eglin did, the second engine may not save your bacon... as the saying goes, the second engine has enough power to get you to the scene of the crash....

[John Farley]

Also makes the 'you dont need a twin engined aircraft anymore because modern engineering is so advanced!' argument a little awkward.

In my view it is not a 'liitle awkward' but plain wrong. The reason why the F35 should be a single engine design is down to engineering facts not "modern engineering is so advanced".

The engineering facts are that if you can fit a single engine that has enough thrust to meet the spec the aircraft will be safer (in respect of engine failure) than a twin design of the same total thrust.

It was appreciating this in the 70s that made the USN change from "our new trainer must have two engines" to "single engine designs are acceptable" and was one of the reasons why the single engine Hawk became the starting point for the T45 Goshawk.

BTW the first Alpha Jet, Tornado and Typhoon total losses all involved double engine failures.

Of course if you need two engines to get the total thrust that you need for the design you have no option but to put up with the various disadvantges that brings.

[LowObservable]

The fact is that you will have half as many engine failures with a single, other things being equal.

But they are not necessary equal. Engines don't scale geometrically and larger engines are more complex (more blades, for instance). Components such as disks may be more heavily loaded and damage to the airframe more severe. (QF32.)

That's also part of the reason that large engines may have a lower thrust/weight ratio than smaller engines (compare the F414/EJ200 with an F110, not to mention F135). Two engines are shorter (nice fit for a delta) and when you get to a single large engine, arranging all the systems around a hole the size of an L.A. storm drain is no fun at all.

And while some single-engine failures on a twin may be catastrophic (it sounds as though the most recent F135 failure was bad enough to do that), the great majority of power-loss events on a single-engine fighter will result in loss of aircraft.

[glad rag]

Screwfix have the answer: Two of these per Typhoon?


http://s7g3.scene7.com/is/image/ae235?$p$&layer=0&size=281,281&layer=1&size=281,281&src=ae235/77224_P


Nope, just can't get this one..:confused:

[glad rag]

BTW the first Alpha Jet, Tornado and Typhoon total losses all involved double engine failures.





References please.

Wasn't the FIRST Tornado loss @ Manching where the aircraft looped too low?

Ref ASN Aircraft accident 16-APR-1980 Panavia Tornado MRCA 98+05 (http://aviation-safety.net/wikibase/wiki.php?id=55704)

I remember this because, as part of the transfer from 1940's tech to 1970's tech, the RAF ground school, as part of their flight safety induction for us played the CVR of the crew after they realised it was endex, all the way down. A shocking thing for young Erks to listen to, very upsetting if I'm honest, BUT it rammed the flight safety message home and molded the techs attitudes.

http://www.tornado-data.com/History/Prototypes/P04.jpg

[kbrockman]

The irony off course is that the F35B (MARINES) is factually a 2-engined (2 propulsion sources) equipped fighter in the most crucial phase of its flight (TO and LANDING both rolling and vertical), ironic even more that it is an added liability iso an extra safety because any failure of one of both power-sources (which are mechanically coupled= extra risk) leads to an immediate catastrophic failure.

The YAK-41 suffered from this shortfall too btw.

Also the notion that 2 engines or more don't provide an extra safety measure is just plain and simple wrong (and I cannot understand why anybody would say differently).
the US DoD, at the end of the millennium, did a widespread statistical study on engine related class-A mishaps and did indeed show a significant elevated risk for single engined aircraft, the F16 being the best performer for single engined fighters was still far behind one of the weaker performing twins like the F14.

That being said, I do think that , under most circumstances, nowadays a single engined fighter, trainer or other single or twin-seater , is a very viable option because of improved technological fidelity.


EDIT,

found a younger chart from 2014 (not as detailed as study mentioned before)
http://www.afsec.af.mil/shared/media/document/AFD-140729-015.pdf


Also both the ISRAELI air force ,and before the USAF (during VIETNAM), found a strong correlation between risk for single engined fighters performing ground support tasks (close air support) and multi engined fighters.
The F104 was very susceptible to ground fire , the F5 and F4 much less so (props are also better btw).
Pierre Sprey's remark concerning the survivability of the F35 against light ground weapons was actually valid.

[John Farley]

Sorry chaps

I should have said the first total losses due to technical failure.

I wouldn’t count poor Ludwig’s accident as a specific Tornado one.

As for open source references I don’t have any to hand but I believe they would not be hard to find. The Alpha Jet was in Egypt and the Typhoon of course in Spain.

More importantly, while I am no expert in all the reasons I have heard some very bright people talking about them and they revolve not just on the obvious two engines to fail but on the much more complicated installations involved with a twin when you have to be able to fly the aircraft on either engine (I believe the gearbox that links both engines on a Tornado for example absorbs some 300+ HP) plus the close proximity of the engines to each other where the bad donk can so easily damage the good one. (quite unlike the civvy twin case) .Since a lot of engine failures result from intake conditions a common intake for both engines can obviously lose you both (Spanish Typhoon).

Like I said there are lots of factors and I am sure I have not listed them all here.

In the case of the Harrier single engine installation we decided that the original very complex hydro-mechanical engine fuel control system was the single most likely cause of engine failure so a standby independent manual fuel system was incorporated (in the days before electronics and redundancy was available in that department).

The design of high performance military aircraft is not a simple matter with many compromises involved. The teams involved are not thick either. So those who pick simple holes in whatever issue is being discussed probably say more about themselves than the topic

[glad rag]

I wouldn’t count poor Ludwig’s accident as a specific Tornado one.

There were a number of modifications to the static pressure[s] sensing system[s] that were embodied as a result however...

:ok:

[Vendee]

I believe the gearbox that links both engines on a Tornado for example absorbs some 300+ HPEach engine has its own gearbox c/w genny, fuel pump and hyd pump (r/h gearbox also has apu). The gearboxes are linked through a crossdrive clutch which from memory is normally open and closes either manually or when set to auto...with certain RPM differential (can't remember how much).

[kbrockman]

The design of high performance military aircraft is not a simple matter with many compromises involved. The teams involved are not thick either. So those who pick simple holes in whatever issue is being discussed probably say more about themselves than the topic

That's nothing more than a cheap ad hominem attack.
It would be equally daft as saying that people with (blind) faith in heavily politicised projects like the F35 are naive and lack a healthy amount of critical thinking.

Let's not go that way.

[Turbine D]

John,
As for open source references I don’t have any to hand but I believe they would not be hard to find. The Alpha Jet was in Egypt and the Typhoon of course in Spain.

Here is some data from the USAF based on their experience where you can compare both the F-16 (single engine) and F-15 (twin engine) as to engine mishaps. The data, as I recall, does not include bird strikes or support system failures but actual engine caused failures. I think you will see an advantage to having two engines besides the propulsion power two provide verses one. Be sure to check out the data charts below the notes that are very interesting.

http://www.afsec.af.mil/organizations/aviation/enginestatistics/
The design of high performance military aircraft is not a simple matter with many compromises involved. The teams involved are not thick either.
There are compromises and then there are compromises. The F-35 is a compromise gone too far resulting in a sub-performing aircraft across the board, IMHO.

TD

[Turbine D]

Original quote by John Farley:
In my view it is not a 'liitle awkward' but plain wrong. The reason why the F35 should be a single engine design is down to engineering facts not "modern engineering is so advanced".

The engineering facts are that if you can fit a single engine that has enough thrust to meet the spec the aircraft will be safer (in respect of engine failure) than a twin design of the same total thrust.
I respectfully disagree with your statements here.

The F-35 premise going in that one could design a three service aircraft where only one service required VTOL or STOL using the same airframe was erroneous. The result of this was an aircraft design that required one engine because of the lift fan placement location. In fact, this lift fan feature caused the fuselage to become "fatter" to preserve the ability to carry armaments internally to preserve stealth characteristics that actually became compromised because of the resulting fuselage design. Also, the area rule became compromised, adding to drag and resulting in the F-35 being underpowered and lacking in speed. It will probably require two engine upgrades to increase thrust level overcoming the drag penalty.

Had the airframe been designed around only Air Force and Navy requirements, you would have seen a two engine aircraft, pencil like fuselage, plenty of speed and un-compromised stealth characteristics, but smaller and more agile than the F-22.

TD

[Maus92]

Naval aviation has been a whole lot safer in the past 40 years or so mainly due to twin engine aircraft. The argument that two engines double your chances for an engine failure could just as easily be construed as doubling your chance for survival.

[Willard Whyte]

Had the airframe been designed around only Air Force and Navy requirements, you would have seen a two engine aircraft, pencil like fuselage, plenty of speed and un-compromised stealth characteristics, but smaller and more agile than the F-22.

And quite probably with all 3 versions in service by now too.

[althenick]

Quote:
Had the airframe been designed around only Air Force and Navy requirements, you would have seen a two engine aircraft, pencil like fuselage, plenty of speed and un-compromised stealth characteristics, but smaller and more agile than the F-22.

And quite probably with all 3 versions in service by now too.

I some how doubt it...

The P.1154 story (http://www.harrier.org.uk/history/history_p1154.htm)

More specifically ...

As the design of the P.1154 was adapted to meet the needs of the two Services the respective variants diverged from each other to an ever-greater degree. The preliminary brochure submitted in August 1962 saw the RAF and Royal Navy aircraft as being 80% common. By the time of the more detailed brochure of May 1963 the situation had reversed, with only 20% commonality between the two designs. This growing divergence was mostly caused by the Royal Navy's demands. AW406's insistence on two seats, large AI radar and two-shock inlets to achieve Mach 2 at altitude led to considerable weight growth, necessitating larger wings, while the catapult requirement led to a new undercarriage layout. The waters were further muddied by a Rolls-Royce proposal to substitute twin Spey engines, modified to use vectored thrust and PCB, in place of the BS.100. Despite all this, the design for the RAF remained fairly constant, being essentially the same as that proposed for NBMR-3. While the naval aircraft remained fluid, Hawker began detail design and mock-up construction of the RAF variant.

Also talks about a catapault variant!

[Willard Whyte]

Not what I meant.

Should've written all three 'types'. But then I suspect you knew that...

[Wander00]

I'll believe one engine is safer than two when they authorise single engine ETOPS!

[Courtney Mil]

I agree, Wander. There seem to be a lot of folk here that confuse safety with probability of failure. Single engine, lower probability of failure, far more of a safety issue when it happens. Simples.:ok:

[t43562]

I sometimes wonder how it is possible to stop ones enemies from knowing what the capabilities of some aircraft are. There seems to be so much public domain knowledge. I presume that you want them to believe it's either better or worse than it really is so that their planning cannot cater for it adequately. If I was in charge of this now, I'd want to create lots of doubt in every direction - confusing comparisons of price and performance which don't add up. At the same time one must convince the public that their money isn't being wasted. Seems like a very difficult job to me.

Another thought that struck me was that it's great to have a big, late, wildly overbudget programme in which one might be able to hide spending that's really aimed at something else. Not that I'm suggesting this is the case now - I just can't help but think it.

[Typhoon93]

From everything I've read about this aircraft, it does seem a bit crap. Lockheed Martin is trying to do too many things without first establishing what the package is good at.

The F-15 Eagle is a superb aircraft, it's fast, it turns very well, it's very good for gaining air superiority and holding air superiority (isn't that the point of a fighter?), it can be flown high or low depending on the mission and it can even be a good close, fast air support weapon for troops on the ground. Most importantly it has been tried and tested in front line combat both air-to-air and for ground strike roles and it has dominated, I don't believe a single aircraft has been lost in air-to-air engagements. In my opinion it's the perfect fast jet, although I am slightly biased as it is my favourite.

The F-15SE is an upgraded version, plus it has stealth capabilities. It's also a lot cheaper. So why did the MOD decide to go with the F-35's as one of our main air assets when there are other, cheaper, and proven more effective options? The F-35's will be great for defending the fleet, I have no doubt. Although I can't understand why the MOD have ordered these aircraft to work alongside the Typhoon in both conventional roles and carrier-based roles. There is no logic there for me.

If you're going to hybridise a bomber/close support aircraft with a fighter, then in my view it would be good logic to go with something that already works and is known to work. In the process you'd save a lot of money.

[ColdCollation]

And, er, what mark of Spitfire would we have been on by now? :ugh:

[Courtney Mil]

The swept-wing, twin-engined, twin-tailed, AESA, single-canon, 4x4, Spifire XXXIV. Obviously.

[LowObservable]

T93 - Back when the main JSF decision was taken in 2000-01:

The F-35 was supposed to be in service by now, cost about half as much to acquire and operate as now seems likely, and weigh 2000 pounds less empty into the bargain, even with a 9 g airframe.

STOVL was supposed to be the magic trick that made it possible to have a sub-50000-ton carrier, which would be much less expensive than a Catobar carrier.

The Typhoon looked comparatively expensive and was still struggling with some basic technological issues.

So the decision was based on valid data at the time.

[PhilipG]

CM surely we would be buying Seafires not Spitfires, for the aircraft carriers, totally agree as regards the marque etc....

[Typhoon93]

Thanks LO.

Do you agree with the current UK trend to have aircraft with multiple roles?

Should we go back to bombers and specialist close (ground) support aircraft like the B-1 and A-10, and leave the fast jets with huge wings for possible air-to-air engagements, or a show of force to the enemy?

[Courtney Mil]

T93, good questions, but you seem to have burst upon the scene with some slightly grand ideas, reminiscent of some of our past members.

You tell me. Do you think F-35B can take on all the roles of dedicated fighters, strategic and tactical bombers, CAS, recce, SEAD, etc, etc?

Discuss...

[typerated]

Typhoon93.


I was going to ask what planet you are on. But now I see you are 21.


Perhaps improving your knowledge could come before posting?

[Courtney Mil]

Philip, no. We'd have a dedicated XXXIVb for carrier work. Same but with one of the engines, gun, a tail, a load of wing area, hook and fuel capacity removed. But they'd have covered it in magic plastic to make it invisible.

[Typhoon93]

Yes Courtney, I guess it could be, and it seems that other aircraft have already been used for multiple roles.

It's quite interesting how a single package can be used for different things, although should it be?

[Hempy]

Courtney, I've been informed that in the modern age, the number of posts a forum member has is apparently proportional to said members implied credibility (much like other modern day institutions where the number of words someone says carries more weight than someone elses experience...). Hence why we see our newer members attempt to get a post or two on every single thread in the forum, regardless of the merit of the post itself. T93 isn't on his lonesome in this regard, but it always sort of screams 'walt' to me when I see it happening.

I've not heard from Engines or the others lately, what is the current state of affairs regarding the F135? A little bird tells me there is go/no go decision to be made regarding the engine and a no go is a potential 'show stopper'.

Any truth on a serious redesign? Is this even viable this late in the project or has the Hydra already grown too many heads to kill?

[GreenKnight121]

I suspect that if P&W has to do a major redesign that RR and GE will step back into the picture with their F136 design*.


* That never should have been canceled in my view.

[Maus92]

I'm rereading "The Air Force and the Great Engine War" by Drewes. It seems that Pratt has not fundamentally changed its business culture. The F100 was having issues - potentially grounding both the F-15 and F-16 - yet Pratt spent more time trying to derail a competitive engine than fixing the problems. Sounds eerily familiar.

[Courtney Mil]

That was the early F100-PW-100 engines. Like this, the problems were due to the advanced nature of the engine and the massive step up in power to weight from anything produced before. Those issues were solved without a major redesign and it may well be that F-135 will go the same way. A component refinement could be the answer. As yet we don't know. I wouldn't write P&W off just yet. This is a very challenging design.

What I would still wonder about is the version in the B model, with massive load from engaging the lift fan. I know it's been flying for a while now, I would love to hear if anyone has any thoughts on what might crop up with it.

Edit: I should mention that I have many hundreds of hours in front of 2 F100-PW-100s. Apart from the JFS (jet fuel starter) they were sweet.

[Turbine D]

What I would still wonder about is the version in the B model, with massive load from engaging the lift fan. I know it's been flying for a while now, I would love to hear if anyone has any thoughts on what might crop up with it.
TBOs will be shortened. Hope there is a plan to have plenty of spare parts and additional engines available nearby…

[Courtney Mil]

"Hopefully" indeed.

[Turbine D]

Courtney,

I should mention that I have many hundreds of hours in front of 2 F100-PW-100s. Apart from the JFS (jet fuel starter) they were sweet.
You might have felt slightly different if you were seated over one F100-200 in an F-16. Originally, the problem was compressor stalls when operating within the flight envelope, which got fixed, but the real driver for the USAF to bring on the F110 engine were HPT blade failures that P&W had a hard time eliminating in a timely manner. It had to do with the basic turbine blade material used and accountability for presumed casting defects during the design phase.

[Courtney Mil]

Oh, yes, I'm sure I would have done. Apart from anything else, a good input to the 1 v 2 engine debate. Was it an increase in pressure ratio or purely a materials issue? It sounds like there's more to this. :ok:

[LowObservable]

I was close to Engine War 1 in the early 1980s. Every time I braved the gators in the parking lot and visited WPB, Pratts were sure they had it sorted. Changes in scheduling. Inspections. Fadec... I don't recall all the details and the notes are in storage, but it was not until GE was seriously funded that they got religion and made the -220 and the -220E upgrade kit.

Some good material here:

http://www.dtic.mil/dtic/tr/fulltext/u2/a282467.pdf

As for the current issue, the longer it drags on the worse it looks.

[John Farley]

What I would still wonder about is the version in the B model, with massive load from engaging the lift fan

Hi Courtney

You may know what follows but for the benefit of others....

The fan is connected to the engine by a clutch as part of the computer controlled 'conversion' process of the whole aircraft to the STOVL mode. It is done at low engine power. Once the motor car type clutch slip has spun up the fan in this low power configuration some pins are fired into the clutch plates locking them up into a positive mechanical drive condition. Only then is the now semi 'turbo prop' type engine given its head.

[LowObservable]

Let's not be tough on T93 - he writes like one considering his future. And the one-multi-role-type argument versus the several-single-role-type argument is one that the experts have banged their heads against for decades.

For instance, which equivalent-cost air force would you prefer: 100 F-35s, or 60 F-35s and 80 JAS 39Es?

[typerated]

Well you have more patience the me LO!


I totally agree on the numbers game. It seems we are in a death spiral of:


1) " we are getting short on numbers, better make sure that the kit we buy is multirole"


2) " these multirole machines are expensive to buy and keep going, shame we can't afford many of them"


Goto 1


In many ways I think the USAF is heading for a train crash. They have been keeping kit past its sell by date and now have many platforms they would like to replace soon - KC-135, T-38, B-52, B-1, B-2


Throw in F-15/16/ A-10 all to be replaced by the wonder jet and that the budget is shrinking and something will have to give.


Probably numbers in a big way?


I am sure some in the light blue are sympathetic to the idea of buying a light (cheap) fighter for (the majority) of jobs where stealth is not needed.


Perhaps a Hi (F-22)/ Mid (F-35)/ Low (Gripen) Mix

[LowObservable]

Of course, now that so many F-35s have been ordered, the competition is preaching the benefits of mixed/diverse fleets and Team F-35 is going on about the economies of scale. They have to, because the F-35 that rolls off the line today is extremely expensive.

However...

Aircraft manufacturing is an interesting business that is low-volume at best. The highest-rate aircraft lines in the world are almost an order of magnitude lower in rate than Lamborghini or RR Motors.

Aircraft are largely hand-assembled from parts that made in very similar ways from one aircraft to another and often come off the same supply chain. The key to reducing costs is keeping things simple, holding the parts count down, managing the supply chain well and keeping assembly efficient - but that means "lean" rather than a huge automated Toyota-type line.

In the olden days, too, keeping aircraft flying involved a big engineering infrastructure that you did not want to duplicate (by adding an extra type) unless you had to. Digital engineering data and parts tracking, and high-speed delivery, make that less of an issue. (There aren't many airlines any more that standardize on one manufacturer's jets.) So a mixed fleet may be less of a burden than it once was.

[Turbine D]

Courtney,
Was it an increase in pressure ratio or purely a materials issue? It sounds like there's more to this.
The F100 problem of stagnation and/or stall could be certainly related to nuances of a higher pressure ratio engine and not having the experience as to cause and what the fix ought to be. Keep in mind that GE had a very sound and well tested high pressure engine in the F101 with a good stall margin from which the F110 evolved. The material issue came along as the F100 morphed into higher thrust versions to match the thrust of the F110-100. This entailed using new materials and advanced casting processes such as DS (directionally solidified) and then SC (single crystal) in the production of turbine blades. GE was able to not launch into these advance processes and materials as early as P&W did and therefore had time to avoid some pitfalls P&W incurred. The F110-100 engine was unique in that engine power was controlled by measuring the actual temperature being experienced by the HPT blade, not EGT. If the temperature got too high, fuel flow was reduced accordingly.

LO,
Thanks for the "good material", it was an interesting read and history recall.
I was close to Engine War 1 in the early 1980s.
So was I and into the 90s.

Fast forward to the F135 engine on the F-35. P&W had good engine knowledge going in considering the real time experience gained on the F-22. I suspect that changes to save weight and other enhancement considerations have lead to the problem/problems currently being experienced on the F-35 engine. I can't help but think the fixes may not be so simple by the silence of the L-M normal propaganda as well as the DoD's silence.

[Vendee]

The material issue came along as the F100 morphed into higher thrust versions to match the thrust of the F110-100. This entailed using new materials and advanced casting processes such as DS (directionally solidified) and then SC (single crystal) in the production of turbine blades.Surely directionally solidified blades were not exactly new technology at that time? They were first used in 1969.

The F110-100 engine was unique in that engine power was controlled by measuring the actual temperature being experienced by the HPT blade, not EGT. If the temperature got too high, fuel flow was reduced accordingly. I'm not sure about unique. The RB199 first ran about seven years earlier and used optical pyrometers to read blade temps and to control fuel flow accordingly.

[ORAC]

A hypothesis.

The F135 has no margin left, in fact the main point of the F136 was the performance margin for growth in the design. A weight increased on the F35 they increased thrust by thrust by pushing the engine to the limit - but the stealth design limits the heat absorption limits of the airframe so that it can't disperse any more, so the main engine components are running at or beyond design limits - and it looks like they can't take it.

Developments for the next generation engine might help - eventually - but only with a major slip and redesign/cost. In the short term the question is what level of heat/thrust is acceptable to maintain a minimum acceptable TBF.

IRRC the original Tornado F3 RB199 engines were having to be changed about every 70 hours till the Saudi funded replacement blades were fitted...

[Vendee]

IRRC the original Tornado F3 RB199 engines were having to be changed about every 70 hours till the Saudi funded replacement blades were fitted That is feasible. I remember that in 1987 on the lower thrust RB199 Mk101, the average time between HPT blade failure was 124 hours. The Mk 103 and Mk 104 produced more thrust (higher blade temp).

I can't remember when single crystal blades were introduced to the Mk103 and Mk104 engines but I know that they all had them by the start of GW1. They made a huge difference with 300 hours being easily reached. I found myself briefly back on Tornado a couple of years ago and some engines were managing 1000 hours.

[LowObservable]

Orac & TD...

Those observations correlate. Also consider that there have been known redesigns to various parts of the engine, that may have induced different loads and temps downstream.

[sandiego89]

Looks like a B has done some cross wind and wet runway trials at Edwards AFB. Looks like a pretty good cross wind from the approach shots- a good amount of crabbing and it is interesting to watch the control surface movements.

http://www.youtube.com/watch?v=XEfnj9yJH6M

The "bin lid" on top still looks so wrong....

[LowObservable]

Up to 120 knots? That really puts the R in RVL...

[Lonewolf_50]

Looks like a B has done some cross wind and wet runway trials at Edwards AFB. Looks like a pretty good cross wind from the approach shots- a good amount of crabbing and it is interesting to watch the control surface movements.

F-35B Wet Runway and Crosswind Landing Tests - YouTube (http://www.youtube.com/watch?v=XEfnj9yJH6M)

The "bin lid" on top still looks so wrong....
Not wanting to be a wet blanket, amigo, but for the money we are paying for this aircraft, that sumbitch needs to be able to dance the jig on final and grease it on anyway, regardless of cross wind. :p The reporting of the mundane sometimes rubs me the wrong way. Not really aimed at you, I hope you understand.

GreenKnight: I suspect that if P&W has to do a major redesign that RR and GE will step back into the picture with their F136 design*. That never should have been canceled in my view. Yes, on both counts.


LowObservable: Many thanks to the DTIC link for the F-100 F-110 article. Most informatieve. :ok:

[sandiego89]

Not wanting to be a wet blanket, amigo, but for the money we are paying for this aircraft, that sumbitch needs to be able to dance the jig on final and grease it on anyway, regardless of cross wind. :p The reporting of the mundane sometimes rubs me the wrong way. Not really aimed at you, I hope you understand

I didn't take it personal, I understand, I know it is a PR release but thought it was a clip worth mentioning. There are plenty of folks (including on this thread) who moan about all things it hasn't done yet, but it seems more blocks are getting checked off....

Will it ever dance like a Harrier? Perhaps not, or as easy as JF made it seem :D.

I find the different modes interesting, and how each is designed to make things easier for the pilot, but as I said in an earlier post, I fear the day when the computer "thinks" it is in a certian mode, but the pilot or the controls or engine is thinking something else.

[Rhino power]

There are plenty of folks (including on this thread) who moan about all things it hasn't done yet...

Folks have every right to 'moan' given the eye-watering cost of the programme, which may well become even more eye-watering given the F135 travails...
And as to 'things it hasn't done yet...', first flight was December 2006 so, coming up on 8 years of test flying and still restricted to the kind of flight envelope you'd expect of 30 year old, utterly knackered airframes which are due for retirement!

-RP

[typerated]

RP,


You don't read the Daily Mail do you?


Just for comparison the first production Typhoon didn't fly until 9 years after the prototype.

[Hempy]

RP,


You don't read the Daily Mail do you?


Just for comparison the first production Typhoon didn't fly until 9 years after the prototype.

Now that is a little disingenuous typerated...the Typhoon was 9 years between the prototypes first flight and the mature aircrafts operational acceptance. Even then the delays (54 months in total) were political, not mechanical.

How far is the F-35 from operational
acceptance?

[typerated]

Hempy,


Next Year!


Pentagon: First F-35s Operational in 2015 | Defense News | defensenews.com (http://www.defensenews.com/article/20130531/DEFREG02/305310021/Pentagon-First-F-35s-Operational-2015)


I am no fan at all of the F35 and its dramas but its progress is quite swift compared to Typhoon (even without the Germany delays). I think you are very kind to assume it was operational when the first production aircraft flew. Of course F35 is following a very different development/procurement path.

[LowObservable]

TR - To be entirely accurate, "operational" in this case means one squadron of interim-standard aircraft, primarily capable of fixed- or relocatable-target attack and ill-equipped either for the operator's primary mission (CAS - no gun, 500/1000 lb bomb only, no Rover) or for counter-air (no gun, 2 x AMRAAM only, transonic).

That's if they make 2015, which is increasingly in doubt as the latest "one-off problem" (:O:O:O:O) drags on.

[Turbine D]

Quote by Hempy: the Typhoon was 9 years between the prototypes first flight and the mature aircrafts operational acceptance. Even then the delays (54 months in total) were political, not mechanical.
It will be interesting to see politically what happens when the US Congress returns from their vacation. One of the first items of business will be the budget. Without an overall budget another defense sequester cut will take place. The Congressional folks that review the proposed defense budget have made it clear they will not approve the USAF budget due to elimination of the A-10 Warthog. If this happens as advertised, it will put additional pressure on financing the F-35 program according to the Pentagon gurus. Should be an interesting month or two ahead, both technically and politically for the F-35.

[PhilipG]

There is some interesting logic in what the USAF are saying, we need F35 to replace one for one all sorts of different types of aircraft, including A10s, then to fund the over budget F35 development costs we want to annoy Congress by suggesting that we will take out of service the A10, implicitly shrinking the USAF and its footprint in a number of states. There is an implication that they may want to expand aircraft numbers later, if the final procurement numbers for F35As are to be achieved.

Or is the USAF saying, not yet publicly, that the final procurement number is being reduced as there will not be so many squadrons to re equip and in any case the budget has been sequestrated again? So the unit price will continue to rise. Interesting times.

[Wander00]

If one had to make a logical decision based only on cost and effectiveness, would we keep this potential turkey. I guess not, but then only IMHO

[Lyneham Lad]

Another hint to get a move on with the F-35...
Flight Global - USAF grounds 82 F-16Ds due to new cracks (http://www.flightglobal.com/news/articles/usaf-grounds-82-f-16ds-due-to-new-cracks-402853/?cmpid=NLC|FGFG|FGFIN-2014-0826-GLOB&sfid=70120000000taAh)

The US Air Force announced late on 19 August the grounding of 82 of 969 Lockheed Martin F-16s still in service after finding structural cracks.

The grounding, which involves only the two-seat F-16D, could be lifted to allow aircraft to fly a limited number of flight hours with a temporary fix, the air force says.

Engineers are still analysing options for a permanent repair, the air force says.

The cracks, which were discovered in post-flight inspections, damage the canopy sill longerons in a space between the front and rear pilot seats, the air force says.

Longeron cracking caused a Boeing F-15C to disintegrate in flight in Novemeber 2007. That event triggered a grounding, fleet-wide inspection and lengthy repair.

The grounding underscores the air force’s aging inventory of fighters, as the service waits for the delayed entry and production ramp of the Lockheed F-35A. The 157 F-16Ds still in service are 24 years-old on average with 5,500 flight hours.

Lockheed is already performing a cycle of structural fatigue testing on an F-16 Block 30, which is unrelated to the inspections that discovered the canopy sill longeron cracks.

The fatigue tests are aimed at determining what structural modifications are necessary to extend the life of hundreds of F-16s by 10-15 years, depending on how long it takes for the F-35A to start replacing the fleet.

[Courtney Mil]

They knew about that already. Good idea about getting on with the F-35. I wish they could.

[Rhino power]

Norway set to receive first drag-chute equipped F-35 - 8/22/2014 - Flight Global (http://www.flightglobal.com/news/articles/norway-set-to-receive-first-drag-chute-equipped-f-35-402965/)

-RP

[LowObservable]

LL - $90 billion plus has already been spent on getting on with the F-35. If it had been successful the AF would be replacing F-16s at a rate of >100/year and these older C/Ds would have been retired.

[Radix]

............

[ORAC]

USAF Chief: Pratt Close To Developing F-35 Engine Fix (http://www.defensenews.com/article/20140828/DEFREG02/308280040/USAF-Chief-Pratt-Close-Developing-F-35-Engine-Fix) :ugh::ugh:

So they're close to performing a test of a potential fix to the problem - though they're still not sure if it's a design or manufacturing problem.

Only definite statement to be found in there is: "“We are very concerned, because it is a developmental program still, and we do not want it to ever happen again,” Welsh said........

[GreenKnight121]

In February this year they declared that the "latency problem" was a "non-issue" and "never as bad as feared".
Additionally, problems with jitter had been solved and what little latency was there had been reduced further.

F-35 Test Pilots Will Begin Flying ?Gen? Helmet Display | Aviation International News (http://www.ainonline.com/aviation-news/singapore-air-show/2014-02-08/f-35-test-pilots-will-begin-flying-gen-helmet-display)
The helmet system’s latency, or response time at importing DAS imagery–measured in milliseconds–was not the problem testers thought it would be, Kelly said. Pilots just hadn’t had the opportunity to use the DAS sensor array during flight testing. “Initially there was concern about the latency of the DAS and what that might look like,” he said. “But we were able to do some testing in the spring and summer of 2013 where we looked at a bunch of different tasks [and] some formation flying and, across-the-board, we found there was really no issue with the latency.”And in July this year the helmet was declared ready for service.
?Magic Helmet? for F-35 ready for delivery | Ars Technica (http://arstechnica.com/information-technology/2014/07/magic-helmet-for-f-35-ready-for-delivery/)

[Radix]

..........

[LowObservable]

You can always fix the rubbing by opening out the clearances. Simples. But you take a hit on efficiency and performance, unless you raise temperatures and suffer on durability and thermal issues.

[CoffmanStarter]

All said and done ... the F-35 Sim looks like fun :}

http://www.lockheedmartin.co.uk/content/lockheed/us/products/f35training/_jcr_content/product_image.img.jpg/1375720347150.jpg

F-35 Lightning II Training Systems · Lockheed Martin (http://www.lockheedmartin.co.uk/us/products/f35training.html)

I've already stuck it on my 2014 Christmas List ... I reckon there's enough room in my garage ... Might need to up-rate the power supply though :E

What no 3D mini worlds and gantry mounted cameras :8

[gr4techie]

^ I hope the Airforce did not pay $millions for that sim. You can get it for free on the iPhone :-) https://itunes.apple.com/gb/app/modern-jet-fighter-combat/id639358230?mt=8

[glad rag]

P M S L at that :sad:

[Hempy]

The sad (but certain) part is that you can program anything in to a computer e.g all the systems actually work! :rolleyes:

I hope they have modelled appropriate engine fail procedures into their awesome simulator!!

[CoffmanStarter]

Cor blimey guv'nor they've only gone and stuck an F-35 on the 18th Tee at Newport ... That's Newport South Wales :}

https://s3.yimg.com/bt/api/res/1.2/Xl3HLq8IGoD3nAKXg9PeOQ--/YXBwaWQ9eW5ld3M7Zmk9aW5zZXQ7aD0zMzU7cT03NTt3PTUxMg--/http://media.zenfs.com/en_us/News/Reuters/2014-09-03T155824Z_1996883902_GM1EA931UH101_RTRMADP_3_NATO-SUMMIT.JPG

Image Credit : YVES HERMAN/REUTERS

A model of an F-35 is seen parked in front of the Celtic Manor golf club ahead of a NATO Summit near Newport in Wales

More here ...

https://ph.news.yahoo.com/photos/model-f-35-seen-parked-front-celtic-manor-photo-155824240.html

[glad rag]

Hmm. Now that is a bit, well, S.A.D.

[500N]

I do agree, that is a bit sad.

Might have had a bit more oommpphh if the F-35 had got here last month.

[Lone_Ranger]

Par for the course innit..... It may be a NATO meeting, but only the U S of A has a model of a fighter jet parked on a golf course ..sorry but you really are a nation of arrogant arsewipes

[Just This Once...]

In UK markings….

[500N]

In UK markings….I would have thought having all the partners on the side would have been a better look.

[Coochycool]

I'd have thought that something actually in service on time and on budget might have been even better......

[Maus92]

At least they know where the attendees will be spending their time...

[500N]

Probably oogling Australia Foreign Minister on her morning jog ;)

Julie Bishop is her name.

[glad rag]

...................Eh?

[500N]

I was referring to this statement
"At least they know where the attendees will be spending their time... "

Julie Bishop is intelligent, fit and attractive and as has been shown can more than hold her own against Putin
and others (as in stare down as she did recently).

[CoffmanStarter]

I understand that a max Crazy Golf score is achieved if you loft the ball down the starboard intake ... complete two revolutions around the lift fan ... and then exit aft through the tailpipe into the hole :E

[FODPlod]

I like the way one vehicle is camouflaged for bunkers and the other for the fairways and greens:http://i3.walesonline.co.uk/news/wales-news/article7713494.ece/alternates/s2197/JS45377349.jpg

[FODPlod]

The Typhoon kit being assembled:http://i4.walesonline.co.uk/news/wales-news/article7711863.ece/alternates/s2197/14932170517_b6224f19d9_k.jpg
Full article and pictures here: NATO Summit 2014: Behind the scenes at the NATO hotel - Wales Online (http://www.walesonline.co.uk/whats-on/arts-culture-news/nato-summit-2014-behind-scenes-7712760)

[GreenKnight121]

So much for Lone Ranger's screed - ha ha.

[TBM-Legend]

Par for the course innit..... It may be a NATO meeting, but only the U S of A has a model of a fighter jet parked on a golf course ..sorry but you really are a nation of arrogant arsewipes

Speaking of bigots please see writer of above...:D

[TBM-Legend]

Love those new golf buggies....:ok:

[ORAC]

F-35 Head: Delays Coming if Test Planes Grounded Through September (http://www.defensenews.com/article/20140903/DEFREG02/309030029/F-35-Head-Delays-Coming-Test-Planes-Grounded-Through-September)

WASHINGTON — The head of the F-35 Joint Strike Fighter program is warning that there is a real danger of missing deadlines if his test fleet of aircraft are not flying regularly by the end of September. “I need all of [the test airplanes] back to full envelope by the end of this month,” Lt. Gen. Christopher Bogdan said at Wednesday’s ComDef conference in Washington. “Otherwise we will start seeing some delays in future milestones.”

However, any retrofit needed to the F135 engine at the root of the restrictions will be borne by contractor Pratt and & Whitney rather than taxpayers.

The entire F-35 fleet were placed under restrictions following a June 23 fire that heavily damaged an F-35A conventional takeoff-and-landing model at Eglin Air Force Base, Florida. Since then, the small test fleet has had some restrictions relieved, but is still not allowed to operate at full capacity. While insisting that the Marines remain on track to take the F-35B jump-jet variant operational next summer, Bogdan said there has been a “headwind” of about 30- to 45 days added to test points due to the restrictions. Testing the Navy’s F-35C model at sea is one of the tests affected by potential delays. “Can we make some of that [time] up? Yeah I think we can,” Bogdan said. “But we have to get all of those airplanes up and flying again.”

The cause of the fire was identified as “excessive” rubbing of a fan blade inside the F135 engine, designed and produced by Pratt. Bogdan went into further detail for the first time on what actually happened to cause the damage.

The issue began three weeks before the fire when a pilot took the aircraft up and executed a two-second maneuver involving adding Gs, roll rate and yaw to the plane at the same time. Although that move was ““well within the envelope of the airplane,” Bogdan said, those two-seconds led to the engine rubbing against a rubber piece at a much higher rate — and nearly double the temperature — than it was designed to do. In turn, that led to what Bogdan called “microcracks” that went unnoticed until the day of the fire. “Over the next three weeks of that airplane flying, those microcracks started growing in what we call ‘high cycle fatigue,’” Bogdan explained. “And eventually on the day this happened, that fan-blade system just cracked too much, the whole circular part of that engine — through centrifugal force — stretched out and became a spear; that spear went up through the left aft fuselage of the fuel tank and it was the fuel tank that caused the fire.”

An investigation is still ongoing into the root cause of the issue to discover whether it was a production or design flaw, Bogdan said his team has narrowed down the cause to four sources and should have the results by the end of the month. He also noted that while no microcracks were discovered in other jets, there were marks that indicate potentially similar, if lesser, issues.

That leaves the question of how to make sure this problem doesn’t crop up again. Bogdan laid out how his office is moving forward with potential retrofits to the engine.

The first step involves taking a new engine and slowly working it through its paces to get it through the “burn in” phase. Bogdan indicated that testing would begin in the next two weeks, and if that two-sortie process works, it can be replicated for the test fleet.

The second step is more dramatic, requiring a redesign of the F135 to include what Bogdan described as a “pre-dug-in trench” into the fan section to separate the rubber and the fan blade in that part of the engine.

Gen. Mark Welsh, the Air Force Chief of Staff, told Defense News in August that a redesign could be coming for the engine, but Bogdan revealed that they intend to develop a prototype engine for that potential solution. For fielded airplanes, the Air Force could replace the fan section with the new, pre-trenched fan section in the engines — a relatively painless procedure that could be done in depot.

Pratt & Whitney has agreed to cover the costs of the retrofit engines for the F-35 fleet, a move praised by Bogdan. “I will tell you that Pratt & Whitney’s reaction to this problem, from my opinion, has been very good. They clearly recognize this is a problem they need to solve,” Bogdan said. “Pratt has said whatever the cost of retrofitting that 156 airplanes is, ‘that will be ours to bear.’”

The general also indicated that the cost for retrofit will not be “very great,” but declined to offer a general cost estimate........

[Eul0gy]

Pratt & Whitney sues supplier of titanium used in F-35 engines - 9/3/2014 - Flight Global (http://www.flightglobal.com/news/articles/pratt-amp-whitney-sues-supplier-of-titanium-used-in-f-35-403306/)


The sole manufacturer of engines for the Lockheed F-35 Lightning II discovered in May 2013 that it had used substandard titanium alloy that might have been illegally purchased from Russia.

Pratt & Whitney halted delivery of F135 engines that contained the suspect titanium and has subsequently sued the supplier, A&P Alloys, of West Bridgewater, Massachusetts.

Titanium is popular in aircraft manufacturing for its strength and light weight. In May 2013, P&W learned a majority of an order of 900 pieces of the metal was originally melted in Russia, according to the lawsuit filed on 29 August in the US District Court of Massachusetts.

The discovery last year of conflicting documentation of the metal’s origin resulted in a “quality hold” on delivery of the F135 engine, the company says. The titanium was used to manufacture some parts used in engines made by Pratt & Whitney Canada.

[Turbine D]

The titanium issue has no direct connection to an engine fire that caused the F-35 fleet to be grounded this spring and miss a pair of major European aerospace shows. The fire, officials concluded, was caused by fan blades rubbing.
The part for which the titanium was used is called a fan-variable vane arm and had already been installed in more than 100 engines. The existing parts are to be replaced during regular maintenance at Pratt & Whitney's cost.

General Bogdan said the natural “flex” of the mishap engine under high-G conditions caused fan blades to “rub” and “dig too deep” in the rubber-like seal around the power plant.

Hmm, may take a little doing to stop the flexing of the engine inside the current flight envelope. Keep in mind the flight envelope has been reduced from what was originally expected and promised.

[sandiego89]

What really galls me is the lack of proper kit for the UK pilots, surely the MoD can do better to properly outfit their crews, just look, no gloves, non-fire resistant coveralls, and the much hyped sensory helmet looks rather austere.

http://www.westerndailypress.co.uk/images/localworld/ugc-images/276309/Gallery/images/21444897/6300198.jpg

[Fox3WheresMyBanana]

Just as well it's a sidestick....


returning to the engine issue, won't any "pre-dug-in trench" reduce efficiency and so increase fuel burn?

[sandiego89]

So much for Lone Ranger's screed - ha ha.

Indeed.

And just so I have it correct, according to Lone Ranger standards, then everyone in the UK is also "arrogant arsewipe" with the Typhoon on display? Or maybe everyone in Germany, Spain and Italy and the UK, since it is a multi-national program? Just curious. :yuk:

http://cache2.asset-cache.net/gc/454535030-police-officers-stands-guard-near-to-a-model-gettyimages.jpg?v=1&c=IWSAsset&k=2&d=GkZZ8bf5zL1ZiijUmxa7QSUHJ1%2B19fYO2rwT4LGNXFyLxyo%2FPfxmxl GzbQxbKYre

[Typhoon93]

Apparently the Typhoon is a replica, but to me it looks like the real deal with the ribbons of the safety pins for the weapon systems and landing gear clearly visible, especially from the news footage. Can anybody confirm if it is indeed a replica or a real aircraft?

Second question: How would they get a real fixed wing aircraft in there? At 12 tonnes, I would have thought it's a bit too heavy for the Chinooks? Even if it wasn't, at ~£80 million a piece I'm surprised the RAF would allow that.

[melmothtw]

Can anybody confirm if it is indeed a replica or a real aircraft?


If you look at some of the links previously posted in this thread you'll see the replica kit being assembled.

Second question: How would they get a real fixed wing aircraft in there?

They can't, it's a replica.

[Lonewolf_50]

Par for the course innit..... It may be a NATO meeting, but only the U S of A has a model of a fighter jet parked on a golf course ..sorry but you really are a nation of arrogant arsewipes That's pretty funny, considering the source. How about you get back on topic with the thread?

Interesting story on the titanium source and all that, but other than Pratt and Whitney doing the sort of thing that leads to why we require oversight of acquisition contracts, it doesn't seem to have moved the program any closer to being cancelled.

Perhaps its momentum has reached that critical value where nobody could stop it even if they tried.

[sandiego89]

it doesn't seem to have moved the program any closer to being cancelled.

Perhaps its momentum has reached that critical value where nobody could stop it even if they tried.

I think the cancellation point is well past, with over a 100 now off the line. Remember this thread title started 4 years ago, when the entire program was much more in doubt, but has become the all things F-35 thread. Perhaps a thread retitling is past due, but it seems we have gotten used to it on this forum.

[Typhoon93]

Thanks, MM.

[Turbine D]

returning to the engine issue, won't any "pre-dug-in trench" reduce efficiency and so increase fuel burn?
Probably, I think LO pointed out earlier, you could open up the tip clearances but sacrifice engine efficiency. The engine casings are the backbone of the engine. If the casings get too flimsy, backbone bending occurs. When that happens, things like third stage fan rotors (blisks) can rub. IMHO, increasing tip clearance is a Band-Aid, there is a more significant problem to be solved.

[PhilipG]

As I think many of us feel a solution to the engine problem has yet to be engineered and tested, that is if the real cause of the problem is known. I have read that P&W are going to repair all of the engines that are in existence at the moment, as has been stated well over 100 of them, quite an operation when the solution has yet to be found and the kits to implement the fix designed, produced and distributed prior to installation.

I assume that the Fort Worth production line is at best just making engine less planes, what this does to the in year cost of these LRIP aircraft could be interesting.

With the Marines wanting to declare IOC next year I assume that for this to happen they will have to have their initial squadron aircraft updated, is this really possible?

The carrier trials that the USN have planned for the F35C I suppose could be interesting and slightly prolonged if the engines have to be checked every three hours.

There are of course many other test points that may not be achievable with an aircraft limited as to what it can do.

Another year or so's delay in realistic IOC in my view, it transpires that it was a good move to delay the UK Aircraft Carriers for financial reasons some years ago.

[Fox3WheresMyBanana]

It only counts as a good move if it was done for that reason, which it wasn't. It was a fortuitous move.

-5i1cJIwE7M

[PhilipG]

Agreed, delaying the entry to service of the QEC Aircraft Carriers due to cash flow considerations now with the benefit of some hindsight looks to have been fortuitous....

[rh200]

What really galls me is the lack of proper kit for the UK pilots

And the skirt is way to long, makes it restrictive when maneuvering during unusual maneuvers.:E

[tdracer]

This seems like a bit of deja vu, all over again :=.


On the JT9D on the 747 and 767, we had problems with engine bending and compressor case distortion causing excessive tip rub, efficiency loss, and engine surge.


Again on the 747 and 767, the PW4000/94" had problems with compressor case distortion causing excessive tip rub, efficiency loss, and engine surge (it got so bad on the PW4000 that the FAA issued an AD, forcing Pratt to redesign the compressor and retrofit over 2000 engines with new compressors at a cost of several billion dollars).


So, now, on the F135 we have a problem with engine bending and case distortion causing excessive tip rub. Hum, I wonder what the common thread might be :mad::ugh:


BTW, I like the implication that wasn't that bad because it wasn't the engine that caught fire, it was the ruptured fuel tank. Yea, that makes me feel much better...:eek:

[megan]

Had a scan but couldn't see this postedThe microcracks in the third stage of the integrally bladed rotor that caused a catastrophic F135 engine fire in an F-35A on June 23 began forming three weeks earlier when a pilot conducted a fairly benign maneuver with a unique combination of yaw, roll and g stresses

F-35 Blade Microcracking Began Three Weeks Prior To Engine Fire | Defense content from Aviation Week (http://aviationweek.com/defense/f-35-blade-microcracking-began-three-weeks-prior-engine-fire?NL=AW-05&Issue=AW-05_20140904_AW-05_728&YM_RID=%27email%27&YM_MID=%27mmid%27&sfvc4enews=42&cl=article_1&elq=~~eloqua..type--emailfield..syntax--recipientid~~&elqCampaignId=~~eloqua..type--campaign..campaignid--0..fieldname--id~~)

[Turbine D]

Had a scan but couldn't see this posted

Think it's contained in ORAC's post #5143 from yesterday.

[LowObservable]

Evening all.

F-35 Fire: In Search Of A Solution | Technology content from Aviation Week (http://aviationweek.com/technology/f-35-fire-search-solution)

[Willard Whyte]

Ooh, now LO, I'm sure someone will come along and patronizingly, pompously, assert that everything is rosy up the '35's ass.

[LowObservable]

P&W has its say too:

Pratt & Whitney Offers Some F135 Explaining | Defense content from Aviation Week (http://aviationweek.com/defense/pratt-whitney-offers-some-f135-explaining)

Makes an interesting compare-and-contrast with their propaganda four-to-five years ago.

[Turbine D]

The F135 is the heaviest high-performance fighter engine ever built, weighing 70% more than the P&W F100 and measuring 24% larger in diameter, with consequently larger inertial and gyroscopic forces.
Therein the problem lies. Somehow, during the initial conceptual design, this observation wasn't sorted out properly. Although the engine is a heavy weight, the parts that need to be heavy don't seem to be heavy enough. The stator vanes are locked into the engine casing. IMHO, the integral bladed rotor and their seal teeth, being the best true diameter achievable, seem to be snagged by the stator vane seal grooves, not the other way around. Must have something to do with the engine casing true roundness in the air when the aircraft is maneuvering.

Bennett's dissertation can be condensed: We're good guys, thought we did everything right, didn't work out, don't know the root cause of the problem yet, working the issue, only 60% of the way to the end of development, not to worry, we will eat the added costs for this mishap… :hmm: Wonder what the future costs of spare parts will be? :eek:

[Fox3WheresMyBanana]

A weight penalty for the fix seems likely if there's a stiffness problem. Being a retrofit, it will likely be more than if they'd designed it right in the first place. This being a relatively cutting-edge engine, it may be simply a problem PW where unaware of, but there may be a PW designer somewhere shaking his/her head and saying "I told you so..."

[longer ron]

Turkey..... now about to become a heavier turkey .....
even I cannot joke about it any more... : (

How much to cut off the ski jump and install enough gear to operate a real carrier aircraft...shouldn't be too much..... even for 'shhhhh' - you know who !

[glad rag]

Turkey..... now about to become a heavier turkey .....
even I cannot joke about it any more... : (

How much to cut off the ski jump and install enough gear to operate a real carrier aircraft...shouldn't be too much..... even for 'shhhhh' - you know who !

"It is suspected that the fan blade began cracking three weeks before the fire during a complex manoeuvre in which the pilot put roll, yaw and g-forces on the aircraft simultaneously."

Engine cracks pose fresh delay risk for F-35B - 9/4/2014 - Flight Global (http://www.flightglobal.com/news/articles/engine-cracks-pose-fresh-delay-risk-for-f-35b-403350/?cmpid=NLC|FGFG|FGFDN-2014-0910-GLOBnews&sfid=70120000000taAm)

[NITRO104]

but there may be a PW designer somewhere shaking his/her head and saying "I told you so..."
Everything does seem to be screaming so...can't believe such dilettantism was let into the high profile project like this one though.
Still, I'm hearing about "engineers" on already alarming almost daily basis, capable of missing an order of magnitude when calculating loads, without even understanding the ballpark where their results should land, so who knows...

[RetiredF4]

"It is suspected that the fan blade began cracking three weeks before the fire during a complex manoeuvre in which the pilot put roll, yaw and g-forces on the aircraft simultaneously."It is suspected that the fan blade began cracking three weeks before the fire during a complex manoeuvre in which the pilot put roll, yaw and g-forces on the aircraft simultaneously."

Do I understand that correct, that such complex maneuvers (did we call those BFM once upon a time?) are not allowed with the F-35 and will break those engines?

[Rhino power]

Do I understand that correct, that such complex maneuvers (did we call those BFM once upon a time?) are not allowed with the F-35 and will break those engines?

The manoeuvre which is suspected of starting the fan blade cracking was also described as being 'benign' so, given the current G limit of the F-35 (still 3.5/4?), I think there is potentially even more bad news to come regarding this engine problem...

-RP

[Turbine D]

Do I understand that correct, that such complex maneuvers (did we call those BFM once upon a time?) are not allowed with the F-35 and will break those engines?
I think so. The F-35 really isn't a "fighter aircraft". General Bogdan pretty much alluded to this fact when he described the shortcomings he noted when assuming responsibilities for the program. The best definition as I see it is the F-35 is a gnat, not a fighter.

[Whitewhale83]

Yet the fanboys still insist that the 35 would defeat any current fighter if it came down to a WVR knifefight, mainly due to 'Fifth generation' (™) and 'sensor fusion' (™). But it would seem that currently the Lesser spotted fat Dave cant pull off manoeuvres that even WW2 pilots would have considered 'warming up'.

What is really interesting about the news coming out of P+W is that they hope to know the issue by end of Sept yet are still delivering engines that they will later have to recall and re-engineer once they have come up with a solution. At first it was suggested that it was a faulty batch of titanium, that seems to have dropped and now there is talk of designing in a 'gulley' for that set of blades or reinforcing the whole engine to eliminate flex, that is massive work.

We may never know how much this ends up costing but it is going to be a shocking figure

[Hempy]

Seriously interested in hearing from Engines about all of this. He seems to have disappeared off the planet lately..

The rumour of a serious engine redesign has been around for a while. What is Pratts position on this, what effect does it have on acceptance schedules, and what effect does it have on ongoing maintenance schedules/costs?

These are multi-million dollar questions. Along with the other unconnected issues with this aircraft, it's starting to look like an unmitigated disaster...

[CoffmanStarter]

F-35 Cancelled, then what ?

Well don't worry Chaps ... Our F-35 Desk Officer at the MOD has a Plan B ...

Pictures taken recently at a Top Secret Airbase in Berkshire, here in the UK, reveal the configuration of a totally new single seat Fighter design. According to well placed sources the design offers both Air Defence and Ground Attack capability ...

http://news.bbcimg.co.uk/media/images/77513000/jpg/_77513227_77498497.jpg

Image Credit : BBC News/Airbourne Aviation

Also seen in the picture is a further new aircraft design (in final stages of construction) which is believed to be the new StarBus M Falcon MRTT ... which is to be delivered under a further PFI contract to the RAF by StarTanker.

Coff.

[John Farley]

I must say I continue to be surprised at the negative attitude of many posters here following any information about development problems.

As I have said before, any event that shows up weaknesses at this stage of the programme is pure engineering gold when it comes to improving the eventual service standard of any aircraft type.

The F35 is a 60 year programme (that started in 2000) and we are only half way through the second decade.

I would predict that by the end of the next decade it will be well sorted giving 30 years when it will be the aircraft to beat.

[Bigpants]

John

Well put but is the aircraft going to offer value for money? Is it really the most cost effective solution for the UK?

I fear that Cameron's recent bold statement about keeping both carriers means they will be financially constrained to harbour most of the year and the F35 crews getting 150 hrs a year flying from UK ground bases assuming this aircraft gets a UK release to service.

We shall see but not optimistic about it being a 60 year programme. Would have thought UAVs more likely to take over sooner than that.

[RetiredF4]

John,
i respect your point, but i'm at a loss why those developement problems still exist in the second decade of the aircraft. The jet does not expand the flight envelope into regions totally unknown before. My old Rhino i started flying 1977 flew faster than M2, had 8.5 g's available, could shoot the gun, carry bombs and i never was able to overstress the airframe or the engines in a way that they quit on me.
We didn't have stealth, couldn't take off or land without a suitable peace of runway and our sensors and gadgets could't cope with the ones on later jets. Therefore to expect developement problems on those new areas is understandable, but airframe and engine problems under such a restricted flight envelope like the jet is operated at the moment are hard to understand.

The next question is, what kind of aircraft will fill the gap for the next decade, if you expect some more years until those problems are sorted out?

[LowObservable]

JF - The problem is that it's a lot of trust to put in a concept that is coming up to 18 years of serious-money development and $90 billion in SDD, with 90 production aircraft delivered. "At this stage" - in those terms - you should expect the design to be showing strong signs of maturity.

But even leaving aside engine troubles of the moment, it has yet to reach any form of IOC, fly with more than a few external stores, land on an aircraft carrier, deploy consistently away from main operating bases or be cleared outside a very restricted envelope for service pilots. It's also currently operating at 30-40 per cent readiness rate.

[John Farley]

Bigpants

You ask two very important questions and I have no idea of the facts that would enable them to be answered and I suspect all of the posters here are in the same position.

However this is PPRuNe so we can still offer opinions for what they are worth!

Dealing with value for money I don’t know how you judge the value of any defence expenditure until the period it is intended to cover is past! However a fair bit of the F35 programme money is being spent in the UK (we make back ends of all versions and the RR Lift System for the B) so that keeps people in high quality work plus they pay income tax etc. There has to be value in that. It also keeps our technology base at the leading edge of whatever is going on which has other potential advantages for the UK in the future. Personally I would not like to see us quit all that sort of activity.

As to the cost effectiveness of the B for the UK (assuming the carriers are there to enable our politicians to have their say around the world and they continue to want this) I am confident that the B is a much better choice than the C. Vertical landing is so much easier for the pilot. This makes operations safer with fewer training and currency demands. It also greatly expands the safe ship motion and poor viz operational envelope. Plus it requires only tiny fuel reserves compared with non VL operations. That is not just an opinion but fact. Many of the chaps who went to the Falklands were experienced catapult and arrested landing pilots and they all agreed that they would not have been able to operate in the conditions they found themselves in down there without VL.

In my experience it is hardly possible to overstate the reduction in stress on an approach if you can hover. For the approach to be successful (on land or at sea day or night) all you need to do is drift to a hover with the landing point in sight. You can then take out any lack of approach path accuracy with a bit of hover taxying. A minute in the hover is a very long time (ask any spectator bored by seeing nothing happening) hence the need for relatively tiny fuel reserves compared to normal fixed wing operations.

Going slightly off topic, I actually think the F35B spec (a supersonic and stealthy vertical lander) suits the possible UK carrier use more than it does the USMC for their primary expeditionary close grunt support role where I see the provision of supersonics and stealth as unnecessary – even unhelpful.

[John Farley]

RetiredF4

Therefore to expect development problems on those new areas is understandable, but airframe and engine problems under such a restricted flight envelope like the jet is operated at the moment are hard to understand.

I can appreciate why you feel that. However modern power weight and fuel consumption requirements make big demands on today’s developers. I don’t pretend to know anything much about the F4 but I have flown it. Sure it did Mach 2 but you had better be pointing towards base (and not far away) when you did it! As for combat endurance when the USMC stated ACM trials with their new low fuel consumption turbofan donks in their Harriers back in the early ‘70s they played until their adversaries bingoed and then waited on the range for the next lot to come out to play. That got up a few noses I seem to remember. The only point I am trying to make is that times move on, capabilities improve and this all costs time and money. Lots of it.

Your next question is about what kind of aircraft will fill the gap for the next decade.

I only know what the USMC (not the USAF or UN) have said which is that they intend to start winding down their Harriers between 2027 and 2030. 2030 would be 59 years since they started in 1971.

LowObservable

You are of course right with what you say - we just have a different view on whether those facts are to be expected or not.

Incidentally back in the early ‘70s when the USMC air combat aces had their first look at what their new AV-8As would do, they achieved pitch rates at low speeds which were twice what jet engines were designed to cope with in those days. So the gyroscopic forces caused the fan to rub much to everybody’s consternation and providing much food for the doom merchants of the day. Hey Ho.

[glad rag]

" It also keeps our technology base at the leading edge"

I wouldn't want to call an almost two decades old program "leading edge".

[John Farley]

glad rag

I don't know of a more modern western military aircraft programme. Therefore uncovering and solving problems on it seems leading edge to me.

[cuefaye]

JF


Typhoon. Ned Frith was right.

[Courtney Mil]

He normally was, cuefaye.

JF, the F-4 wasn't badly off for for fuel. We frequently did supersonic intercepts on those long exercise sorties and most of each intercept was most certainly pointing AWAY from base.

On your other point, Leading edge doesn't necessarily mean functional or successful. As this program is currently proving.

[ORAC]

The A-12 Avenger was leading edge, as was the RAH-66 Comanche.

[longer ron]

And the other consideration which is absolutely critical in the case of the 'B' is weight....any modification/redesign is going to be heavier !The 'B' is already heavy enough and does not have much 'spare' !!

[LowObservable]

And handling more weight means the equivalent of two engine redesigns, not one.

[Maus92]

Doesn't stop the Marines from wanting to order 6 more with OCO funds - funds that should be applied to actual overseas contingencies, like the renewed fighting in Iraq and possible actions in Syria. This backdoor maneuver was first floated last year, and I guess the Marines (and Lockheed Martin's lobbyists) are trying to slide this one in before the end of the fiscal year. The premise is to replace the AV-8Bs lost in 2012, but surely the Navy has a few F/A-18s that have been SLEPed to tide the Marines over....

[Bigpants]

Just a quick thanks for the response JF.

[ORAC]

I presume this is the "quick fix" to get the test aircraft flying again, not the longer term solution?

So, another couple of months delay in the program, presumably taking the planned carrier sea trails out of the plan till at least next year?

Pratt: F-35 Fix Could Begin Installation Before End of Year (http://www.defensenews.com/article/20140916/DEFREG02/309160025/Pratt-F-35-Fix-Could-Begin-Installation-Before-End-Year)

NATIONAL HARBOR, MD — Engine manufacturer Pratt & Whitney believes it could begin retrofit fixes by November for the engine issue that caused an F-35A to catch fire this summer.

“Probably in the November timeframe, with some anticipated success, we would begin the retrofit with emphasis on the SDD [system development and demonstration] jets,” Bennett Croswell, Pratt’s head of military engines, told reporters at the Air Force Association’s annual Air & Space conference.....

[tanimbar]

This story might make a few chuckle, especially John Farley.

While walking the hills I infrequently bump into an old RN articifer (b.1942). We chat, exchange views, knowledge - you get the picture. For some reason I described the problems with the F-35A engine, i.e. excessive blade rubbing leading to eventual fire. My friend smiled knowingly and his eyes sparkled. With some delight he then told me that in the mid-1960s he was aboard the RN aircraft carrier first tasked with trialling the new Buccaneer S.2 with its new Spey engines. (Note: I should have asked for more details of ship and date.)

He said that the Speys were failing at an alarming rate and that he and other articifers were working round the clock replacing them. Because the engines were 'sealed units' no-one on-board was allowed to strip the engines to find the cause (not that that would have helped operationally). This went on for days; good engines running low; tempers high between enginering and flying staff.

Eventually a senior RN engineer was flown aboard. He waited for a flight of Buccaneers to return. There were engine failure(s). Engineer proceeded to strip a Spey, something my articifer friend had never witnessed before - it made a great impression. Anyway, eventually the senior engineer reports to all the witnesses to his butchery that he has found the cause of the failures....

...... rotor blades failing due to excessive rubbing against the surrounding engine casing.

Of course, a solution was found and, as we all know, the Buccaneer S.2 and Spey went on to great acclaim.


regards, Tanimbar

Update courtesy of David Parry: the carrier was HMS Victorious, 1966.

[Willard Whyte]

So, knowing that such a thing was a problem 50 years ago, it still hapens now. O.K., different manufacturer, but still. Just a case of NIH Syndrome?

One wonders whether the F/A-18V(arious) had such problems, and how long they took to resolve. Same for the F-4, F-14, not to mention land-based fighter/attack aircraft of course.

[longer ron]

We are 50+ years down the road from Spey's etc...

Also aircraft like the Buccaneer or F18 do not have the weight problem of the F35 'B' !
Any added weight is a problem for any aircraft but it is a crucial area for the F35 B

Also - historically blade rubbing might be viewed as a problem during 'enthusiastic' handling - but unless I have misunderstood - the blade rubbing on the F35 happened whilst being flown fairly sedately !

[Engines]

Hempy (and others)

I've been taking a long break abroad with Mrs. Engines, so not so much posting recently.

I don't think I can add much to John Farley's responses, which cover all the angles as far as I can see.

The only thing I would add is that people should understand that the F135 development programme was required to 'push the envelope' to a very high degree in terms of thrust/weight ratio as well as src, and many other demanding performance targets to support all three variants. It's a very large diameter engine, and I'd think I'd be safe in assuming that this might have contributed to the rubbing between the rotors and the casing - it could be that P&W's models for this effect didn't hold up under all loading conditions. But that's pure speculation. In any case, it's a much tougher issue to prevent than with smaller engines.

It should also be appreciated that the entire propulsion system is a separate programme between the DoD and P&W, with the results being supplied to LM as Government Furnished Equipment (GFE). As a result, this problem is firmly in the DoD's court with P&W to solve.

Given all the above, I'm quite surprised that the programme has not had more engine issues to date. Almost all combat jet aircraft programmes I have looked at have had significant if not serious engine problems at one time or another. The UK have had some especially bad ones, as have the US. This one is serious, no doubt about that, but as JF so wisely says, this event is 'pure engineering gold'. More so as no-one got hurt during it. It will definitely help the engineers at P&W deliver the best possible product to the front line as soon as possible.

Hope this helps, best regards as ever to all those exceedingly clever propulsion engineers who have to cover the 'hard yards' for real

Engines

[Frostchamber]

Heartfelt thanks - and immense respect - to JF and Engines for your measured, reasoned and erudite contributions that act as such a welcome counterweight to all the armwaving.

[glad rag]

As a current UK taxpayer [ the ones who foot the bill :ouch:] I think I shall do all the arm-waving I bloody well want, Frostchamber...

[Engines]

Glad,

A slightly pedantic point on 'who is paying'.

On this engine issue, P&W are footing the bill. On the engine development, the UK's share of development costs is a fraction of what we would have paid RR to do the job. For what it's worth, I think the UK Government should have pressed the US Government much harder (and paid if necessary) to keep the F136 alternate engine option open. However, water under the bridge and all that.

Arm waving is, of course, a democratic right. Third Amendment and all that. Please arm wave without let or hindrance. As ever, all I'll try to do is provide information to help the discussion along.

Best Regards

Engines

[Frostchamber]

Absolutely. As regards the armwaving, all I was saying was how glad I am to have JF's and Engines' counterweight to it :)

[Fatnfast]

Engines, I have it on good authority from a RR engineer, that both RR & GE offered to carry on and fund the development themselves; but the powers that be ordered it be canned.:{

[glad rag]

Absolutely. As regards the armwaving, all I was saying was how glad I am to have JF's and Engines' counterweight to it :)

Thats good, you were starting to sound like Alex Salmond [and his ilk] there!

[Engines]

Fat,

It's true that the RR/GE team offered to continue F136 development at their own cost, but only up to a specified point. The F-35 programme and the DoD would have had to cover the full development costs as well as the costs of qualifying the F-35 with the F136.

As I've posted before, I had a brief but interesting 'ringside seat' on the alternate engine issue in the late 90s. There was a real tussle within the DoD between the engine technical experts, who were convinced that their funding and guidance was giving P&W the right solution, and the propulsion acquisition guys who were scarred veterans of the 'Engine Wars' of the 1970s and 80s, especially the PW100 saga. The JSFPO convened a special panel to review the situation, and at that time the alternate engine programme got a 'pass'.

Sadly, the UK MoD declined to positively endorse the F136, and left the issue to the USG. The result that was when the Obama administration came in and were looking for cost reductions to offset other areas of F-35 cost growth, the UK's late efforts to save the F136 were not viewed as credible.

Anyway, water under the bridge, it's the F135 and P&W to sort the issue out.

Hope this lot is of passing interest to someone,

Engines

[LowObservable]

Armwaving, n. - Arguments with which one disagrees, while being unwilling or unable to advance factual or logical grounds for such disagreement.

Engines - could you elaborate a bit on "pushing the envelope to a high degree in terms of TW"? Because the F135 weighs 6,500-some pounds and puts out 43,000 pounds, which translates to a nonstellar 6.6:1 (the F414/EJ200 are around 10 and the GE F110-GE-132 is about 8).

I've heard it suggested (recently from a source who really ought to know) that there are stealth and thermal management features in there, and the extended jetpipe, but (to paraphrase Elvis) that's still a hunka-hunka-burning-engine.

[Willard Whyte]

Perhaps the non-stellar T/W ratio will result in a far more reliable power plant?

Or, maybe not.

[LowObservable]

One would hope so, of course, but it's probably not the best time to advertise that to the program office or the operator.

[longer ron]

An engine which goes 'Bnag' may be viewed by some as engineering Gold LOL...
Personally I would describe it as being more like engineering Brown and as I posted earlier - any fix is likely to add weight to the engine - not a huge problem for most combat aircraft but for the Turkey 'B' it could well be a wee problem !!

Not sure if that counts as 'Armwaving' but to paraphrase a famous advert - ''there could be trouble ahead'' and one way or the other you can be sure that the taxpayer will pick up the tab as usual !

rgds LR

[Fatnfast]

Engines,

Thanks for putting more meat on the bones of that particular story.:D

[tdracer]

First, a disclaimer - new weapons programs generate critics, regardless of the merit of the program or how well it is executed. I distinctly recall massive criticisms of the M1 Abrams tank - it was too big and expensive, it was a gas hog, it's turbine powertrain was fragile and would never survive in combat, the high tech main gun would never work, tanks were obsolete, etc. Then it went into combat and totally kicked ass - arguably the best tank ever. Turned out the only thing the critics had right was the 'gas hog' part.
So, that the F-35 program has many critics is not meaningful by itself. But, I know quite a bit more about aircraft than I do tanks, and I have friends that worked on the Boeing JSF entry - people that told me what was wrong with the Lockheed JSF entry over 10 years ago. So I can more readily judge the validity of the F-35 critics, and quite frankly many of their complaints about the F-35 ring true to my ears.


EVERY new engine program will push the start of the art - if it doesn't there really isn't much reason to spend billions on the development. Different programs push different aspects - fuel burn or TSFC, weight, thrust to weight, noise, etc. But they all push the limit. Further, military engines tend to accept more risk and push a little harder than commercial engines (it's worth noting both the GEnx and Trent 1000 engines on the 787 and 747-8 have been surprisingly reliable at EIS - something that wasn't the norm on past new commercial engines). But there is another side to that - I've spent over 35 years dealing with engines from "the big three" - Pratt, Rolls, and GE/CFM. All three have various strengths and weaknesses - to the point that if you tell me the problem, I can generally - with close to 90% confidence, say which engine company it is. Example problems:


Compressor Stability
Inclement weather
Fan flutter
.
.
.
.
.
.
.
.


And the answers:
Compressor stability - Pratt
Inclement weather - GE/CFM
Fan Flutter - Rolls


As I noted in my earlier post 5159, tell me the problem is compressor blade rub/case distortion, and my answer would immediately be Pratt - they have a long history of that - and the other two don't. It's not that the F135 was beyond their models - it's that their models for case distortion simply are not as good as the other guys.


Oh, and don't fool yourself, Pratt may pay for the fix in the short term, but long term it's always going to come back to the taxpayer in the form of higher prices for future engines and spares. It always does :ugh:

[Engines]

LO,

I'll do my best, but I don't have the figures to 'elaborate'. I may be able to explain what information I have used to make the statements about T/W ratio.

The UK and US ASTOVL studies in the 80s generated a number of models and data around the driving technologies and capabilities needed for supersonic ASTOVL. Those were carried forward by the US in the late 80s and early 90s, and indicated that significant improvements in core engine performance were needed, in terms of specific thrust, sfc and also overall thrust to weight ratio. As I understood it, the studies showed that more thrust was needed from less engine volume and mass to make the STOVL sums work.

The DoD was also funding a major programme called Integrated High performance Turbine Engine Technology (IHPTET) (1987 to 2005), that involved all the key US manufacturers and was aimed at developing the key technology for the next generation of engines in a number of categories. F135 (and F136) both benefitted from this programme.

By the early to mid 90s, the DoD were convinced that the next generation of engines (with IHPTET technology) would be able to deliver the improved performance required to make the JSF work. Now, how this translated into actual figures for the F135, I can't comment. I would agree with you that this engine very probably has a lot of 'stuff' attached to it to deliver signature and other targets, but that can only be speculation. It's possible that your figures are 'apples and oranges', but I honestly don't know.

Longer - sorry, my bad, I should have been clearer. An engine mishap that doesn't totally destroy the engine, and doesn't cost a life is 'engineering gold', at least in my view. One that costs a life isn't.

Tdracer - thanks for an informative post. I heard similar concerns from the DoD engine guys in the 90s over P&W's record on military jet engines, and they were VERY keen to get the F136, along with it's UK developed LP compressor design, into service. However, the die is cast, and I agree that in the long term, the customer ALWAYS pays. That's a given for military engines whatever side of the pond you're on.

Best Regards as ever to those working the detail against the clock,

Engines

[effing Finn]

Engines,

Arm waving is, of course, a democratic right. Third Amendment and all that. Please arm wave without let or hindrance. As ever, all I'll try to do is provide information to help the discussion along.

The Third Amendment is quite affable, but in a Brit taxpayer's case one might go for the Magna Carta angle first.

Actually just chimed in to say (after being pointed on this forum and actually reading through as hefty as illuminating a chunk of the "Cats and flaps" thread, and some of this one too) your insight will continue to be appreciated.

One thing I didn't semi-immediately notice, anyone have recent figures of which country/service (for those of you with pilot wear to choose from) at the moment is getting how many of which type?

Loking at this from the angle that some type of F-35 might actually be the first/desired choice for lil' Finland's next jet. Unless Gripen NG really materializes then performs like a silent bat out of hell on cross-country skis, which isn't a proven sate of affairs yet. (Next jet TBD sometime between 2016-2020, in unknown numbers. Safe to assume that F-22 is either too costly or too unavailable.)

[kbrockman]

The problem is not about technical teething issues, it's all about the
money;

GAO Draft Slams F-35 On ?Unaffordable? Costs: $8.8B Over Legacy Fighters « Breaking Defense - Defense industry news, analysis and commentary (http://breakingdefense.com/2014/09/gao-draft-slams-f-35-on-unaffordable-costs-8-8b-over-legacy-fighters/)
WASHINGTON: The F-35′s long-term costs may “not be affordable” and appear to be substantially higher than those of the existing combat aircraft fleets that the Joint Strike Fighter will replace, the Government Acocuntability Office says in a draft report.

....
The estimated gap between the F-35 sustainment costs and those of the F/A-18, F-15, F-16 and the Harrier fleets as measured in 2010 is impressive, about $8.8 billion, an increase of 79 percent. That estimate comes from the Pentagon’s authoritative Cost Assessment and Program Evaluation (CAPE) office, the GAO draft report says. The draft says that costs for the legacy fleet were about $11 billion a year in 2010. Based on CAPE’s estimate, the F-35′s annual costs will be $19.9 billion in 2012 dollars.

one of the funnier quotes;

The GAO does say that the military “has begun some cost savings efforts and established sustainment affordability targets for the F-35 program, but DoD did not use the military service budgets to establish these targets,” so they “do not provide a clear benchmark…” As one example of that disconnect, the auditors say that the program “arbitrarily lowered” the estimate for F-35 fuel costs by 10 percent.

Now there's a neat accounting trick.

[Hempy]

Engines,

Many thanks for the reply, I hope you and Mrs Engines enjoyed the break.

I understand that the engineers involved are having issues, and I completely understand the terms of reference that they have been subjected to in regards to performance demands.

It just seems that there has been a serious case of over-promise and under-deliver going on here, regardless of the 'reasons'.

One would think, given the decades that we have been building jet engines for, that 'design issues' could be accounted for in a reasonable and rational way when forecasting future timelines.

Referencing past design 'teething problems' as an 'excuse' is simply saying 'we don't learn....'

It's just as well there isn't a serious shooting match looming on the horizon...


Marine Corps F-35B IOC shall be declared when the first operational squadron is equipped with 10-16 aircraft, and US Marines are trained, manned, and equipped to conduct CAS, Offensive and Defensive Counter Air, Air Interdiction, Assault Support Escort, and Armed Reconnaissance in concert with Marine Air Ground Task Force resources and capabilities. Based on the current F-35 JPO schedule, the F-35B will reach the IOC milestone between July 2015 (Objective) and December 2015 (Threshold). Should capability delivery experience changes or delays, this estimate will be revised appropriately.

[LowObservable]

The IHPTET T/W goal was 20:1, which is 2x better than we do today (F414/EJ200 are close) and 3x better than the F135.

I was pretty close to IHPTET at the time and it was recognized that it would, in the appropriate cycle, provide you with the dry thrust needed for non-afterburning VL (the use of A/B having been recognized as a nonstarter by then.)

The ATFE was always aimed at 10:1, but that didn't take a 2D nozzle into account, which is why the F119 is relatively heavy. If the F135 was a 10:1 engine it would weigh 4000-4300 lb (depending on whose thrust figures you believe) but it weighs 6500+ lb (says P&W). That's a lot for a length of straight jetpipe and some thermal-management kit.

[Engines]

Hempy,

Thanks for the kind wishes.

The challenge for designers and engineers is that the performance envelope is always being pushed. This is true for all combat aircraft systems, especially propulsion. The F135 is an extremely advanced engine, with a number of novel features. Many of these are firmly 'US eyes only', but my (slightly informed) guess is that it is pushing the boundaries in all areas.

When you do that, you run the risk of the unexpected. This appears to have happened here. It's not at all unusual for new engine programmes, and as I've posted before, the 135 appears to have delivered well to date.

I suppose that, as an engineer, I expect problems. I don't want them to happen, but they usually do.

LO, we could trade engine performance figures for some time, the only common factor being that neither of us has access to the actual data needed for a comparison. All I will say is that if the 135 had not delivered on its thrust/weight targets, the F-35B would not have passed the major review of a few years ago. What I can say is that when I left the programme some years ago, the engine was on target for weight, and was starting a further weight reduction plan that had been applied by the DoD as a 'stretch' target.

During the F-35B weight reduction plan, the propulsion system was required to achieve further reductions, one of the major changes arising from that was re-engineering the 3BSD from steel to titanium. RR's performance on this effort was described to me as 'absolutely stellar' by some hard bitten engineers at Fort Worth. Other areas of work on the propulsion system, led by talented young Brits, generated significant improvements in VL thrust efficiency.

My bottom line - I believe that the F135 driven propulsion system for the F-35B is meeting its weight and performance targets. Others may (and probably will) differ.

Hope this lot is of some interest,

Best regards as ever to those actually crunching the numbers,

Engines

[gr4techie]

M1 Abrams tank... Then it went into combat and totally kicked ass - arguably the best tank ever. Turned out the only thing the critics had right was the 'gas hog' part.

Iraqi Abrams losses revealed - IHS Jane's 360 (http://www.janes.com/article/39550/iraqi-abrams-losses-revealed)

[j58spike]

The IHPTET T/W goal was 20:1, which is 2x better than we do today (F414/EJ200 are close) and 3x better than the F135.

I was pretty close to IHPTET at the time and it was recognized that it would, in the appropriate cycle, provide you with the dry thrust needed for non-afterburning VL (the use of A/B having been recognized as a nonstarter by then.)

The ATFE was always aimed at 10:1, but that didn't take a 2D nozzle into account, which is why the F119 is relatively heavy. If the F135 was a 10:1 engine it would weigh 4000-4300 lb (depending on whose thrust figures you believe) but it weighs 6500+ lb (says P&W). That's a lot for a length of straight jetpipe and some thermal-management kit.


The pratt provided 6500+lb weight figure for the F135-PW-600 (the version for the F-35B) includes the lift fan, roll posts, driveshaft, and 3BSM.

The F135-PW-100 and F135-PW-400 don't have all that extra junk (they are comparable to traditional jet engines with some stealth radar/ir features added and in your words are the jet engine core with a "length of straight jetpipe and some thermal management kit"). The weight for the F135-PW-100 is around 3,750 lbs. This would put the thrust to weight ratio of the actual F135 engine at around 11.467.

If you are comparing a F135-PW-600 to a legacy engine it is an apples to oranges comparison because legacy engines don't have all the STOVL equipment.

[LowObservable]

Engines - I'm not arguing that the engine weight isn't on target; I'm saying that compared to other fighter engines, the CTOL/CV engine's T/W is low. I don't pretend to know why this is so.

J58spike - Your post is not accurate, I'm afraid. These weights have been confirmed by P&W. Many other figures float around on the Internet but they are fantasy.

http://www.f-16.net/forum/download/file.php?id=10587&t=1

[j58spike]

The picture you posted is referencing requirements, not the weight of the actual engine. That is why is states "not to exceed weight." (And those are older requirements btw, as the program has evolved they have rebalanced mass reqs. between different sub-systems).

Do you have a primary source that actually states what the weight is?

[LowObservable]

The weights were confirmed to me, via email, by a P&W official, in 12/10. Those more recent figures are 6444 lb for CTOL and 10342 lb for STOVL.

Now, please cite your own evidence for your figures, including historical cases where an engine was delivered at less than 60 per cent of its contracted NTE weight.

[Hempy]

Even with 'weight reduction programs' those figures are close enough to be at least ballpark.

3.5 tons of metal pushing out 17 tons of thrust on an MTOW 26 ton aircraft that just happens to have a wing area roughly half of other Gen 4 or 5 fighters.

This all reminds me of stories I read about the German Propaganda machine keeping civilian hopes alive during the dark days of 1944 with promises of magical 'Wünderwaffen' that were going to save them all.

I hope all the promises come true. I will truly admire the machine if they do.

[RAFEngO74to09]

On 20 Sep 14 I was able to get on the USS Nimitz during Fleet Week in San Diego. One of the sailors I spoke to said he was looking forward to the next task which was trials with an aircraft that had never been on a carrier before. Unless there is some new "black" aircraft, I assume that this will be the F-35C as per this earlier report:

Navy's F-35C Completes Landing Tests Ahead of October Sea Trials - USNI News (http://news.usni.org/2014/01/28/navys-f-35c-completes-landing-tests-ahead-october-sea-trials)

If correct, this would mean no slippage to the plan since Jan 2014.

[Turbine D]

Re:F-35C Carrier Trials

If correct, this would mean no slippage to the plan since Jan 2014.
I would rather doubt that, not much is flying and what is flying is limited because of the unresolved engine problem. Six more days left in September and without a release by the safety folks by September 30, everything starts slipping according to General Bogdan.

BTW, I wonder if there has been a solution to transporting spare engines to the carrier as they are too big and heavy for what was to be conventional transport.

[LowObservable]

There's still a chance of CV trials in Oct/Nov but the go/no-go decision point is imminent.

[ORAC]

BmIXJoLXBiY

[Typhoon93]

This is pretty confusing. Am I right in assuming that:

F-35A is conventional take-off and landing. I'm assuming that will be for the U.S Air Force.

F-35B is V/STOL which will be used by the US Marine Corps, RAF and FAA.

F-35C is conventional take-off and landing which will be modified for the US Navy's carriers, like the F/A-18.

The reason why I am asking is because it's bloody confusing!

How many other customers have invested in to this aircraft?

[typerated]

T93,


Please post some more of your thoughts.


It brings me great joy to read such genius.

[orca]

Whilst the jury is still out as to whether there is such a thing as a stupid question, it is true that you are able to make yourself look a little daft by asking something easily found out elsewhere.

Typhoon93,

You could (theoretically) try to modify a modern fighter to take a cat shot and arrested recovery but it would stand you into danger. Best to design it that way from the start.

But in answer to your question Canada, Australia, Italy, Norway, Denmark, The Netherlands and Turkey are A model partner nations. The UK and Italy are B model partner nations. The US services are as you assume. Israel and Japan are Foreign Military Sales customers. Three variants and nine partner nations, so actually less complex than a decent round.;)

[LowObservable]

Speaking of arrested recoveries, Norway is apparently paying an extra $246 million for a brake-parachute installation. The first sketches of this, many years ago, showed the chute deploying from a little pimple. Not so much any more, and what is that huge THING going to do to the RCS?

http://aviationweek.com/defense/norway-paves-way-f-35-acquisition

[APG63]

Typhoon93, what the hell are you talking about? You express amazing views here, but you appear to have zero grasp of what the subject of this thread is about. You are in danger of appearing to be a bit of a troll. Read up for a few months and come back when you understand at least the subject, even if you haven't even seen or understood the issues.

[Typhoon93]

APG, I wanted clarification on the aircraft types, more than anything. I'm definitely not a troll!

[APG63]

T93, you're very inconsistent in your posts. Here, try this, Lockheed Martin F-35 Lightning II - Wikipedia, the free encyclopedia (http://en.m.wikipedia.org/wiki/Lockheed_Martin_F-35_Lightning_II)

Or read the last two hundred and sixty something pages of thi thread. Actually, do read at least some of this thread and understand some of the issues before you start another hamster wheel here.

Generally I just read this thread.

[Tourist]

I've been trying to work out what the deal is with Typhoon.

He initially came on here in newbie happy mode saying hello. Then he scatter gunned every thread in sight, and recently he has started giving authoritative opinions cut pasted badly from others opinions yet now back to childlike questions.

I'm guessing about 12 yrs old?

[typerated]

Tourist,


Stop please.


He might stop posting - I (and I suspect a few others) would then miss out on a steady stream of comedy genius.

[typerated]

But on thread,


After fun with the Typhoon gun


What chance of the UK buying gun pods for Dave?

[mikip]

here we go another bit of useless trivia for the price of 1 F35B (£98.5 millionish) you could have bought 140 spitfire Mk 1's (£12,604 in 1938 = roughly (£0.7 million today) I know what I would rather have but there again I'm old and out of touch. On a more serious note it highlights the problem equipping the modern air force, capital vaule of the current miserably few assets is probably similar to that of the force in 1939

[Courtney Mil]

mikip, I know we've done this here before, but I don't believe your costing for the F-35B. Almost everyone here will give you a different figure and it's hard to tell which one is right. What I do know is that it's higher than most people think (or wish to believe). There's a lot of smoke and mirrors involved.

This might help explain - until it gets discredited by someone that doesn't want the cost to be too high.

https://medium.com/war-is-boring/how-much-does-an-f-35-actually-cost-21f95d239398

[mikip]

Ok I accept that my figure might have been low, it came from wikipedia so quite a lot a salt may be needed, if we take the figure of $251,000,000 quoted in the article you linked to = roughly £156,150,000 it just highlights the probelem of purchasing sufficient assets even more as for that you could buy 223 spitfires. I accept that it's all been done before and the figures for F35 are purely finger in the air jobbies but it's fun to speculate isn't it?

[henry_crun]

Watching the F-5B Youtube vid posted by ORAC above I noted that:

1. It didn't land vertically.

2. It landed horizontally wih the fan intake door still open.

Are there things yet to be sorted?

[163627]

MIKIP, re the "value" of the 1939 RAF to that of today try using the Mars Bar method of comparison; take the cost of a 1939 Mars Bar (first marketed in the UK 1932) and divide that cost into the cost of RAF at that date. Do the same with today's Mars Bar and the present RAF. Then see which gives you most bars! It may seem a little silly but economists use this method of historical comparison all the time and its surprisingly accurate! An alternative view-point could of course be that with economists thinking about chocolate its no wonder the world economy is in the state it is!!!!

[Maus92]

@henry

Yes, there are still details to be sorted. VLs need specially prepared landing surfaces to resist heat and velocity related damage, spalling etc. It's unlikely that Miramar has installed these yet - at least in airshow areas.

All F-35s (with a few exceptions) are still limited by restrictions put in place to avoid "blade rubbing," presumably until the root cause is officially identified, and I suppose a retrofit is designed, tested and installed. Perhaps a "break-in" routine could mitigate the situation in the interim.

Finally, the F-35B has modifications that need to be performed before IOC. Some of these involve door hinges and replacing/doubling structural frames that will take some time to retrofit.

[LowObservable]

Henry C - The public displays so far have included a lot of short/rolling vertical landings, because nobody wants to resurface the runway after the show. VLs so far have been confined to steel ship decks, AM-2 pads over concrete, and special VL pads made out of the kind of stuff you use to make pizza ovens.

F-35B acquisition costs can be found in US DoD budget:

https://www.bga-aeroweb.com/Defense/Budget-Data/FY2015/F-35B-STOVL-NAVY-PROC-FY2015.pdf

Operating costs as estimated in the US don't apply to the UK, because the Marines expect to use STOVL on only 10 per cent of sorties. The F-35A is estimated as 27 per cent more costly per flight hour than the heavily used and elderly F-16 force, and the B will be substantially higher because of the cycling of the lift fan and drive mechanism twice per STOVL mission.

[Engines]

Henry C,

Perhaps I can help out here a little on F-35B matters.

F-35B VLs require dedicated pads or steel decks. They can't do a VL onto asphalt, nor are they required to do so. (It was known at the start of the programme that, like a Harrier, hot exhaust ages will disrupt asphalt very quickly). The preferred landing option for restricted areas on land is an RVL (Rolling Vertical Landing), which is what the aircraft did in the video clip. (The runway at Miramar is very probably asphalt covered).

The lift fan door is open in this mode to allow the lift fan to operate - the door has two settings, one nearly vertical, used at lower speeds, and a lower setting (I think its around 30 degrees open) at higher speeds. You see both those settings used in the video, by the way. It's operating as designed.

Maus92 is absolutely right - the F-35Bs have a number of structural mods required in service. (By the way, so do the F-35A and the F-35C). The B also had an issue with lift fan door hinges, my sources tell me a fix is designed and being incorporated for these - not a huge job.

As I've posted before, the whole point of the F-35B is to operate from ships and short strips as required by the UK and the USMC. That powered lift capability comes at a cost, which LO is absolutely right to point out. But you can't get an F-16 to operate from a ship or a 1500 foot runway. Comparing aircraft that have totally different requirements can sometimes be slightly less useful than other more valid comparisons.

Just my view, there.

Best regards as ever to all those working hard towards F-35B IOC

Engines

[PhilipG]

Am I right in thinking that there has yet to be a definitive statement on what the cause of the engine fire was and hence it would seem that any required redesign of the engine has yet to start, implicitly delaying the USMC's desired IOC of May 2015?

Also is there any update on the software status, last I heard the US Army was looking at it, we in the UK need to have Software version 3F for our front-line planes not a pre technical refresh Version 2 or 3i of the software.

I am assuming that the planned carrier trials for the F35C have been delayed because of the engine problems, can anyone confirm?

[Willard Whyte]

(The runway at Miramar is very probably asphalt covered).

Concrete. (http://www.airnav.com/airport/KNKX)

I think they use a lot of it stateside due to high ambient temperatures.

[LowObservable]

No worries, the exhaust will :mad: up standard Mil-Spec runway concrete as well. On the bright side, the RAF won't need a replacement for JP233.

[NITRO104]

VLs need specially prepared landing surfaces to resist heat and velocity related damage, spalling etc. It's unlikely that Miramar has installed these yet - at least in airshow areas.
Sry to barge in, been outta loop for a while.
So, 35B needs dedicated surfaces after all?

[GreenKnight121]

Only if you are going to perform repeated vertical landings on the same spot.

If you are doing short-rolling landings, or only an occasional VL on different spots, then normal Mil-Spec runway concrete is sufficient.

Heck, with a short-rolling landing/take-off even asphalt works, as long as you don't keep using the same patch over & over.


The special pads are for repeated regular vertical landings.

[Whitewhale83]

As the B will be spending most of it's life doing completely conventional take off's and landings I don't think anywhere in the UK would need any special surfaces. The carriers are obviously getting thermal coatings but will be mostly SRVL which will spread the load out.

[orca]

Why will they be mostly SRVL?

The SRVL gives you no bolter option, a portion of the approach with no overshoot option, a second landing that's a VL in any case, a divergent reaction to failure or poor technique (as opposed to a wire which centres you up) and a total reliance on the brakes.

[NITRO104]

GreenKnight121, thx.
AFAIR, there have been various statements regarding this issue, so this settles them now.

On another note; did Harrier need special surface for continuous VTOL ops.?

[orca]

No, but it did damage the VSTOL surfaces and the Harrier max ramp TO weight is very similar to the F-35B empty weight.

[WhiteOvies]

F-35B only needs SRVL when heavily loaded in extreme climatic conditions that severely degrade hover performance (the USMC aren't worried about it.) It's a UK specific requirement put in based on conditions our Harriers and carriers experienced in certain middle eastern areas. The F-35B has plenty of hover performance in most conditions so I would suggest that most landings will be VL.
I'm sure SRVL will be practiced and simmed as required, it has a lot of benefits when a VL with both weapons bays full may be marginal.