What would an A-6F or A-7F like upgrade to the F-111 look like?

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apparition13

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In the mid to late 80s we get the massively upgraded A-7F and A-6F, both with new engines and avionics. Sadly neither goes into production. The question that comes to mind is what would a similar upgrade of the F-111 look like, an F-111J if you will. Perhaps an A-6F like new build in place of the F-15E, or maybe an A-7F rebuild.

What engines, what avionics, what capabilities? Any changes to the airframe, like in the A-7F? And if it was produced and deployed, how would it have performed?

In short, how do you envision a putative F-111J?
 
There was the OTL Avionics Modernisation Program (AMP) which AFAIK was to have included every surviving F-111 (and FB-111) in the USAF. I don't know how many aircraft actually had it done, but @BlackBat242 and/or @Scott Kenny may know. The Wikipedia article on the F-111 says that some of them had their original TF30 engines replaced by more powerful marks of that engine.
 
A quote from the Air Vectors article on the F-111 (https://www.airvectors.net/avf111.html).
From 1986, the EF-111As were refitted with more powerful TF30-P-9 engines. From 1989, they were fitted with the "Avionics Modernization Program (AMP)" kit, which included:
  • Improved radar systems.
  • A ring laser gyro INS.
  • Capability to support a Global Positioning System satellite navigation network receiver.
  • New digital processors, cockpit displays, and communications kit.
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One of the proposed upgrades to the FB-111 was replacing the TF30s or F101s. FB-111H. This also had an enlarged aft fuselage to hold the much bigger engines and more fuel. That was to replace the B-1.

A-7F was intended to use the F100 or F110. F-14Ds show that you can stuff the F110 into the same rough volume as a TF30.

The better option would be a swap with probably the afterburning TF41 proposed for the A-7F (TF41 with F100 afterburner grafted on). Better fuel economy.

As to the avionics update, I'd want the same set as the A-6F.
 
NOMISYRRUC said:
There was the OTL Avionics Modernisation Program (AMP) which AFAIK was to have included every surviving F-111 (and FB-111) in the USAF. I don't know how many aircraft actually had it done, but @BlackBat242 and/or @Scott Kenny may know. The Wikipedia article on the F-111 says that some of them had their original TF30 engines replaced by more powerful marks of that engine.
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I have no idea of the numbers run through that program.

The TF30-3 of the F-111A & C produced 10,750lb dry & 18,500lb afterburning.
The TF30-9 of the F-111D & E produced 12,000lb dry & 19,600lb afterburning.
The TF30-100 of the F-111F produced 15,000lb dry & 25,100lb afterburning.
In 1985 the F-111Fs were re-engined with the TF30-111 which produced 17,895lb dry & 25,111lb afterburning.
The TF30-7 of the FB-111A produced 12,500lb dry & 20,350lb afterburning.
The TF30-3 of the EF-111A produced 10,750lb dry & 18,500lb afterburning.
In 1986 the EF-111As were re-engined with the TF30-109RA which produced 12,000lb dry & 20,840lb afterburning.

A navalized version of either the TF30-100 or TF30-111 would have been a good upgrade for the F-14 to replace the TF30-412/414 which produced 12,350lb dry & 20,900lb afterburning - without the added modifications that were required for the F110-400 of 1987 which produced 16,800lb dry and 27,000lb afterburning.
 
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I do know that circa 1969 SNECMA got 10300 kg of thrust out of the TF306E, which translates as 22,700 pounds. Quick search at Google books brings Flight International, 1969, and 22,820 pounds: pretty close.
 
BlackBat242 said:
I have no idea of the numbers run through that program.

The TF30-3 of the F-111A & C produced 10,750lb dry & 18,500lb afterburning.
The TF30-9 of the F-111D & E produced 12,000lb dry & 19,600lb afterburning.
The TF30-100 of the F-111F produced 15,000lb dry & 25,100lb afterburning.
In 1985 the F-111Fs were re-engined with the TF30-111 which produced 17,895lb dry & 25,111lb afterburning.
The TF30-7 of the FB-111A produced 12,500lb dry & 20,350lb afterburning.
The TF30-3 of the EF-111A produced 10,750lb dry & 18,500lb afterburning.
In 1986 the EF-111As were re-engined with the TF30-109RA which produced 12,000lb dry & 20,840lb afterburning.

A navalized version of either the TF30-100 or TF30-111 would have been a good upgrade for the F-14 to replace the TF30-412/414 which produced 12,350lb dry & 20,900lb afterburning - without the added modifications that were required for the F110-400 of 1987 which produced 16,800lb dry and 27,000lb afterburning.
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The TF30-100 and 111 still suffered from the same sensitivity to airflow disruptions. While it would have been nice to have the increased thrust and push the F-14 closer to 1:1 it still would not have been a true fighter engine and the same engine management precautions would have been needed. Really, the USN should have stayed the course with the PW F401 but the F-14A was under enough scrutiny and the teething issues with the F401 was compounding the situation. As it was the PW TF30 P-412-A was seen as a safer option from the vantage point of the F-14A fleet integration. Ironically the IIAF did have some discussions with Pratt & Whitney regarding refitting their F-14's with the F401 but they did not come to fruition for whatever reasons.

The TF30 was perfect for the F-111 and its mission.
 
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Run the F-111 fleet update in conjunction with the USN's F-14D program, incorporating the same F110-GE-400 turbofans inplace of both aircraft's legacy TF30 turbofans. With the engineering required to adjust the F-14's engine bay and mounts, being incorporated into the F-111's.
The purpose of swapping the legacy TF30's for more modern F110-GE-400's not just giving the net benifit of addition thrust. But importantly for the F-111 and it's principle role of long-range strike/interdiction. The F110 affording the F-111 far better range and endurance, when one considers that the instillation of the F110 into the F-14D 'improved its range by sixty percent more range or one third more time on station.', or so I've read....
Also, the increase in dry thrust of the F110 vs that of the TF30-100, means that the upgraded F-111 would not have to use afterburning thrust as often....Again, contributing to both range performance and cost savings in terms of fuel consumption costs....

What about replacement of the Crew Escape Module, with ejection seats? This would undoubtedly save a lot of weight, maintance, and maintance man hours.



Regards
 Pioneer
 
F110-GE-400 turbofans, Airborne Self Protection Jammer, the AN/APG-71 radar, Joint Tactical Information Distribution System, Tactical Air Reconnaissance Pod System (TARPS), and LANTIRN's Fast Tactical Imagery (FTI) system. Add in JDAM and AMRAAM.
 
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pathology_doc said:
It's a major structural change. It might not save as many man-hours as it costs to make the change.
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This applies to so many suggested improvements to aircraft, virtually everything is baked into the design and cannot be changed without so much effort and expense that makes it all not worthwhile.

The RAAF re-engining it's F111Cs with F111D engines would have been done specifically because it was cheap and easy. The engines themselves would have been bought at scrap value, the US would likely have changed the category of these engines for this purpose, and fitted more or less easily into the F111C engine bays without major work. Once the price of an engine goes from $5,000 (a guess) to $5,000,000 each for 50+ engines and the fitment engineering stretches into the millions per ~30 aircraft you're starting to get a significant portion of a new aircraft purchase cost.
 
Rule of cool said:
The RAAF re-engining it's F111Cs with F111D engines would have been done specifically because it was cheap and easy. The engines themselves would have been bought at scrap value, the US would likely have changed the category of these engines for this purpose, and fitted more or less easily into the F111C engine bays without major work. Once the price of an engine goes from $5,000 (a guess) to $5,000,000 each for 50+ engines and the fitment engineering stretches into the millions per ~30 aircraft you're starting to get a significant portion of a new aircraft purchase cost.
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But if the USAF was doing the engineering for their F-111F/Gs to have the same engines as F-14Ds...
 
Rule of cool said:
This applies to so many suggested improvements to aircraft, virtually everything is baked into the design and cannot be changed without so much effort and expense that makes it all not worthwhile.
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Even worse when it happens partway through the design process (the later, the worse).
 
Pioneer said:
What about replacement of the Crew Escape Module, with ejection seats? This would undoubtedly save a lot of weight, maintance, and maintance man hours.
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From memory, the Crew Escape Capsule was designed to protect the crew in the event of a supersonic bailout. F-111 was a M2+ bird.
 
Scott Kenny said:
But if the USAF was doing the engineering for their F-111F/Gs to have the same engines as F-14Ds...
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Sure, the US operates on a different level to the rest of the world, things make sense in the US that don't elsewhere. That said, the 80s F14 re-engine programme operated alongside new production F14s whereas the F111 ceased production in 1976 and by the late 80s the F15E was about to enter production to replace the F111.
 
Rule of cool said:
That said, the 80s F14 re-engine programme operated alongside new production F14s whereas the F111 ceased production in 1976 and by the late 80s the F15E was about to enter production to replace the F111.
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The F-111D/E/Fs were ordered in 1968/69, and were only delivered 1970-1976. So they would have only been 15-20 years old in 1991.

It really depends on how many changes would be required for hanging an F110 in a bay designed around the TF30. For what it's worth, it appears that the TF30 is actually the physically larger of the two engines, 49-52" maximum diameter, while the F110 has a 46.5" maximum diameter.

And the "F-14 w/ F110" program saw F-14A+/F-14Bs in service in 1987, so the oldest of the F-111s only would have been 15 years old at that point.
 
Scott Kenny said:
The F-111D/E/Fs were ordered in 1968/69, and were only delivered 1970-1976. So they would have only been 15-20 years old in 1991.

It really depends on how many changes would be required for hanging an F110 in a bay designed around the TF30. For what it's worth, it appears that the TF30 is actually the physically larger of the two engines, 49-52" maximum diameter, while the F110 has a 46.5" maximum diameter.

And the "F-14 w/ F110" program saw F-14A+/F-14Bs in service in 1987, so the oldest of the F-111s only would have been 15 years old at that point.
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Firstly, I have no doubt it can be done in engineering terms, after all the TF30 F14s were re-engined with F110s.

However, this shows the US dilemma that's different to other countries; does the US do a massive upgrade on 15-20 year old aircraft of build new aircraft to keep industry perking along and introduce new technology that way.

In any case the F111s TF30s were rebuilt using TF30-100 components, which is why the TF30-P3 etc were re-designated P103.
 
Rule of cool said:
However, this shows the US dilemma that's different to other countries; does the US do a massive upgrade on 15-20 year old aircraft of build new aircraft to keep industry perking along and introduce new technology that way.
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I mean, every nation has that kind of dilemma.

The UK dealt with the same issues, and generally ended up proposing doing the upgrades because new aircraft were too expensive, then canceling the upgrades because the upgrades were too expensive.
 
*sigh*. Throwing red card.

With respect, @ScottKenny, you should know better than that. Only fanbois measure aircraft lives purely in calendar terms.

If you would like to have a fact-based discussion, please refer to Don Logan's 1998 book "General Dynamics F-111 Aardvark" which among other things, pictures almost every F-111 built, with (where available) total airframe hours at retirement. Rather surprisingly, a cursory glance shows the Ds retiring with lower hours (about 4000) than the Es and Fs (in the 5000 - 6000 range) in the mid-1990s - the very period that you proposed that these airframes be upgraded with new systems - just in time to have the wings fall off (figuratively).

Very few aircraft retired with much more than 6000 hours which suggest an absolute IAT (Individual Aircraft Tracking) Fatigue limit somewhere at about this hour range. (Don't forget that achilles heel of the D6AC Steel wing carry though structure...)

That the older F-111D were retired with more fatigue life remaining -- that likely reflects their lower flight time accumulation due to their abysmal mission-capable and flight rates during the 70's and 80's due to excruciatingly poor R&M of their avionics (as well as "hollow force" issues of the 70's).

The far more reliable E's and F's were on the other hand spent most of their lives on the "tip of the spear" and were ridden hard and put away wet by 1996, when replaced by the F-15E Mudhens. By no stretch of the imagination could the F-111 be considered a "Dual Role Fighter" as was the Strike Eagle.
 
That is a book I have not read.

aim9xray said:
By no stretch of the imagination could the F-111 be considered a "Dual Role Fighter" as was the Strike Eagle.
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There's no "dual role" about the F-111. It's a medium bomber. It's got somewhere between zilch and zero air-to-air capabilities.
  • No gun (yes there was one designed but I'm not aware of it ever being flown in combat, Pave Tack being preferred),
  • no AAM bigger than Sidewinders and it's got maneuvering limits with the TF30s (which would go away with F110 re-engine)
  • And IIRC all of 1 claimed kill in air-to-air.
 
jeffb said:
From memory, the Crew Escape Capsule was designed to protect the crew in the event of a supersonic bailout. F-111 was a M2+ bird.
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In all due respect jeffb, I'm under the impression that a combat ladden F-111 was not capable of Mach 2. The Mach 2+ performance was achieved in a clean configuration - no drop tanks/no external weapons. The exception would be the RF-111C and FB-111A, utilising the internal weapons bay for reconnaissance pallet and nukes respectively.

Regards
Pioneer
 
cccgong said:
Missile warning satellites will only tell you something is coming at you from a general direction and time, similar with a search radar. For BM/HGV you will need much more precise targeting information (than aircraft due to a much more limited interception window) and also discrimination from possible decoys. This means you will need a chonky radar for the engagement.
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Scott Kenny said:
That is a book I have not read.


There's no "dual role" about the F-111. It's a medium bomber. It's got somewhere between zilch and zero air-to-air capabilities.
  • No gun (yes there was one designed but I'm not aware of it ever being flown in combat, Pave Tack being preferred),
  • no AAM bigger than Sidewinders and it's got maneuvering limits with the TF30s (which would go away with F110 re-engine)
  • And IIRC all of 1 claimed kill in air-to-air.
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Tactical bomber, not medium. It had significant range to pull off 1500 to 2000 mile combat radius. If they stuck on retired Tomcat radars, which it easily had the space in the nose to accommodate, it should have upgraded to AMRAAM-A at the time for self escort. FB-111A had the massive tail mounted jammers, which were never truly replaced and then Prowlers also got canned to make matters worse. I always thought the Prowlers were the priority to update with non-afterburning F100s, too.

edit: spelling
 
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What were the main areas of structural fatigue that were a limit on the operational life of the F-111? I thought the wing carry-through box issue in particular was something corrected after they set up that inspection procedure to find the ones with flawed metallurgy.
 
Scott Kenny said:
I mean, every nation has that kind of dilemma.

The UK dealt with the same issues, and generally ended up proposing doing the upgrades because new aircraft were too expensive, then canceling the upgrades because the upgrades were too expensive.
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I think the US' dilemma is different to other countries because of the size of its military and the industry that backs it. While the US could upgrade its F111s, or whatever other fleet you might name, there is usually pressure from industry to build a new aircraft which is quite often waiting in the wings ready to go. Smaller powers have much less of this pressure due to the smaller size of their industry.
 
Pioneer said:
The exception would be the RF-111C and FB-111A, utilising the internal weapons bay for reconnaissance pallet and nukes respectively.
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Indeed, the plane was designed around an ability to deliver nuclear (or conventional) weapons using a LO-LO-HI mission profile that included a Mach 1.2 dash over the target for weapons delivery.

Obviously, bailout at M1.2 and 200ft altitude presented risks to crew safety great enough to warrant an ejection pod.

Tall tale possibly...
www.twz.com

The F-111 Was Faster Than You Think

The swing-wing F-111 was capable of reaching far higher speeds than most realize, and it did so on multiple occasions.
www.twz.com www.twz.com
 
Scott Kenny said:
I don't think I'm willing to believe that.
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A former pilot I spoke to at the SAC museum (near Omaha, NE) seemed to be pretty proud of it. Something about the glass limited its speed, but he said it was built for high speeds over something like an F-15 with the bubble cockpits. I think he said 70 degree wing sweep made it a relatively tiny head-on target. Something about being untouchable near sea level where they could supposedly outrun everyone else. Pretty sure the F-105G guys used to say that, too. I'm old enough to remember one of the F-111's got downed over Libya whereas A-6s dropped bombs over heavily defended targets too and did not.
 
Those Mach 2.5+ F111 stories are believable enough if they're the rare exception rather than the rule, much like how a planes rated for 9G turns can actually pull 11G in extreme situations. In any case the F111 was nothing if not fast, supersonic on the deck with certain weapons loads.
 
I have heard first hand accounts of the F-111 definitely being capable of higher than normal speeds. This includes references to such during the development of the P-108 variant of the TF30.
 
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It would have made an excellent high speed interceptor to replace the F-106. You don't need maneuverability to down bombers. I wouldn't have used the phoenix on it, like the USN did, however. Just AMRAAMs and maybe a couple of sidewinders if they decided they could get in close enough. Maybe they could have redesigned the cockpit windscreen and canopy to handle Mach 3. Then the USAF would have had their Mach 3 interceptor they wanted, without all of the ridiculousness that went with the YF-12A. Having to melt the oil to pour into the engines isn't ideal for an interceptor that has to stand on alert. That would have been a good replacement for the Canadian F-101B's as well.
 
GTX said:
I have heard first hand accounts of the F-111 definitely being capable of higher than normal speeds. This includes references to such during the development of the P-108 variant of the TF30.
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Sure, I'll buy 2600kph. I'll buy M2.6 or 2.7ish. I'm not buying Mach 3.
 
Mach 1 at altitude is 1080 km per hour. Mach 2.7 would be 2916 kph.
 

View topic - Max Speed of Cold War Era Aircraft • F-16.net

Military aviation forum since 2003, with high quality discussion focusing on the F-16, F-35 and F-22 jet fighters and the C-130.
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Posted by johnwill 18 Dec 2008
"Somewhere in my stacks of keepsakes I have a photo of an F-111 panel during a low level test flight over the Gulf test range off Galveston. It shows 890 KIAS, 1.37 M, 3500 ft. As far as I know, there was never any attempt to set a record. No matter what, I gotta admire the F-4 crew for having large solid gold ones.

The newspapers in Galveston reported a possible earthquake that day and several shrimp boats out in the Gulf reported hearing a really loud explosion."
 
Scott Kenny said:
There's no "dual role" about the F-111. It's a medium bomber. It's got somewhere between zilch and zero air-to-air capabilities.
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And indeed, the F-111B, which was supposed to be the Navy's long-range interceptor armed with AIM-54, was a significantly different aircraft ahead of the cockpit. I heard the F-111F had probably the best thrust-weight ratio of the lot, but it's still a sluggard compared to the Tomcat and Eagle and I don't know for sure if it can even optimally use the AIM-9L or subsequent.

F-111D was originally going to get Sparrow (AIM-7G with a seeker tuned to its radar), but that was cancelled.
MadRat said:
If they stuck on retired Tomcat radars, which it easily had the space in the nose to accommodate, it should have upgraded to AMRAAM-A at the time for self escort.
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And where's it going to put the nav-attack radar and FCS which it needs for its primary mission? Drop an AWG-9 in, you've basically got an F-111B with a longer nose.
 
pathology_doc said:
And where's it going to put the nav-attack radar and FCS which it needs for its primary mission? Drop an AWG-9 in, you've basically got an F-111B with a longer nose.
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Ever hear of APG-71? It wasn't your father's AWG-9. Many functions were consolidated into one unit by then. F-14 needed LANTIRN to get a fraction of F-111's other cspabilities that were already integrated into tactical F-111s.

I can imagine Australian Super Hornets may not have happened if their F-111s had APG-71 and AMRAAM. JORN Phase 4/5 certainly become much more interesting.
 
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MadRat said:
I can imagine Australian Super Hornets may not have happened if their F-111s had APG-71 and AMRAAM.
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I can imagine airframe-life considerations having some input into that decision. "New wine in old wineskins" and all that.

IIRC the Aussie -111s were among the physically oldest and earliest to be ordered, even if the Australians didn't get them for many years.
 
Regarding modernized F-111s, I would bet that any major upgrade would have primarily targeted the EF-111 (Raven). However, with the introduction of the F-15E Strike Eagle into service, the F-111 becomes economically expensive to maintain, especially given the heavily worn-out airframes.
 

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