F-35D, other Lighting II versions

Hi All,

I have read in several places that the USAF had discuses the posibility of a forth version called F-35D:

Here is the reference:

http://savage-comedy.com/_F-35_Joint_Strike_Fighter
One option discussed and discarded was a fourth, F-35D, variant that would have a different propulsion system to increase emphasis on STOL capability over that of VTOL, a larger wing to allow more fuel, an interior cannon (as opposed to the USMC external gun pod), and changes to in-flight refueling (sacrificing compatibility with Air Force KC-135 Stratotankers, which only use the flying boom in-flight refueling system, but not the KC-10 Extender).



http://www.aerospaceweb.org/aircraft/fighter/f35/
F-35D (?) Proposed model for the USAF similar to the F-35B but emphasizing short-takeoff and landing (STOL) rather than STOVL operations, would feature a revised propulsion arrangement based on the General Electric F136 engine and use the larger wing of the F-35C to increase fuel capacity and range, also to be equipped with an internal cannon and an Air Force-style refueling probe; USAF expressed interest in over 200 of this variant for close air support but it was quickly cancelled due to increased development costs and reduced commonality with the F-35B

.......

I have used the parts from all tree versions of the F-35 to make the “D” model on Photoshop
Here are the features of the design so far.
- Fuselage from F-35B
- Wings from F-35C, however folding mechanism was removed to reduce weight and increase wing caring capacity (not sure about this change)
- Roll control ducts are removed (not visible but obviou as we have a new wing and the aircraft will not have to hover)

While I was preparing that post I realized that I have to do the following changes in my next post as well .
- Air Force-style refueling probe added from F-35A
- Internal gun from F-35A

Should I keep the fins are from the F-35A?( I am not sure if I should add bigger fins from the “C” model)

Any other suggestions?

lantinian

Here how all this started....

First I made this picture of a supercruising F-35 version with a simple delta wing. I knew I had to get rid of some stuf to get the speed capability.

Then I put some more thought behind the wing idea and the result was a low cost medium bomber with limited supercruice capability. The definite F-35E (F-35XL like) is posted on this discution topic:
http://www.secretprojects.co.uk/forum/index.php/topic,1248.msg15595.html#msg15595

Then I made the "D" model

I have not put "copyright lantinian" anythere, cause I have used some existing images with minor modifications i its not right. If anyone thinks my logic in not correct, please let me know.

Enjoy!

lantinian

Well, I guess this will be a one man discusion topic :

Here is the F-35D with internal gun and Air Force-style refueling probe, fresh from photoshop.

Notice that the refueling receptacle takes the space of the top mounted airintake of the engine. Since it is used only in hover and the "D" model is STOL, the doors are no longer necessary.

Because of the new rules for attachments, I have resized the original images of the A,B and C models to max of 600 pixels after I posted them yesterday. Anyone interested to get the big versions can visit this link:

http://images.google.com/imgres?imgurl=http://www.jsf.mil/images/f35/f35_variant_stovl.jpg&imgrefurl=http://www.jsf.mil/f35/f35_variants.htm&h=1024&w=1280&sz=246&hl=en&start=8&um=1&tbnid=XtGJpDhCZL2IiM:&tbnh=120&tbnw=150&prev=/images%3Fq%3Df-35%26imgsz%3Dxxlarge%26ndsp%3D18%26svnum%3D10%26um%3D1%26hl%3Den%26safe%3Doff%26client%3Dopera%26rls%3Den%26sa%3DN

regards,
lantinian

Hmm, I DID not make this picture.

However it is somewhat relevant to this discussion and I would like to post it anyway.

Whoever made it thinks that 2D vectoring vectoring nozzles are still the most attractive way to vector trust. Well, I don't
Second, with regards to the anonymous author, the weapons arrangements he has devised for the lightning are all wrong. This is due to lack of space and the incorrect size of the weapons. Also attention was not paid to separation safety.

Anyway, I leave any further comment to you guys.

regards,
lantinian

Now we are two ;D
Well this is a fantastic and interesting job. I like the delta variant, maybe it could be a low-cost competitor to the FB-22A (FB-35A ?) (after all the F-16XL was a competitor to the F-15E, even if basic F-15sand F-16s are not in the same league)

Ah, I hate to burst a bubble, lantinian, but the F-35A and F-35C have the same wing tankage, the difference in wing area is in non-fuel sections (C has larger leading edge and trailing edge sections and has greater span). I can see a variant of the F-35A with the refueling probe used by the F-35B/C as we're pretty much leaving that bay untouched on the F-35A for common systems routings (at least as much as possible) across all three variants (I work as a design engineer on the F-35 forward fuselage, I do have some familiarity with it).

I am honoured to have a LM engineer with a comment on my F-35 related opinions. If what you say is the case then I stand corrected.

However the common since I used is that the the "C" model wings are not only of higher aspect but also have longer chord. As the wing root is typically the thickest part of the wing it should have more fuel indeed. But here is another quote from the web re the F-35D:

http://rides.webshots.com/photo/2033167010090154019bSQphz
The most obvious of these modifications is a 35% larger wing permitting a higher fuel capacity and providing greater wing area for improved lift at low speeds.

However the site of LM you work for says:
http://www.lockheedmartin.com/wms/findPage.do?dsp=fec&ci=15146&rsbci=11173&fti=0&ti=0&sc=400

"A larger wingspan provides increased range"
But not increased fuel? I guess then range is increased troughs greater wing efficiency, not additional fuel.

But the "C" model does carry more fuel in the end. Where? If it has a stronger structure to support carrier landings, should not that lower its fuel capacity?

regards,
lantinian

Well, I work on the forward fuselage and not the wing (deos gratia) so I can't comment completely. While the "C" wing is definitely stouter, I rather suspect the difference in fuel tankage is comparatively minimal and there's fuselage tankage, too, so total fuel capacity being the same isn't a problem. The larger chord and extended span come from dry areas of the wing, not "wet" ones. All three versions of the wing have very similar structure and area assembled, equipped, and finished on the same tooling. One of the F-35's virtues is that while there are three versions, the same production tooling works for all three.

Probably a silly question, but nevertheless : Is, or was there a proposal for a twin seat
version ? Ok, nowadays it seems to be generally excepted, that there's no need for
a trainer version. And in the US forces, the F-35 will fill hte "low" end of the high-low
mix, missions for which two crew members are essential, will be fulfilled by other types.
But the F-35 is expected to become THE US aviation export article of the next decades
and I guess, that other airforces will use it for some other missions, too, eg. SEAD, electronic
warfare, or maybe in the future, lead aircraft for UCAV. And even with more efficient,
fully automated systems, I'm pretty sure, that the need for a twin seat version will
arise, if not from the US forces, but from the many, many export customers.
Can't remember to have seen such a version still yet.

I'm not sure if this was ever considered as a real option ... but anyway it's looking fine !

Deino

Jemiba said:

Probably a silly question, but nevertheless : Is, or was there a proposal for a twin seat
version ? Ok, nowadays it seems to be generally excepted, that there's no need for
a trainer version. And in the US forces, the F-35 will fill hte "low" end of the high-low
mix, missions for which two crew members are essential, will be fulfilled by other types.
But the F-35 is expected to become THE US aviation export article of the next decades
and I guess, that other airforces will use it for some other missions, too, eg. SEAD, electronic
warfare, or maybe in the future, lead aircraft for UCAV. And even with more efficient,
fully automated systems, I'm pretty sure, that the need for a twin seat version will
arise, if not from the US forces, but from the many, many export customers.
Can't remember to have seen such a version still yet.

Click to expand...

I'm pretty certain that such is at least being studied for future use. Beyond that I can't comment since it doesn't show up in my area until it's a going deal.

I know LM have considered an Unmanned or Optionally Manned (Mannable) version.

To keep the cost down the only visible new item might be a invisible canopy covering a large fuel tank in the place of the pilot. Part of this place could also be reserved for extra electronics necessary to make this aircraft automated or contriled from distance. Perhaps a satellite dish like on the Global Hawk.

This is of course all educated guesses on my part. The concept image is also based on the navy aircraft. The only reason for that is the greater range, loiter time and stealth that this version has. In addition both the USAF and the USN have requirements for the sort of aircraft. Hence the X-45 and X-47 aircraft demonstrators/

I have also added the USAF air refueling receptacle in addition to the boom type used by the navy.

Since, this version will not come out at least 10 years form now and is likely to benefit from better FCS I have considered removing the vertical tails as well. Please let me know is you feels it will be an overall better guess for the future

Another thing I do not stand behind is the fuel content, which I only believe should be higher than in the CV, but I how no idea by how.

regards,
lantinian

P.S. I plan a do a 2 seater called F-35F. Anyone cares to make a suggestion on which version or mix of versions shout it be based?
P.S.S. I have updated the F-35D picture ( I have forgotten to delete the air refueling boom perceptible)

A F-35"E" (E=Energy) ;D
Edit:
"F-35E" as "F-35XL" used before, so now F-35"L" (L=LASER).

Instead of a direct lift fan, a high power generator is installed to power a directed-energy weapon system.
This weapon system could be fitted as an external pod like as the gun pod in the F-35B and F-35C . I doubt, such a system would fit internally instead of the gun as on the F-35A. 8)

Directed-energy weapons

Directed-energy weapons may be installed in conventional takeoff F-35 Lightning II's, whose lack of a direct lift fan frees up about 100 ft³ (2.8 m³) of space and whose engine provides more than 27,000 hp (20 MW) for electrical power.[18] Some concepts, including solid state lasers and high-power microwave beams, may be nearing operational status.[19]

Click to expand...

Source:

lantinian said:

[...]
http://savage-comedy.com/_F-35_Joint_Strike_Fighter
[...]

Click to expand...

I doubt, such a system would fit internally instead of the gun as on the F-35A.

Click to expand...

You mean, fit like this ?

links to picture:
http://www.abovetopsecret.com/forum/thread35304/pg1
http://www.analysiscenter.northropgrumman.com/files/Operational_Implications_of_Laser_Weapons.pdf


More Info:
http://www.newscientist.com/article.ns?id=dn2585
http://www.afa.org/magazine/June2006/0606laser.asp

And a 3 view comming shortly...

regards,
laninian

Behold....The 100kW laser equipped F-35BL (L for Laser).

Will it happen? Definitely. LM are surely working on the project now as the Northrop-Gruiman analysis in the link above suggests.

The picture is based on the NG-model and illustrates the most simple way of integrating it into a production F-35. In this case it is the "B" model of the USMC.
Changes include:
- removal of all STOVL equipment except for the shaft driving the lift fan.
- removal of top air intakes for the main engine. or it least sealing them into unmovable position.
- cutaway pieces from the lift fan covers now form the covers of the two laser extending from the top and bottom. The Lift fan doors are still used for maintenance and removal of the laser system

The laser system has two beam projectors with sphere shaped for low drag in any direction. The two spheres extend only when shooting as the EOTS does the targeting for them. The spheres can rotate full 360 is necessary, however rear targeting may be more problematics as the F-35 has less tracking sensors facing its rear.

The aircraft powers the laser system via the main engine. It provides power trough greater fuel consumption. In a sense the laser ammunition is the fuel itself. As the F-35B has the lowest fuel capacity of all 3 versions. the "BL" model may not be the most practical adaptation especially for the Navy and the Air Force which traditionally need more range.

Anyway the authors preferred concept is coming shortly... : In the mean time, please let me know what you think!

regards,
lantinian

We all see that the F-35 program experiences delays and constantly rising development costs. Some have suggested that the F-35 may turn out to cost more than half the F-22 price, thus killing its main justification to exist (A least for the "A" mode)

While, LM is probably full of concepts for adapting the F-35 for other roles (UCAV, Laser Platform, Electronic Warfare) it is questionable when will the budged allow for such ideas to be realised.

A few years back the NAVY made suggestion to the MARINES to drop the STOVL version in favour of the CV variant. USAF had also considered buying the NAVY version instead of the CLOT model. If for some reason the JSF program experiences budget shortage and the 3 services cannot get their aircraft in time, it is possible they might reconsider their requirements and LM should be able to respond.

It is interesting that the more the R&D spending of an aircraft increases the more the flyway cost doesn't mater. The current "C" models excels in range, while the "B" model struggles to meet that goal as well as the vertical landing part.


If the NAVY decides to sacrifice a bit of range and most importantly the MARINES drop the STOVL requirement in favour of STOL, more range, payload and stealth, then it may be possible for a single airframe to do all the jobs. If the services agree on a really common version before R&D is finished, it may turn out to be cheaper then any of the original 3 versions.

The proposed F-35D holds the key to me. It has STOL capabilities, it has good range, stealth and can be easily converted to carry a laser or have an unmanned cockpit.

The image below is a variation of the F-35D. has the following features:
- Everything except the cockpit area is from the Carrier model
- The Cockpit area is from the STOVL model
- from the "A" model is the structure supporting the internal gun or Small fuel tank in its place
- a USAF refueling boom is added in addition to the drogue chute to all variants.

Each service configuration can be achieved trough optionally installed components:
* Lift fan + drive shaft + swiveling nozzle + small fuel tank/internal gun = STOL variant
* Large Fuel tank + internal gun/internal gun = Carrier capable standart variant
* Laser System + drive shaft + Small fuel tank = Carrier capable Laser variant
* UCAV cockpit + large fuel tank + Small fuel tank = medium range UCAV

All variants will be able to hold 2000lb bombs and land on a aicraft carrier.

The F-35D picture in the above posts is similar to the F-18L concept in the early 80s with the Navy wing without the wingfold. All structure specific to the NAVY are removed or replaced with lighter ones. The plane had great potentail but no commercial success.

The F-35L picture below is an attempt to combine what is best in all JSF versions, while keeping the cost down trough no pre-installed structures unique to each variants and mass production. The optional components will be like special internal stores, adding capabilities the wing stations do not support. Export versions can also be configured uniquely.

No one can tell how much UCAVs will you need in 10-20 years or how Laser Weapon development will influence the battlefield, or even how much will the US rely on carriers as friendly nations number shrink and so do land bases. And post service entry configurable JSF version can addapt on a maintenance depot level, not on a drawing board level which is the case with the current concept.

regards,
lantinian

An updated picture of the basic F-35 variants was posted recently by flightglobal on this Link:
http://www.flightglobal.com/assets/getAsset.aspx?ItemID=13300

I have attached a small version of it.

Through more detail examination (assuming the drawing are correct) there are some apparent differences in all 3 versions of the F-35. These are probably as a result of the weight reduction efforts done on the STOVL model and spread across the other versions. There seams to be some performance optimisations as well.

Here is what I noticed:

- the front edges of the canopy are different
- vertical fins have greater backward inclination
- internal gun opening is smaller
- some features on top of the fuselage are missing at all or from the "A" and "B" version only
- Wing flaps are slightly longer but much narrower
- horizontal tails have greater area but lower aspect ratio
- rudder area is increased
- wing area of the carrier version is increase slightly
- the engine nozzle access panel on "A" and "C" models is no longer visible
- CV tailhook fairing is somewhat wider

I also read in flightglobal that the last lift fan door configuration will not fly until the 5Th STOVL aircraft and the first flight is yet to happen.

So with minor external changes still happening, my previous post makes even more sense. I am also thinking to redo the other F-35 versions to this standart.

What do you think?

regards,
lantinian

Well, as far as I know, the basic doors, fan, et al. will be the same on the first F-35B as on the rest. Now, the fifth "B" constructed will be the first one with all the goodies in place from the beginning (assuming none of our vendors muck up the works).

As for the laser-armed version, while the EOTS may not cover the rear hemisphere, there are other systems, albeit not as precise ones, that do. There's a lot shoehorned into that airframe.

Regarding F/B-35. What range would it possibly have?

Regarding F/B-35. What range would it possibly have?

Click to expand...

Are you referring to the picture of what I thought it may look like F-35E ? If yes, I believe can best the FB-22 as far as range goes.

If not, which version are you referring to?

I would also like to ask if anybody thought of a cost effective way to enable to F-35 to serve as a candidate for the NLRS, knowing it only needs more range weapons (laser among them) and better RCS?

lantinian

lantinian said:

Regarding F/B-35. What range would it possibly have?

Click to expand...

Are you referring to the picture of what I thought it may look like F-35E ? If yes, I believe can best the FB-22 as far as range goes.

If not, which version are you referring to?

I would also like to ask if anybody thought of a cost effective way to enable to F-35 to serve as a candidate for the NLRS, knowing it only needs more range weapons (laser among them) and better RCS?

lantinian

Click to expand...

Your version

The next question would be, if the VSTOL engine concept on the F-35B could be used on other aircraft projects?
Just imagine, two engines are powering one or two lift-fans. The space between the engines could be used for fuel and a weapon/cargo bay.

FB-35, MC-35, HV-35, etc.... : 8)

When is read HV-35, I remember the movie "Executive Decision", (1996 staring Halle Berry, Kurt Russell, and Steven Seagal) were the the fictitious F-117X Remora was the real star!!!
The F-117X was a larger F-117 with a Cargo bay and a docking system, so fresh crew members could exchange on to space aircraft's or bombers. The engines had also afterburner... :

A stealthy VSTOL and CSAR aircraft for the SOF!!!

A stealthy VSTOL and CSAR aircraft for the SOF!!!

Click to expand...

I believe that project was developed under the codename, "Senior Citizen." Although the engineering paper I have shows that separate lift engines were better for that role than shaft driven fans.

It seems to me that mounting the laser's optics just above and behind the cockpit canopy would be potentially rather dangerous and it's more likely that a single unit would be housed in a streamlined ventral fairing. Of course, I might be wrong!

Anybody have an idea as to the current limit of watts/mm^2 they can pipe through optical fibers? It would be nice if they could just keep the laser "engine" in the most convenient space and pipe the light to emitters located on various areas of the aircraft. Of course you still have to direct the beam and compensate for atmospheric distortion so maybe it wouldn't be practical.

I suspect the beam director would be ventrally mounted, similar to how the EOTS is mounted. Mind you, this is no more than informed speculation on my part but it makes sense given the overall aircraft configuration and that the laser assembly itself would be installed in place of the F-35B's lift fan and driven by the same driveshaft.

It would be nice if they could just keep the laser "engine" in the most convenient space and pipe the light to emitters located on various areas of the aircraft.

Click to expand...

As far as I understand, right now everyone is working hard to get the laser system efficient enough to produce a 100kW solid state laser mounted on a small aircraft. Efficiency in space and laser power are #1 and #1 design drivers. What you consider "nice" is still in the Sci-fi world for now. If the laser has to "travel" from the place being produced to the place being "emitted" it will no doubly loose energy and the "connection" between the two will no doubt produce cooling problem which could impact the fire rate.

Anyway, I believe that for the moment designing a very powerfull laser that can shoot 60 times a minute is better than having several smaller ones that cannot produce the necessary damage.

Besides, to keep cost down, any modification will have to happen with minimum or no change to the aircraft. The only way this could happen is if the whole system is mounted as a single unit on the place of the lift fan. If the emitters would have to be placed in different locations, then it may be necessary to redesign the structure that houses the laser "path"

That is of course just my opinion.

lantinian

According to info in Aviation Week, what elmayerle said is what they are looking at, although they said it could have a "turret head," for lack of a better term, on both top and bottom for missle defense.

lantinian said:

Behold....The 100kW laser equipped F-35BL (L for Laser).

Will it happen? Definitely. LM are surely working on the project now as the Northrop-Gruiman analysis in the link above suggests.

The picture is based on the NG-model and illustrates the most simple way of integrating it into a production F-35. In this case it is the "B" model of the USMC.
Changes include:
- removal of all STOVL equipment except for the shaft driving the lift fan.
- removal of top air intakes for the main engine. or it least sealing them into unmovable position.
- cutaway pieces from the lift fan covers now form the covers of the two laser extending from the top and bottom. The Lift fan doors are still used for maintenance and removal of the laser system

The laser system has two beam projectors with sphere shaped for low drag in any direction. The two spheres extend only when shooting as the EOTS does the targeting for them. The spheres can rotate full 360 is necessary, however rear targeting may be more problematics as the F-35 has less tracking sensors facing its rear.

The aircraft powers the laser system via the main engine. It provides power trough greater fuel consumption. In a sense the laser ammunition is the fuel itself. As the F-35B has the lowest fuel capacity of all 3 versions. the "BL" model may not be the most practical adaptation especially for the Navy and the Air Force which traditionally need more range.

Anyway the authors preferred concept is coming shortly... : In the mean time, please let me know what you think!

regards,
lantinian

Click to expand...

this idea of putting the laser instead of the fan is particularly clever!!!

The top/bottom turrets arrangement is similar to something that showed up on the proposed LM stealthy gunship...it allows 360 degrees coverage above and below the horizontal plane, something useful if your aircraft is flying in a banked turn. (AC-130s are vulnerable because they have fixed armament on the port side. That forces them to fly in predictable orbits).
Furthermore, you could also engage aerial targets flying at or above your flight level with the top turret, soomething denied with a single ventral turret.
IMHO, the retractable turrets would not carry their "lids" on top of their heads...if you tried rotating the turret in elevation, you would produce A LOT of aerodynamic loads. more likely, you would have simple hinged fuselage doors, not unlike what covers the lift fan. Just a guess on my part...

Why guess if Lantinian had already posted LM vision of the laser-equipped F-35 in this thread?

In regards to the whether the pop up laser should carry its own door or whether the door should have a separate hinge....

Yes, indeed the way I pictured it not only may have aerodynamic complication but also will prevent the laser from firing directly up or down.

However I suspect that side opening door may also limit the side firing angle in adition to presenting a much larger RCS to the enemy. This will also likely to be a heavier solution too.

I guess the LM engineers will have to figure out the solution that is optimal from all point of view.

One things for certain. The laser will have a cover if
it is a pop up instalation.

BTW, F-35 turret images origin is 2005 Northrop Grumman 'Operational Implications of Laser Weapons' paper
http://www.analysiscenter.northropgrumman.com/files/Operational_Implications_of_Laser_Weapons.pdf

Found this one awhile back. It is certainly a rather interesting concept.

Speaking of the F-35, when introduced into service it will only be able to carry four air-to-air missiles internally. Yet it has been confirmed that the ability to carry six missiles is possible and will be introduced at a later date. The same article also mentioned the possibility of eight missiles.

Now do any of you guys have a concept of how six or eight air-to-air missiles would fit into the two weapons bays of the F-35? I imagine eight would require a design with folding fins or a dedicated storage and ejector system.

I believe this concept was posted here previously

Those ideas are interesting but require a wingless missile. Second, I doubt the USAF will consider adopting any weapon system that requires a sequential missile release.
The YF-23 had one and the Air Force did not like it.

But Yes, with the right modifications and the F-35 bay would certainly be able to fit between 6 and 8 AAMs total.

I believe six missiles could be fitted without too much modification. I imagine eight is where you would need a design with folding fins design unless you had some sort of complex ejector system. I have read of studies regarding a folding fin AMRAAM but have not found any diagrams or concepts of this.

Do you guys have any information about the system tested on the YF-23?

Do you guys have any information about the system tested on the YF-23?

Click to expand...

People here rarely mention something casually unless it was discussed in another tread. It a good thing to search before you ask.

http://www.secretprojects.co.uk/forum/index.php/topic,1092.msg14140.html#msg14140

Lampshade111 said:

I believe six missiles could be fitted without too much modification. I imagine eight is where you would need a design with folding fins design unless you had some sort of complex ejector system. I have read of studies regarding a folding fin AMRAAM but have not found any diagrams or concepts of this.

Do you guys have any information about the system tested on the YF-23?

Click to expand...

The internal volume of the F-35's bay is reportedly larger than that of the F-22. In its current layout it can only carry four AIM-120s because each of the two bays only has two attachment/ejection points for weapons. The Project Office has been investigating using the large weapon bay volume to carry additional air-to-air weapons internally The thought is the F-35A could carry eight AIM-120s missiles internally. There is reportedly a low key project to develop and test this. If it works, it might start showing up on planes ordered in the middle of the next decade.

One modification USAF wanted on the launcher arm of the F-23 had it gone into production was that they wanted some form of dual launch capability, rightly being concerned that a single failure could keep it from launching all of its internal AIM-120s.

I can understand why there's a need for separate STOVL version, but is there any reason why the Air Force can't use the F-35C? I'd think the weight of the internal gun would offset the extra weight of the heavier landing gear, and there's no harm in having more range and better low speed handling, is there? (And no, pride is not good enough a reason. Not with this much money involved.)