A-7F in the 60's - a supersonic Corsair II

Archibald

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As said in the title. The A-7F was a terrific bomb truck but 1985 was way too late.
Now back to 1963 and VAL.
Whatif the A-7 had stuck with the Crusader reheat and supersonic speed ? not the J57 of course but an afterburning TF-41, very much the F-4K engine into the A-7 airframe.
Some developments
- same USN USAF procurement as per OTL
A-7 A/B/D/E
- In Vietnam its supersonic speed help replacing the F-105s at far lower cost than Phantom and F-111s
- since OTL A7F was born out of the Whartog being too slow, then ITTL 1972 the A-10 is stillborn and 700 more A-7s are build for CAS.
- Vought now has a multirole supersonic successor to the Crusader and this may impact the short ranged Hornet down the line...
- naval variant can provide air defence from Essex carriers like Oriskany replacing the old Crusaders
- in 1970 Vought scrap the V-1000 and pitch a multirole A-7 against the F-5E for IFA. While the Tiger II win, performance wise the A-7 attracts a lot of interest.
 

Archibald

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Folks, I've just checked the 1962 tri-service designations and bar F-4 F-5 and F-8 most of the others are old types, even bogus. Never realized that the F-7 was the convair Sea Dart, although it stopped flying in 1957, 5 years before.
Might be fun to rebrand the A-7 Corsair II F-7 or F/A-7, Hornet style of course (the irony !)
 

thefrecklepuny

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As said in the title. The A-7F was a terrific bomb truck but 1985 was way too late.
Now back to 1963 and VAL.
Whatif the A-7 had stuck with the Crusader reheat and supersonic speed ? not the J57 of course but an afterburning TF-41, very much the F-4K engine into the A-7 airframe.
Some developments
- same USN USAF procurement as per OTL
A-7 A/B/D/E
- In Vietnam its supersonic speed help replacing the F-105s at far lower cost than Phantom and F-111s
- since OTL A7F was born out of the Whartog being too slow, then ITTL 1972 the A-10 is stillborn and 700 more A-7s are build for CAS.
- Vought now has a multirole supersonic successor to the Crusader and this may impact the short ranged Hornet down the line...
- naval variant can provide air defence from Essex carriers like Oriskany replacing the old Crusaders
- in 1970 Vought scrap the V-1000 and pitch a multirole A-7 against the F-5E for IFA. While the Tiger II win, performance wise the A-7 attracts a lot of interest.

A bit like this:
 

isayyo2

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in 1970 Vought scrap the V-1000 and pitch a multirole A-7 against the F-5E for IFA. While the Tiger II win, performance wise the A-7 attracts a lot of interest.
The A-7F would be a modification of an in production design, unlike the V-1000/F-8 which I'd say is a major plus. An after-burning version of the TF41 would put out something around 23 to 26,000 lb.f of thrust? With the LERX and new flaps, low speed handling and landing performance should have been enhanced. Visibility for air to air combat would be equal to the F-8 and subpar against anything with a bubble canopy, though a VTAS helmet could even the odds?

Cost is still your biggest issue, though its capabilities are well beyond the F-5E. If you could get a demonstrator flying before 1972 or earlier, LTV should be able to win a few orders and lobby Congress to purchase more as well. Maybe get the Shah to fund it?
 

Pioneer

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In which case why not consider the Vought V-456 Attack Crusader as the basis of the design, as it's already based on the supersonic design, as opposed to turning the subsonic A-7 design into a supersonic aircraft.....

Regards
Pioneer
 

Archibald

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In which case why not consider the Vought V-456 Attack Crusader as the basis of the design, as it's already based on the supersonic design, as opposed to turning the subsonic A-7 design into a supersonic aircraft.....

Regards
Pioneer

Never heard about this one, which year ? if 1964 and beyond, A-7 is already in the place... but I surely love the Crusader.
 

Pioneer

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In which case why not consider the Vought V-456 Attack Crusader as the basis of the design, as it's already based on the supersonic design, as opposed to turning the subsonic A-7 design into a supersonic aircraft.....

Regards
Pioneer

Never heard about this one, which year ? if 1964 and beyond, A-7 is already in the place... but I surely love the Crusader.
Archibald, nor had I heard of the Vought V-456 Attack Crusader until I purchased the incredibly informative book Vought F-8 Crusader: Development of the Navy's first supersonic jet fighter by William D. Spidle, Specialty Press, Forest Lake, MN (2017), as emphasised by this wind tunnel model from the book:

P.S. as to the designs time frame, the V-456 was started in 1962.

Hope this gives food forthought.

Regards
Pioneer
 

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isayyo2

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Perhaps the A-7D could be ordered as the supersonic variant? For whatever reason the Air Force demands supersonic performance to replace the F-105 and F-100 thinking they’d get more F-4s or F-111s, but congress forces the A-7 as a jobs program and/or lobbying?
 

bobtdwarf

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In which case why not consider the Vought V-456 Attack Crusader as the basis of the design, as it's already based on the supersonic design, as opposed to turning the subsonic A-7 design into a supersonic aircraft.....

Regards
Pioneer

Never heard about this one, which year ? if 1964 and beyond, A-7 is already in the place... but I surely love the Crusader.
Archibald, nor had I heard of the Vought V-456 Attack Crusader until I purchased the incredibly informative book Vought F-8 Crusader: Development of the Navy's first supersonic jet fighter by William D. Spidle, Specialty Press, Forest Lake, MN (2017), as emphasised by this wind tunnel model from the book:

P.S. as to the designs time frame, the V-456 was started in 1962.

Hope this gives food forthought.

Regards
Pioneer
the attack crusader would also carry a LOT of sidewinders...that would not suck
 

F-14D

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One of the reasons USAF adopted (and significantly improved) the A-7 was that they were in the middle of Vietnam and didn't have the time to develop their own plane (which would take longer, cost more and wouldn't be much better anyway) .

Without going into a lot of detail here, the attack Crusader would have been even less of interest to the USAF than the A-7F was. There's been discussion of the A-7F elsewhere on this site as part of the CAS/BAI initiative (also as a way to get rid of the A-10). BTW, afterburnng TF41 was looked at for A-7F, but F100 and F110 had avantage of already ordered for US use. USAF's position can be summarized in one sentence: "We will consider any aircraft for the job impartially as long as it's the F-16".

I'm including two pix of one of the two demonstrators showing how the A-7F looked during tests at Edwards, and how she looked in 2013.
 

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F-14D

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In which case why not consider the Vought V-456 Attack Crusader as the basis of the design, as it's already based on the supersonic design, as opposed to turning the subsonic A-7 design into a supersonic aircraft.....

Regards
Pioneer
You could modify existing A-7Ds and Es into A-7Fs, whereas Attack Crusader would take longer and cost a lot more.
 

F-14D

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Perhaps the A-7D could be ordered as the supersonic variant? For whatever reason the Air Force demands supersonic performance to replace the F-105 and F-100 thinking they’d get more F-4s or F-111s, but congress forces the A-7 as a jobs program and/or lobbying?
USAF had run a series of studies for an aircraft to fulfill the CAS\BAI role (and also as a way to get rid of the A-10), but rejected the results when the F-16 didn't come out on top. Congress stepped in when they saw how cheap the A-7F would be and ordered USAF to test a demonstrator. But, they forgot to direct USAF to do anything with the results. So USAF tested, and then said, "We did what you said. Now can we have more F-16s please"?

Yes, I know that years ago I said I'd write a detailed story about the A-7F design
 
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F-14D

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By the way, A-7F concept was a modification of the A-7X concept proposed to the Navy in the previous decade which was rejected because it threatened the development of the Hornet, a program wildly popular with Congress.
 

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Archibald

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Glas to have you onboard that thread @F-14D

There were so many missed opportunities with an afterburning A-7D/E, right from 1965. TF41, F401, F110, whatever the engine. And I'm not surprised it threatened the Hornet - and F-16 later, the irony.

A good case could be made that an afterburning / supersonic A-7 was killed twice
- in the 1970's for the USN by the Hornet
- in the 1980's for USAF by the F-16

And that's the reason why I want it to happen in the 1960's - with the side effect of passing its afterburning TF41 either to the F-111B or... the Tomcat.

That's the real missed opportunity.

It is a pity USAF didn't put an afterburner on their A-7D circa 1966 to make them supersonics as a successor to... the F-105 Thunderchief. Unfortunately the Phantom essentially had taken that role, even with older J79s and at an even higher cost.

It boils to
- A-7F in 1966 to pass the TF41 to the Tomcat
- A-7F in 1972 to screw the Hornet
- A-7F in 1983 to screw the F-16

Whatever the engine, the A-7 being the son of Crusader, just screamed for an afterburner and supersonic speeds. The A-7F demonstrated that point beyond any doubt.

In passing, @F-14D - something that fascinates me with the A-7F is the rebuilding of older A-7s into A-7F.

It is not everyday that old subsonic airframes can be rebuild into supersonic / afterburning ones.
I can't think of any modern airfract that went through such changes.
It is quite easy to make a deep supersonic aircraft into a nearly subsonic one (B-1A / B-1B, cough)

But the other way around, and even more from existing airframes, is rather unique to the A-7F.
I often wonder if the Crusader DNA explained that feat.
 
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red admiral

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What would be the benefit of the supersonic performance? Better able to try to run from fighters?

Or are the real benefits in Sustained Turn Rate and SEP?
 

F-14D

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What would be the benefit of the supersonic performance? Better able to try to run from fighters?

Or are the real benefits in Sustained Turn Rate and SEP?
Everyone, don't get hung up on the supersonic speed issue. For this mission designing for supersonic capability adds virtually no value, and raises cost substantially. In fact It wasn't even a requirement for the CAS\BAI competition which is what broth forth the A-7F. Some, but not all, of the bidders had supersonic capability because they were adaptations of existing fighters that were already supersonic. Of course loaded down with the armaments necessary for CAS/BAI , they weren't supersonic anyway.

In the case of the A-7F, top speed wasn't the reason for the afterburner. Afterburner was added first, to enable takeoffs from shorter fields when necessary. Second, for more agility in the target area. Since the F100 in dry thrust put out about the same as the TF41, and the F110 put out more, you could fly the whole mission without touching the 'burner if you had an A-7D length runway and didn't need to do a lot of high maneuvering in the target area. . In fact, if you didn't touch the afterburner, the A-7F could fly a lot farther than the D. You could use the 'burner if needed, and still fly the distance the A-7D did.

Regarding pitching supersonic potential, that was just an added bonus point. The driver was to achieve those two key points I mentioned. When you put in the the thrust necessary to meet those goals, supersonic speed just sort of resulted.

A similar situation happened with the V-280. Bell didn't choose their required power to get 280 knots. The power was set at what was necessary to meet the Army's hot and high hover requirement. Once they had that, their calculations showed that with that power in level flight the bird would do 280 knots so that's what they announced as its speed. As it turned out, it went faster,
 
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F-14D

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Came across a tidbit. They apparently only flew the YA-7F supersonically once, to M1.6, to calibrate instrumentation. Like I said, supersonic capability wasn't that important to the design role.
 

isayyo2

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Came across a tidbit. They apparently only flew the YA-7F supersonically once, to M1.6, to calibrate instrumentation. Like I said, supersonic capability wasn't that important to the design role.
Not shocking by any means. How often did aircraft go supersonic over Vietnam? Especially when loaded with ordnance...

I’d be interested in a comprise 70s A-7F with a dry, but uprated TF41 or an F401 if we got lucky. Call it an “austere” NACF entry with a larger radome, but without the fuselage extensions. Maybe slap on some LERX’s and a APG-67 sized radar and call it a day. An A-7 with the 17,000 lbf TF41 would have near equal thrust to an F-8 in afterburner, though in a much stubbier fuselage. Ideally keep the mods simple enough so upgrades could be preformed during depot maintenance, like how F-14B's were planned to be upgraded into D models.

We could take it further by adding a CWI module to the new radar and wire in the capability for AIM-7's on the wing; if they can lug around four HARM's I think they could carry Sparrow's just fine. I don't picture A-7s swatting down MiGs like in Desert Storm, but having an inner layer CAP around the battle group would be beneficial. Depending on clearance, maybe the F-8's double rail AIM-9 launcher to could be added? At the very least for two Zuni pods for Fast-FAC.
 

F-14D

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Came across a tidbit. They apparently only flew the YA-7F supersonically once, to M1.6, to calibrate instrumentation. Like I said, supersonic capability wasn't that important to the design role.
Not shocking by any means. How often did aircraft go supersonic over Vietnam? Especially when loaded with ordnance...

I’d be interested in a comprise 70s A-7F with a dry, but uprated TF41 or an F401 if we got lucky. Call it an “austere” NACF entry with a larger radome, but without the fuselage extensions. Maybe slap on some LERX’s and a APG-67 sized radar and call it a day. An A-7 with the 17,000 lbf TF41 would have near equal thrust to an F-8 in afterburner, though in a much stubbier fuselage. Ideally keep the mods simple enough so upgrades could be preformed during depot maintenance, like how F-14B's were planned to be upgraded into D models.

We could take it further by adding a CWI module to the new radar and wire in the capability for AIM-7's on the wing; if they can lug around four HARM's I think they could carry Sparrow's just fine. I don't picture A-7s swatting down MiGs like in Desert Storm, but having an inner layer CAP around the battle group would be beneficial. Depending on clearance, maybe the F-8's double rail AIM-9 launcher to could be added? At the very least for two Zuni pods for Fast-FAC.
The thing is, the A-7F was intended to be an outstanding CAS/BAI asset, at a very low cost. There was no need, or even desire to add more A2A capability, which would do nothing but raise costs and not enhance the mission capability. USAF/USN already had fighters that would do that job better. Every one you used for CAP is one less you could use for strike, and strike is the reason for the plane's existence.

Regaling an upgraded dry TF41, why go to the expense of doing that when you already have two engines which would do the job better, and wouldn't require design and development work? Remember we'd have to be talking talking the 1980s. In the 1970s no one had any interest in this kind of vehicle, and for the time, the A7 was doing just great.. . If Navy wasn't willing to spend the beaucoup bucks it would take to bring the F401 to something usable for the aircraft that it was designed for, they certainly wouldn't cough up the money and time to put in the A-7. In the 1970s the F100 was coming and that would be a better choice; it was already there (sorta, had reliability and performance problems).

As far as LERX goes, they were already part of the A-7F design, although Vought called them "strakes".

My point is that prior to the CAS/BAI initiative of the 1980s, no one had any interest or need for such a vehicle.

FWIW
 

isayyo2

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Not disagreeing, just responding.
Every one you used for CAP is one less you could use for strike, and strike is the reason for the plane's existence
I was thinking in a similar vain to the A-6F slinging AIM-120's, purely a defensive option when the TU-22M Regiments conduct their alpha strikes against the battle group. Have the F-14s in the outer air battle as planned, with everything else supporting the inner ring/plugging gaps.
Regaling an upgraded dry TF41, why go to the expense of doing that when you already have two engines which would do the job better, and wouldn't require design and development work?
Plainly because I'm biased towards the design and I'm trying to fit it into the narrative :p A bit more seriously, the TF41 is the safer option in the 70s with Pratt busy fixing the F100 and the F-15 having engine priority. If this is some bizzaro world where the F401 and the NACF is cancelled then the TF41 is the only option? The twin F404 A7 never struck me as realistic, at least if using existing airframes was the goal.
If it’s the 80s, then I completely agree with you.
 

F-14D

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Not disagreeing, just responding.
Every one you used for CAP is one less you could use for strike, and strike is the reason for the plane's existence
I was thinking in a similar vain to the A-6F slinging AIM-120's, purely a defensive option when the TU-22M Regiments conduct their alpha strikes against the battle group. Have the F-14s in the outer air battle as planned, with everything else supporting the inner ring/plugging gaps.
Regaling an upgraded dry TF41, why go to the expense of doing that when you already have two engines which would do the job better, and wouldn't require design and development work?
Plainly because I'm biased towards the design and I'm trying to fit it into the narrative :p A bit more seriously, the TF41 is the safer option in the 70s with Pratt busy fixing the F100 and the F-15 having engine priority. If this is some bizzaro world where the F401 and the NACF is cancelled then the TF41 is the only option? The twin F404 A7 never struck me as realistic, at least if using existing airframes was the goal.
If it’s the 80s, then I completely agree with you.
My thought is that the uprated TF41 would require too much work and time for only 2,000 lbs increase, especially with Vietnam being hot and heavy at the time , With the '60s being when the A-7D/E was invented, if they had wanted to do an uprated TF41, they would have done that from the get-go.
 
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isayyo2

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Allison did fly their 17,500 lbf "-B32" engine in September 72 in a YA-7H, about three years after the A-7E's first flight. I only have a snippet of the article, and I'm not 100% sure if the A-7's inlet would be to be increased in order to fully use the extra 2,500 lbf of thrust.

17,500 lb TF41.png
 
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