CSBA Analyst Calls For F-35C Redesign

[usnvo]

The F-35C as it stands probably has more range (and far, far less drag) than a similarly loaded F-14D, or any F-18 variant (for an air to air mission). All it may need is a bit more power. There is no need to mess up a fine design.

I always laugh. If a 670nm combat radius is short ranged, what is long ranged? If you really wanted to make the F-35C a better fleet defense aircraft, how about a pair of 5000lb EFTs, certify the AIM-120 for external carriage, and povide a six shot internal AIM-120D capability. That would cost virtually nothing, give you something like 27klbs of fuel for greater loiter time, 10 AIM-120Ds and 2 AIM-9Xs, and not change the aircraft at all.

Or, my personal favorite, make a KF-35C to extend the range organically. A F-35C with the internal bomb bays removed and replaced with more fuel tanks, the centerline gun pod converted to a refueling pod, and a 5000lb EFT on the inboard stations and a 2500lb EFT on the outer stations and you have an aircraft with something like 36klbs of fuel. Should easily give you well over 15klbs at 500nm and be stealthy to boot. And it could still be a second day of the war bomb truck using the exterior stations.

And use up airframe life, like Super Hornets?

Not same situation.
- A notional KF-35C would be a dedicated airframe, like the KA-6D. So all it would do is the tanking mission. So you are not using up airframe life, you are using the aircraft in its intended role.
- Without F-18A-Ds in the airwing, and with Magic Carpet and Delta Flight Path, the need for fuel goes way down.
- Additionally, if you only use the outboard stations for maximum strike tanking, as well as minimizing fuel before landing, you won't stress the airframe as bad. For that matter you could probably meet all the recovery tanking requirements without EFTs at all. The SH Blk I airframe abuse is largely self-inflicted and much of it can or already has been eliminated with changes to how they are operated.

The MQ-25 is

[steve2267]

But the modifications go well beyond just up-rating the engine. They're talking about stretching the fuselage to carry more fuel, etc.. To me, this is a tacit admission that the F-35 (C, anyway) isn't as capable in the air to air arena as we've been led to believe. For if that really were the case, why modify it at all?

The F-35C was designed to meet the requirements laid down by the US Navy. Those requirements were for a VLO strike fighter, with a secondary air-to-air role. By all accounts it has met all it's KPP's (or at least the important ones.) It did this despite being "handicapped" by the OML of an Air Force fighter, and the length of a STOVL Marine jet that could not exceed a certain length lest it not fit below decks on certain ships. (It is possible the length limitation came from the Brits, but I am unsure -- or another class of Landing Helicopter Dock ships.) To be able to create three variants that have so much in common is impressive to say the least. I think it is the first time in history it has been accomplished so successfully. But that commonlity also imposed compromise on each of the three variants.

The F-35 meets and exceeds the requirements established by the customer. Why is this so hard to understand? Why is everyone in a tizzy? Go argue with the people that established the requirements.

To "say the F-35C is not as capable in the air-to-air mission as we've been led to believe" is just silly. To say that the F-35C could be more effective in the air, is akin to claiming the F-18A/C was not as effective in the air, so we need a "derivative" -- the Super Duper Hornet. I believe it was Quicksilver that recently pointed out the Super Duper is really an entirely new aircraft, and has very very little in common with the original Bug.

To say you have requirements for a fleet air defense, penetrating escort fighter is one thing. It is still another to suggest using the F-35C as a basis for such a design. And to do so may, very probably does, have a lot of merit. But to claim the F-35C doesn't meet the requirements for this new fleet air defense, penetrating escort fighter so we need to cut the F-35C buy in half to fix this shortcoming is stupidity to the nth order. The F-35C was never designed to meet those requirements.

"Oh, this aircraft doesn't meet these requirements that we never set for it. Therefore we should cut it's buy in half." No, you should be fired from whatever position you hold.

[steve2267]

Sure, it's a good thing. A VERY good thing. But the modifications go well beyond just up-rating the engine. They're talking about stretching the fuselage to carry more fuel, etc.. To me, this is a tacit admission that the F-35 (C, anyway) isn't as capable in the air to air arena as we've been led to believe. For if that really were the case, why modify it at all?

Stop, backup... Mixel first you state "to me", then in the next sentence it is suddenly "we've been led."

Who is we?

But perhaps you should just start with you. HOW is some political hack out in left field claiming that we should cut F-35C productiotn in half to fund the development of a new aircraft using the F-35C as a starting point... how is that a tacit admission? What is it admitting, to you?

Secondly, how have you been led to believe the F-35C is not "as capable in the air to air arena?" What program requirements is the F-35C not meeting that bears directly on it's failure in the "air to air arena?"

[element1loop]

"Oh, this aircraft doesn't meet these requirements that we never set for it. Therefore we should cut it's buy in half." No, you should be fired from whatever position you hold.

Initial design requirements may be static, but operating needs are not, they evolve, and do so very rapidly in a conflict. Hence why as quicksilver points out, this is what occurs to all US fighters. Increased flexibility overhead is what allows rapid adaptations to changed tactics or circumstances, and associated pronounced aircraft evolution, which was and still is so evident in all of the teen jets which is what has kept them on top. And they also ALL had new variants and redesigns, so quit the puritanical BS.

PS: It's you that's in a 'tizzy', not everyone else, if you want to suppress and discourage discussions by report writers or commenters you can have people taken out the back and shot, that shuts discussion down nicely.

[spazsinbad]

'StevieStevieStevie' perhaps one source said 'elevators' [quote from above]

" 'steve2267' said: ... the length of a STOVL Marine jet that could not exceed a certain length lest it not fit below decks on certain ships. (It is possible the length limitation came from the Brits, but I am unsure -- or another class of Landing Helicopter Dock ships.)…"

The CVF hangars and lifts are HUGE - TRUMP HHUUGGE! however a 'more credible source'? says:

The Influence of Ship Configuration on the Design of the Joint Strike Fighter
26 Feb 2002 Eric S. Ryberg

“...Unlike the CV variant, the JSF STOVL variant did not have a spot factor requirement levied upon it. Instead, the ORD specified a spotting requirement in operational terms. The USMC operators required that it be possible to park a total of six STOVL variants aft of the island on an LHA or LHD, such that none fouls the landing area and that any one of them can be moved without first moving any other. This requirement constrains the STOVL variant's wingspan to be no more than 35 ft.

OTHER GEOMETRIC CONSTRAINTS
Aside from the amount of flight deck space needed to accommodate an aircraft, there are several additional constraints that affect its geometry. Aircraft are stored in hangar bays with constrained overhead clearances. The ceiling height must allow the conduct of all maintenance and support actions, including such tasks as the removal and replacement of the canopy and ejection seat. Additionally, compatibility with deck elevators MAY constrain an aircraft's length, width, or both. Safe launch and recovery operations require sufficient separation from any deck obstacle, a criterion that often dictates the shape of an aircraft and the location of its wing pylons. Table 2 summarizes for each pertinent ship class the constraints imposed by the elevators and hangar dimensions.

IMPACTS OF GEOMETRIC CONSTRAINTS
While all of these dimensional constraints have been considered in the design of the JSF family, only in isolated cases has a ship constraint dictated the size of the airplane. The basic size of the variants is as large as can be supported by the allowable STOVL performance level attainable with the government-furnished engine and the contractor-determined STOVL lift mechanisms. For the sake of commonality, the other two variants are of the same basic size as the STOVL variant, with differences incorporated where necessary to meet the unique requirements of each service customer. In general, this size airplane is easily accommodated aboard the CVN-68 class, since the size of the CV variant approximates that of aircraft currently deployed. In designing the STOVL variant for operations aboard LHD class, it too, is of a size that readily fits within existing spaces, despite it being considerably larger than the AV-8B it will replace. However, basing the STOVL variant on LHA and CVS classes would require some modification to the aircraft to ensure complete size compatibility with all constraints (e. g., flight deck elevators). Since JSF will be based on these older ship types for a small fraction of the aircraft's overall service life, requirements officers and acquisition officials have been careful not to compromise aircraft performance over a 40 year span, in exchange for full compatibility with ships that will be out of service within five years of the aircraft's introduction to the Fleet...."

Source: http://www.dtic.mil/dtic/tr/fulltext/u2/a399988.pdf (1Mb)

[steve2267]

Initial design requirements may be static, but operating needs are not, they evolve, and do so very rapidly in a conflict. Hence why as quicksilver points out, this is what occurs to all US fighters. Increased flexibility overhead is what allows rapid adaptations to changed tactics or circumstances, and associated pronounced aircraft evolution, which was and still is so evident in all of the teen jets which is what has kept them on top. And they also ALL had new variants and redesigns, so quit the puritanical BS.

Your paragraph reads like a bunch of gobbleygook. Do you write it in this manner to affect an air of sophistication?

PS: It's you that's in a 'tizzy', not everyone else, if you want to suppress and discourage discussions by report writers or commenters you can have people taken out the back and shot, that shuts discussion down nicely.

I am a bit confused. It would seem that you ascribe to me the intent to murder people as a way to shut down discussion? Is this true? Are you accusing me of murderous intent?

You ran your mouth once before and accused me of stating one thing, when the forum clearly proved your statements and claims were wrong. I let it slide. You issued a rather embarrrassing mea culpa.

Are you trying for two?

This discussion boils down to a rather simple premise. Buyer sets requirements. Seller wins a competition and creates a product to meet said requirements. Buyer tests product and verifies product meets requirements.

Some nimrod comes along and says, "product doesn't meet requirements that were never required; let's cancel half the contract of the competition that they seller competed for."

Internet loses its mind at evil seller for not producing a product that doesn't meet requirements that were never stated.

[steve2267]

Spaz, you continue to amaze me. Pulling one great reference after another out from the ether. I recall that reference at least once before. But me thinks you had once before also posted a reference that had included purty pictures of flight decks on some ships? It seems to me there was at least one class of ship that had imposed a length limit on the F-35B because the elevator was not at the edge of the deck, so the tail couldn't hang out over da water.

In any case, my memory whispers to me that a previous discussion had concluded (or proven?) that the length limit on the F-35 was due to the STOVL requirement onboard some ships. And I thought it was the golden oldie Invincible-class that may have imposed those limits back in the late '90s, early '00s? But I could very well be wrong.

Bottom line... a length was chosen to meet requirements, and a requirement for maximum commonality dictated that all three aircraft be of the same length.

[element1loop]

Internet loses its mind at evil seller for not producing a product that doesn't meet requirements that were never stated.

What does this have to do with it? Leave it out.

The report argues that capability can be improved with a minimal modification or 'redesign'. As Mars pointed out this is likely angling toward an F-35D to meet F/A-XX REQUIREMENTS - whatever those turn out to be. Procurement plans evolve, deal with it. Disruption to acquisition or USN capability growth from inserting F-35D into production, half way through the C build, would probably be nil as capability growth would occur faster, sooner and cheaper, and with much lower risks than a separate F/A-XX development, while maintaining commonality with many parts and systems.

And such an added capability F-35-derived USN jet would appeal to several foreign F-35 operators, while an all-new USN F/A type is unlikely to.

[spazsinbad]

Without quoting all the above STEVEN post - I'll answer: Perhaps the graphic as you imagine it (I'm having trouble doing the same) was of an OLD LHA which was and is NOT in consideration as per my lengthy quote from the 2002 design peepls.

And yet said 'my quote' is clear about USMC length requirement for park aft of the island - how can that be any clearer? Again it is clear although early on the CVS was considered (along with old LHAs) it became clear that (given the now old time frame for use) that IF the F-35B could be operated from these OLD SHIPs then as quoted:

"... requirements officers and acquisition officials have been careful not to compromise aircraft performance over a 40 year span, in exchange for full compatibility with ships that will be out of service within five years of the aircraft's introduction to the Fleet...."

Sure that is a funny perhaps polite way to say 'these old ships aren't relevant' nor have they been, considering the delays.

[madrat]

Some arguments in this forum become circular. Spaz has the patience of Job to correct the same thing so many times.

[charlielima223]

Sorry guys... I just couldn't help myself


On a more serious note to the discussion I don't believe a "redesign" of the F-35C would do any real good except waste time and money. Yes future upgrades to the engine from AETP will improve range but it sounds like what they want is still going to be beyond what improvements the AETP will provide. What are they going to do? Create a larger version of the F-35C and call it the F-35D Super Lightning ala Hornet and Super Hornet? When the Tomcat was phased out in favor of the Super Bug, it was criticized for not having the legs of the Tomcat. If they want dramatically improved range and kinematic performance they're going to have to come up with a clean sheet design (dust off the NATF and bring up to modern standards). At any rate I think the USN is better off waiting for the F/A-XX

[steve2267]

On a more serious note to the discussion I don't believe a "redesign" of the F-35C would do any real good except waste time and money. Yes future upgrades to the engine from AETP will improve range but it sounds like what they want is still going to be beyond what improvements the AETP will provide. What are they going to do? Create a larger version of the F-35C and call it the F-35D Super Lightning ala Hornet and Super Hornet? When the Tomcat was phased out in favor of the Super Bug, it was criticized for not having the legs of the Tomcat. If they want dramatically improved range and kinematic performance they're going to have to come up with a clean sheet design (dust off the NATF and bring up to modern standards). At any rate I think the USN is better off waiting for the F/A-XX

I keep coming back to requirements.

What are the requirements for this F/A-XX? Have they even been defined yet? If not, it's a bit premature to be annointing a redesigned F-35C as the answer to undefined requirements.

So, just throw a bunch of money @ LM to "redesign" the F-35C, give it a stretch to hold more gas etc, cancel half the F-35C order and guarantee LM at least the same number of F-35D's as the cancelled number? Boing isn't going to squawk, file protests etc?

The US Navy has probably studied to death the number of F-35C's they require to fulfill their strike mission going forward. So those numbers were wrong and can be lopped in half? If not, how does Mr. Clark propose to meet the remaining strike requirement?

I can hear the shrieking now when the re-designed F-35D still can't supercruise because it got bigger & heavier to meet the 1000nm range requirement despite the extra engine thrust and is only a 6g airframe (or 5g), has a top speed of 1.5 Mach, but it can go out and back 1000nm @ 0.7Mach (!) with six AIM-120s. Oh, and it can't fit 2000lb bombs anymore. Maybe not even 1000lb bombs anymore.

And once the requirements are defined, it would be better to let contractors decide how best to meet them. It may be that LM could best meet those with an F-35C as a baseline and merely redesign it. Or not. Price & schedule requirements could factor in making it much more favorable to a LM F-35C redesign, as opposed to a Boing clean sheet.

Without requirements for this proposed F/A-XX defined, one would be pissing into the wind trying to mandate or even suggest changes.

[spazsinbad]

To help design an F-35C Derivative RYBERG gives some clues, whilst other references exist PDF below is text readable:

The Influence of Ship Configuration on the Design of the Joint Strike Fighter
Mr. Eric S. Ryberg 26-27 Feb 2002 COMPLETEpp15.pdf

download/file.php?id=19105 (PDF 1.1Mb 15 pages) [I forget where GIF BELOW is from]

A GAO Oldie: Navy’s Participation in Air Force’s Advanced Tactical Fighter Program March 1990 [excerpt below]
http://archive.gao.gov/t2pbat11/141083.pdf (2.1Mb)

Navy’s Participa­tion in Air Force’s Advanced Tactical Fighter Program
March 1990 GAO Report

"...Chapter 3 Basing and Mission Differences Affect Aircraft Design
Carrier Suitability
A key factor contributing to the design differences between the ATF and NATF is their different basing requirements. The ATF is designed to operate from land bases, whereas the NATF must operate from the pitching and rolling deck of an aircraft carrier at sea. To be suitable for carrier operations, the NATF must have, among other things, a stronger structure than the ATF to withstand carrier launches and recoveries; excellent lowspeed flying qualities tailored to carrier approaches and landings; and size, weight, configuration, and environmental compatibility with carrier operations.

Carrier Launch and Recovery
Carrier launch and recovery requires that an aircraft be equipped with a strong landing gear, an arresting tail hook, and a reinforced structure to withstand the high stress of catapult takeoffs and arrested landings. The acceleration, deceleration, and impact forces encountered by carrier-based aircraft are substantially greater than those experienced by land-based aircraft. For example, because land-based aircraft do not use catapults for takeoffs, they are not equipped with a nose landing gear suitable for catapulting or subjected to the substantial acceleration forces experienced during catapult takeoffs. Similarly, land-based aircraft do not routinely make arrested landings. Therefore, they are not equipped with a fully capable tail hook or normally subjected to the deceleration forces of arrested landings. The deceleration force experienced in arrested carrier landings is 24 times greater than that experienced by land-based aircraft, and the vertical impact force is over 3 times the level encountered by land-based aircraft. Accordingly, a land-based aircraft’s landing gear, wings, and fuselage must be strengthened with additional materials and/or redesigned structure to enable the aircraft to withstand the stress of catapult launches and arrested landings. Air Force and Navy program officials estimate that, to accommodate these and the other Navy requirements, the empty weight* [*Empty weight includes the weight of an aircraft’s structure, engines, hydraulic and electrical systems, and avionics. It does not include such items as fuel and armament.] of the NATF will have to be about 4,000 pounds heavier than the ATF.

Low-Speed Flying Qualities
To ensure a safe carrier approach and landing, the NATF must be capable of a lower landing speed and more precise flight control during landings than required for the ATF. The low approach speed is necessary to stay within the structural load limits of the arresting gear aboard both the aircraft and the carrier. If approach speeds are too high, damage or failure of the aircraft’s or carrier’s arresting equipment is a risk. In addition, a carrier-based aircraft’s design must provide unusually good aerodynamic performance at these low speeds for the precise flight control needed during carrier approach and landing.

Size, Weight, and Configuration Compatibility
Although carrier-based aircraft tend to have heavier structures to withstand catapult launches and arrested landings, they must not exceed certain size and weight limits imposed by carrier operations. The physical constraints associated with handling an aircraft above and below decks on an aircraft carrier pose strict limits on an aircraft’s size, weight, and configuration that are not normally imposed on land-based aircraft. The need to park and maneuver a large number of aircraft while avoiding obstructions, not only limits the aircraft’s length and width but also necessitates folding the aircraft’s wings. Similarly, aircraft weight is limited by the capacity of the carrier’s elevators, catapults, and arresting equipment. For example, the carriers from which the NATF will operate have an elevator load capacity of 130,000 pounds and dimensions of 70 feet by 52 feet. Because the Navy has a design goal of lifting two NATFS on an elevator simultaneously, the Navy has limited the NATF’S size with wings folded to basically that of the F-14 and has limited its takeoff gross weight goal to 65,000 pounds. The NATF must also be configured to accommodate carrier use and safe Carrier approaches and landings. The need for stability while maneuvering an aircraft on a pitching, rolling deck to prevent tipping to the side or back constrains landing gear placement. Further, main landing gear placement is also limited to allow for adequate wheel clearance from the edge of the carrier deck during catapult launch.

The NATF must provide the pilot with adequate visibility in addition to low-speed flying qualities to make a safe carrier approach and landing. Steep approach angles, required for carrier landings, demand that the aircraft’s cockpit and front fuselage design provide the pilot with an unobstructed view of the carrier deck and stern. This degree of over-the-nose visibility is unnecessary for a land-based aircraft. Consequently, the ATF cockpit, canopy, and front fuselage structure will likely be redesigned to provide the NATF pilot with an increased forward field of view....”

Source: http://archive.gao.gov/t2pbat11/141083.pdf (2.1Mb)

[madrat]

Wouldn't taking an F-35C as the base predetermine the winner of the design previous to any competition? Sounds like a silly beginning to failure by design.

[Corsair1963]

Honestly, perplexing idea as the F-35C has little real threat for the foreseeable future. Unless some believe the J-20, J-31, or Su-57 are substantially more capable. Yet, few with any real knowledge of the subject matter believe that....


In addition a number of upgrades will be available to the F-35 Series in the coming years. Including improved Engines and even better Avionics and Weapons. So, no reason to believe it won't be able to maintain it's current level of superiority over it competitors for sometime to come...


In short I see no reason for a major redesign to the F-35C. Other than the usual upgrades over it's life to keep it competitive.