That Baltimore Sun article has a curious analysis. I would have said the Boeing approach was the most conservative, since diverting the fan thrust of a linear engine is conceptually similar to the Harrier. McDonnell Douglas's initial approach, with the gas-driven fan, was the most radical, since I don't know of anything like that ever being proposed before, while their final lift+lift/cruise proposal was almost as conservative as Boeing's in that such a configuration has been flown in service by the Russians, proposed many times in the past and therefore extensively studied and well understood. Lockheed Martin's shaft-driven fan was somewhere in the middle (literally and conceptually...
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I'm going to keep trying to find articles from way back when, because they are certainly interesting. You are right though. Bevilaqua points out that the Boeing approach to STOVL Direct lift, got them selected basically because they pointed out the Harrier is the most successful (at the time only, I'm including the V-22 now) STOVL aircraft and it used direct lift. Very funny anecdote here actually:
https://youtu.be/u-cfy-k_8ew?t=47m22s McAir basically gambled that the STOVL design wouldn't be weighed as heavily as it was, even though I think they were warned the government would not accept it.
Let me put it another way: The F-35A is land-based CTOL, the F-35B is STOVL and the F-35C is carrier-based CTOL, but they're all based on the same airframe. To what extent is each type compromised in it's role by the need to build the other types from the same basic airframe, and to what extent are the capabilities of the whole programme compromised by the need to repalce so many different types?
In other words, would the F-35 be a better F-16/F-18 replacement if it wasn't also trying to be an AV-8B replacement and an A-10 replacement all in the same basic airframe, and vice-versa?
I think this thread is going to explore that. The JSF and compromised seem to go hand and hand but is there anything to it? and can we look at other programs as examples? First stand by for a "Stream of consciousnesses" post that hopefully doesn't get too muddled. I am looking at this first from an engineering perspective, I will save the political decisions and needs for another time.
An extreme example: is the F-22 compromised by its inability to carry paratroops? We would probably say no since that was not one of its goals, and early on we knew that this would not be a cargo aircraft, so the inability to carry cargo does not compromise its mission. So how "compromised" something is IMHO has a lot to do with the goals/requirements of the weapon systems. TFX struggle because the mission sets simply differed too much.
When the original F/A-18 came out it was widely panned because it couldn't carry the bomb load the distance that the A-7 it was replacing in the attack role could, Nor could it fly as fast as the F-4 it was replacing in the fighter role. It was critisized for being a jack of all trades master of none. It was slower, and couldn't carry the bombs as far. It was a "mix" a multirole aircraft that replaced multiple types (including the A-6 with the Marine Corps). How did it work out? I would say it was a success. If the mission was not attack/fighter though, it the mission was "high altitude recon" merged with "low level attack" it could not be done. TFX was penetrating striker, merged with interceptor, Which then changed with "need for dogfighter" too. I had also heard an anecdotal that said McNamara was allergic to spending any kind of money on it, including cases where a little more cash would have made it more feasible, but he constantly jumped on the cheap solution only and it simply could not be overcome, along with lessons learned in vietnam (it simply couldn't be a missile plunking fleet defender now)
The A-10 replaced the A-7/F-100 (which was being supplanted by A-7), A-37, and A-1 skyraider. So the A-10 replaced multiple types, its original 1966 CAS mission was changed to prep for killing tanks in europe and it was built around a huge anti armor gun. It was deliberately made simple, with many basic things (for example a Inertial navigation system) left of, thus it was primitive than what it replaced in some cases (especially the A-7) I'll let former A-37, A-7 and F-16 pilot say it better:
The Sluf armament system used a very primitive computer and the inertial platform data and basic ballistics data for bombs to provide extremely accurate bombs. Oh yeah, a real HUD from Marconi. The Hog would only have had to used a simple range radar to enable a computer to provide the bomb impact dot on the HUD, but not requiring a cosmic radar like the Sluf had ( we had terrain following and terrain avoidance and two ground map modes and a beacon mode and bomb delivery mode that provided the computer with slant range).
It is no wonder why we Sluf folks laughed and laughed when we saw what USAF was selling to Congress just to get the plane funded and stop the Army Cheyenne. Of course, the plane was being developed to fight in 'nam, and that war was ending. The big cannon was about the only thing that we did not already have, plus the stupid weather requirements that only a helicopter could meet....
- We A-37 and A-7D folks understood the new plane would basically be a jet-powered A-1, and would supplement the A-7D. We knew the A-37 would never see combat again after 'nam except for a COIN scenario. The emphasis was upon CAS and CSAR and such, with a bit of BAI thrown in.
Thinking and actual force build up at the time was the A-7D replacing the F-100 and supplementing the F-4 for interdiction. And the SLUF was very good at CAS. The only two planes with in-country FAC ratings of 15 meter CEP were the SLUF and Dragonfly. We have the 7th AF Corona Harvest documents to back up my assertion.
- Somewhere along the way the Cheyenne popped up and USAF was afraid of losing the CAS mission. Then there was the Fulda Gap. And if I was writing a book, I would call it "How a valley in Europe designed a (not so) modern warplane".
The gun came along after the initial RFI and maybe even RFP. And let's face it, the rounds were lots cheaper than Mavericks. Even so, the A-10 was a decent shooter once we got the IIR missile, as tgt acquisition was a bear with the EO version even with scene mag. The Pave Penny sensor also let the grunts designate the tanks, so acquisition was easier ( but nearly as good as slaving the seeker with fairly cheap avionics)
- We attack folks wanted both the A-X and the A-7D. The LWF program was just gaining traction, but we all thot it would mainly complement the Eagle and have a limited A2G capability to supplement the F-4, A-7 and A-X. F-100 wings would be replaced by A-X or A-7D. Maybe an F-4 wing would go, and all the Thud outfits were moving to Guard and Reserve.
Congress wanted as cheap an airplane as they could get, and USAF sold the A-X as not needing computers or high-tech stuff to do the job. My editorial back in 1974 made this clear and I was harshly reprimanded for saying so. Interestingly, my CO and wing DO saw the letter before I mailed it and had no qualms.
As a result, we had a significant period of reduced A2G capability in the late 70's and early 80's until the Viper came onboard in numbers, and we should all thank God the plane was such a great design.
- And then there was the significant drawdown after 'nam. We were equipping Guard units with the A-7D as early as 1973, and we stopped the A-7D fleet at three active duty wings. The stateside units and those in USAFE remained pretty much in place, so it was all those bases in 'nam and Thailand that bit the bullet. For example, the F-100 wing out of Tuy Hoa, I think, was moved to England AFB and then converted to the A-7D. Myrtle Beach was same. And Davis-Montham. Cannon absorbed 'vaarks...
...So we see what we needed for the Vietnam scenario and realize that the Hun, Thud and Double Ugly ain't gonna hack it for CAS and BAI. Talking about 1969 or 1970. The A-1 and the A-37 did super work in that environment from mid 60's to early 70's.
To get the A-10 we had to "dis" the A-7 and admit the Hun and 'vaark and Thud were not well-suited for CAS. We also had to move from piston motors to jets, so the A-1 was off the table. The A-37 was off the table because it was a superb COIN plane but could not meet the new requirements that included tank-busting and large payload.
The A-7D was so gold-plated that the Viper did not come close until the late 80's. It ( the Viper) had great A2A capability and a decent ground map radar and such. Sweet.
But USAF CAS mafia had sold Congress the AX, and contrary to some here it was not a single mission jet. It would replace the F-100, the F-111, the F-105, the A-1, the A-37 and the A-7D. So we Sluf folks asked, "what about interdiction"? Also asked about precision weapon system and a hundred knots extra speed. Oh yeah, what about a computed weapon delivery system and both an INS and a Doppler nav system and a ground map radar and an autopilot and a projected map display and.... No matter. They said the A-10 would be cheap, simple, and we could have many of them
Is the A-10 compromised? Is its world famous gun a part of what compromised it from being more versatile, or faster? etc? would it have been better served with a radar like the A-7?
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Are all CVN aircraft inherently compromised by heavy structure needed to land on ship with cats and traps? A Super Hornet weighs as much as an F-15 for example.
You can look at Rafale, which replaces no less than 6 aircraft types with the French Air Force. including two carrier types, thus requiring Carrier capability in the original design from the outset. Is the Rafale thus compromised?
But its part of a larger trend of multi-role aircraft taking over not just one type, but many.
So from engineering stand point, is the F-35 compromised to the point it can't do its mission? I would say no. but lets look deeper, how did STOVL requirements shape the F-35? how did it shape other JSF competitors? STOVL knocked out the McD design we know that. X-35, F-35 has the following considerations:
Forward hinging Canopy, Dual Intakes like the F-22-- rather than say the F-16, Wingspan dictated by the requirement to fit 6 on the back of an L-class ship. Weight constraints, though I would argue that is not a bad thing-- the SWAT effort made lighter F-35As by 3,000 lbs and had helpful savings on the F-35C as well. However it did drive up the cost, and delayed the program by 18 months:
http://www.airspacemag.com/military-aviation/weight-watchers-13117183/?no-istThe original manufacturing plan saved money, but not weight.
I think the aircraft being a LO shape had more impact than STOVL in terms of aerodynamics. That just my opinion.
The goal with ASTOVL and the USMC, was making a hovering F-18. when they were merged into CALF with the USAF the USMC basically deferred to the USAF so long as it hovered, and the USMC and USAF goals were very aligned. Both the USMC and USAF were fine for example with a 1,000 lb bomb load. the USAF was looking for a multi role F-16 replacement, the USMC multi role F-18 replacement with the ability to do STOVL. both favored single engine, both favored lighter as opposed to more advanced hi-end design etc. BF-1 just did its 1,000th VL, so I would say the propulsion system is damned good, and presuming the propulsion system is good I think its actually trickier in this case to meet the USN goals, the F-35C is the most "different" of all the variants I believe.
The next post can be about the politics, but to keep it simple, I would say that there was absolutely no way the USMC/RN could have ever been able to independently procure an advanced STOVL airplane by themselves, and even under the large JSF umbrella it was the version that most people suggested ending, most often including the RN being forced by politicos to briefly go to the C, before going back to the B. So I don't think it could have ever happened if it wasn't merged with other aircraft, but having said that the STOVL version of JSF benefits massively from the other variants in terms of advanced capability. There is simply no way the USMC or RN were ever going to get a jet (especially STOVL) that advanced all by themselves. Whats funny is there seems to be a much bigger market for the STOVL variant (turkey just announced its buying F-35Bs) than there ever was the F-35C.
So I would say that
1. There is a historical precedent set for replacing multiple types with a single type with success all over the globe
2. I would say that the missions of the JSF across the services and partner nations are aligned and that the main differences with the JSF variants are how they take off and land