Did the F-108 or F-12 hold any real promise as operational interceptors?

[Conslaw]

The USAF had two serious Mach-3 interceptor programs, the North American F-108 and the Lockheed F-12 (prototypes flying as the YF-12A). Poth programs were cancelled before operational. If either type had become operational, how do you think the planes would have evolved?

 

[FLYBOYJ]

Both aircraft were designed against a threat, which was later found out, did not exist, that being a large Soviet Bomber force. The YF-12 was offered to the USAF after the cancellation of the XF-108. It was big and fast but was only able to perform long range, high speed intercept missions. I consider the XF-108 a contemporary of the CF-105. On paper it would have been faster and had a greater range. In hindsight, neither aircraft were necessary as the Soviet Union never produced a huge bomber force and put most of their offensive nuclear capabilities in missiles.

 

[SaparotRob]

Wasn't the F-15 designed for a non existent threat? The threat that existed until that MiG-25 visited Japan and the west got a good look at it?
It's ironic to me as the Foxbat was designed to counter a nonexistent threat.

 

[GTX]

What an operational F-108 might have looked like:

 

[FLYBOYJ]

Wasn't the F-15 designed for a non existent threat? The threat that existed until that MiG-25 visited Japan and the west got a good look at it?
It's ironic to me as the Foxbat was designed to counter a nonexistent threat.

Yeas and no - the west thought the MiG-25 was a lot more capable but there was still a need for an air superiority fighter that can totally dominate any Soviet product in any environment to include "Rules of Engagement" (ROE) that may limit the aircraft from fully exploiting it's capabilities due to political situations (like Vietnam). The F-14, although a naval fighter, had the same situation.

 

[GTX]

Another possible operational F-108 image:

 

[GTX]

If either had entered operational service I presume they would have ended up serving instead of the likes of F-106s, so in Air Defense Command / Aerospace Defense Command and Air National Guard units. I wonder if there would have been a chance of Candaian ones as well?

 

[SaparotRob]

NAA sure makes 'em pretty.

 

[FLYBOYJ]

If either had entered operational service I presume they would have ended up serving instead of the likes of F-106s, so in Air Defense Command / Aerospace Defense Command and Air National Guard units. I wonder if there would have been a chance of Candaian ones as well?

Well the CF-105's demise had a lot of politics involved and the program was in the bulls-eye of its opponents years before the first one was built. In it's day, the CF-105 was one of the most advanced combat aircraft in the world, so when the Diefenbaker Government killed it, many people were upset. When the F-108 program was cancelled, there was hardly a peep.

 

[GreenKnight121]

The F-15 was also built not just to counter the MiG-25, but to "one-up" the MiG-23 Flogger.

Yes... we didn't just have "Foxbat Fright"... we also had "Frogger Fever"!

Many people now compare the Flogger to the F-4 Phantom II as "near-equals save for avionics"- at the time we didn't understand just how behind the Soviets were in avionics, and considered the MiG-23 (first flight in 1967, just like the public showing of the MiG-25) to be better than the F-4!

It is NEVER a good idea to deliberately go to war with equal equipment to your foe... you always try to show up with better and hope you can afford enough of them, and the Soviets were looking like they were going to build a lot of Floggers, so either we needed to put an improved F-4* back into production (bad idea) or come up with a new air-superiority fighter that was significantly better than the Flogger or F-4.

The F-X program that had started in 1965 as a F-100/etc replacement just got the USAF the A-7 (they had wanted something like the F-5E), and was extended in 1966 to produce an F-4 replacement. This was better than the MiG-23, but not quite good enough to counter what we in 1967 believed the MiG-25 to be, so a redefinition for an even better (and more-expensive) air-superiority aircraft was ordered.

So you see, the F-4 replacement program was already underway, boosted by the appearance of the MiG-23 - the MiG-25 was just the "final straw" to get Congress to approve the program.


* One possibility could have been McD/D's proposed F-4FVS (proposed to the USN in late 1965) - with a shoulder-mounted variable-sweep wing!
The USN obviously passed on that in favor of the F-14, for many similar reasons to the USAF's pushing for the F-15... but the primary mission & design choices of the F-14 and F-15 were too different for another joint buy.

 

[drgondog]

The F-15 was also built not just to counter the MiG-25, but to "one-up" the MiG-23 Flogger.

Yes... we didn't just have "Foxbat Fright"... we also had "Frogger Fever"!

Many people now compare the Flogger to the F-4 Phantom II as "near-equals save for avionics"- at the time we didn't understand just how behind the Soviets were in avionics, and considered the MiG-23 (first flight in 1967, just like the public showing of the MiG-25) to be better than the F-4!

It is NEVER a good idea to deliberately go to war with equal equipment to your foe... you always try to show up with better and hope you can afford enough of them, and the Soviets were looking like they were going to build a lot of Floggers, so either we needed to put an improved F-4* back into production (bad idea) or come up with a new air-superiority fighter that was significantly better than the Flogger or F-4.

The F-X program that had started in 1965 as a F-100/etc replacement just got the USAF the A-7 (they had wanted something like the F-5E), and was extended in 1966 to produce an F-4 replacement. This was better than the MiG-23, but not quite good enough to counter what we in 1967 believed the MiG-25 to be, so a redefinition for an even better (and more-expensive) air-superiority aircraft was ordered.

So you see, the F-4 replacement program was already underway, boosted by the appearance of the MiG-23 - the MiG-25 was just the "final straw" to get Congress to approve the program.


* One possibility could have been McD/D's proposed F-4FVS (proposed to the USN in late 1965) - with a shoulder-mounted variable-sweep wing!
The USN obviously passed on that in favor of the F-14, for many similar reasons to the USAF's pushing for the F-15... but the primary mission & design choices of the F-14 and F-15 were too different for another joint buy.


View attachment 677037View attachment 677038View attachment 677039View attachment 677040View attachment 677041

Both the F-16(first) then follow up F-15 arose from John Boyd inspired crusade demonstratng poor energy manueverabilty of Century series fighters (and F-4) in comparison to Soviet fighters. The Pentagon hated Boyd but capitulated to the facts. The primary difference between F-15 and F-16 was size dictated by Radar, as well as mission growth capability of F-15 over F-16

 

[Glider]

What an operational F-108 might have looked like:

View attachment 676319

At first glance I thought the USAF were thinking of buying the TSR2

 

[Thumpalumpacus]

Both the F-16(first) then follow up F-15 arose from John Boyd inspired crusade demonstratng poor energy manueverabilty of Century series fighters (and F-4) in comparison to Soviet fighters. The Pentagon hated Boyd but capitulated to the facts. The primary difference between F-15 and F-16 was size dictated by Radar, as well as mission growth capability of F-15 over F-16

Especially in an era where missile locks still had relatively limited envelopes, maneuverability was very important. It still is today, in a knife-fight, but with modern, long-range all-aspect missiles, less so.

 

[GreenKnight121]

Both the F-16(first) then follow up F-15 arose from John Boyd inspired crusade demonstratng poor energy manueverabilty of Century series fighters (and F-4) in comparison to Soviet fighters. The Pentagon hated Boyd but capitulated to the facts. The primary difference between F-15 and F-16 was size dictated by Radar, as well as mission growth capability of F-15 over F-16

Interesting that somehow you think that the program that started first (1966), saw the selection of the winner first (1969), and produced a flying prototype first (1972) is somehow a "followup" program?

Yes, those are the dates for the F-15.

Here are the dates for the F-16:
Initiation of design concept studies: 1969 (F-15 final selection same year)
Creation of formal program for light-weight fighter: 1971 (5 years after F-15 program creation)
Selection of finalists for LWF flying prototypes: 1972 (F-15 first flight year)
First flights of YF-16 & YF-18: 1974 (F-15B delivery to USAF to establish training squadron)
Selection of winner: 1975
Production F-16A first flight: 1978 (F-15C & F-15D first flights)
First delivery to USAF: 1979 (F-15 first air-air "kill" in combat by IAF)

The "Fighter Mafia" did, during the 1965-68 period, succeed in getting the F-15 reduced in size and weight from its early concepts... but it was still considered "too big & expensive to buy in sufficient numbers" - which only then resulted in the LWF program being created, leading to the F-16!

The F-16 was a "mission-shrink" follow-on to the "full-capability" F-15!

 

[drgondog]

Interesting that somehow you think that the program that started first (1966), saw the selection of the winner first (1969), and produced a flying prototype first (1972) is somehow a "followup" program?

Yes, those are the dates for the F-15.

Here are the dates for the F-16:
Initiation of design concept studies: 1969 (F-15 final selection same year)
Creation of formal program for light-weight fighter: 1971 (5 years after F-15 program creation)
Selection of finalists for LWF flying prototypes: 1972 (F-15 first flight year)
First flights of YF-16 & YF-18: 1974 (F-15B delivery to USAF to establish training squadron)
Selection of winner: 1975
Production F-16A first flight: 1978 (F-15C & F-15D first flights)
First delivery to USAF: 1979 (F-15 first air-air "kill" in combat by IAF)

The "Fighter Mafia" did, during the 1965-68 period, succeed in getting the F-15 reduced in size and weight from its early concepts... but it was still considered "too big & expensive to buy in sufficient numbers" - which only then resulted in the LWF program being created, leading to the F-16!

The F-16 was a "mission-shrink" follow-on to the "full-capability" F-15!

I stand corrected on F-15 start date.

 

[MIflyer]

I think that both the F-108 and F-12 were based on not only trying to intercept the enemy bombers as far out as possible but also to have a second pass capability in case they missed the first time. It takes a very fast airplane to be going supersonic and then turn around and tail chase the bomber it failed to kill on the first try.

The F-12 would have used AIM-47 AAMs which were more or less an early Phoenix.

The F-108 was based on B-70 technology. The Revell kit of it was quite popular for a limited time but they only made one production run due to the cancellation. In those days Revell was located not too far from NAA.

 

[Zipper730]

Well the CF-105's demise had a lot of politics involved and the program was in the bulls-eye of its opponents years before the first one was built. In it's day, the CF-105 was one of the most advanced combat aircraft in the world, so when the Diefenbaker Government killed it, many people were upset. When the F-108 program was cancelled, there was hardly a peep.

Ironic especially when the F-108 was actually better in a number of ways

1. Speed
   • XF-108A: Mach 3
   • CF-105: Somewhere between Mach 2-3
   • Verdict: F-108 could achieve a higher protracted speed
2. Range
   • XF-108A: ~1000 nm
   • CF-105: A few hundred
   • Verdict: F-108 has superior range (and at a superior speed to boot).
3. Maneuverability
   • XF-108A: 5.33 g @ 80% fuel-load (8g ultimate)
   • CF-105: 7g or 7.5g (I forgot) ultimate-rated at 47000 lb. (IIRC).
   • Verdict: F-108 had a higher load-factor.
4. Avionics
   • CF-105
     • Flight & Engine Controls
       • FBW on all control surfaces with integrated SAS (something that reminds me a bit of the F-16).
       • Safety mode which would limit g-load and attitude in the event of structural damage.
       • Mechanical bank-up on one hydraulic line in event of FBW failure.
     • Radar & FCS: The system was comparable to that used on the F-102A, F-101B, and F-106A designs from what I recall.
   • XF-108A
     • Flight & Engine Controls
       • Redundant mechanically-signaled hydraulic system (AFAIK)
       • Engine controls used an electrically-controlled analogue system.
     • Radar & FCS: AN/ASG-18
       • It was the largest radar designed for use aboard a fighter aircraft (40" radome).
       • It had a range that exceeded the F-102A, F-101B, and F-106A by a substantial margin.
       • It was a pulse-doppler radar which allowed it to remove objects that are moving at very low speed (50 kn. and below based on what was revealed in tests).
       • It was suspected of possessing sufficient processing power to track an ICBM in flight
         • This actually resulted in the AN/ASG-18 and the GAR-9/AIM-47 remaining in development after the XF-108 was cancelled
         • Test were done in 1962 with a modified B-58 (A/C 55-665) which remain unspecified.
   • Verdict
     • Flight & Engine Controls: CF-105 had more sophisticated flight-control systems; XF-108 had more sophisticated engine-control systems
     • Radar & FCS: XF-108 had superior radar.
5. Armament
   • CF-105
     • Air-to-Air
       • 8 x AIM-4 Falcon
       • 2-4 x AIR-2 Genie
     • Air-to-Ground
       • Up to 4000 lb. of ordinance
   • XF-108A
     • Air-to-Air: 3 x AIM-47
   • Verdict
     • Air-to-Air: While the aircraft can carry a large number of missiles and a more versatile armament loadout, the XF-108's AIM-47 is a far superior weapon than the AIM-4 or AIR-2 owing to the fact that it has far superior range, a proximity fuse, active terminal-guidance, and provision for home-on-jam capability. While the AIR-2 Genie has a nuclear warhead, the AIM-47 could be fitted with one too.
     • Air-to-Ground: CF-105 wins by default.
     • Ultimate: Both aircraft were designed as interceptors, so the XF-108A was the better arrangement.

While the CF-105 has an advantage in superior flight-control and stability augmentation, as well as an air-to-ground capability (the weapons pack was also something that would make for more armament options), the XF-108A was ultimately the better performer with better radar and longer-ranged missiles.

Both the F-16(first) then follow up F-15 arose from John Boyd inspired crusade demonstratng poor energy manueverabilty of Century series fighters (and F-4) in comparison to Soviet fighters.

Actually, Boyd made some errors when calculating the F-4's performance. Early figures had often indicated the MiG-21 would be able to outmaneuver and out-sustain the F-4's in turns. While, the F-4 had a higher stall-speed that meant it couldn't turn as tight as the MiG-21, it could actually sustain higher loads in turns up to around 30000-32000', out-accelerate and out-climb the MiG-21 up to 30000-32000' (I'm not sure if this has to do with AoA, inlet efficiency, or engine characteristics -- it's beyond my pay-grade).

I do, regardless, agree with Boyd's basic premise: Fighters should be built with the ability to maneuver across a wider range of altitudes (so more overall power, lower stall-speeds, etc.)

 

[nuuumannn]

Well the CF-105's demise had a lot of politics involved and the program was in the bulls-eye of its opponents years before the first one was built. In it's day, the CF-105 was one of the most advanced combat aircraft in the world, so when the Diefenbaker Government killed it, many people were upset. When the F-108 program was cancelled, there was hardly a peep.

Yup, nationalism accounted for that bad press, the CF-105 meant so much more to Canada than as an advanced aircraft programme for its air force. The British looked at the CF-105 as an interceptor at one stage but decided against it because its performance fell short of the F.155T interceptor programme. That project, which was looked to be fulfilled by the Fairey Delta tender eventually fell victim to Duncan Sandys' 1957 Defence White Paper, speaking of national outcries...

F155T Design Submissions

Monograph page on F155T designs

rp-one.net

 

[GTX]

I

Yup, nationalism accounted for that bad press, the CF-105 meant so much more to Canada than as an advanced aircraft programme for its air force. The British looked at the CF-105 as an interceptor at one stage but decided against it because its performance fell short of the F.155T interceptor programme. That project, which was looked to be fulfilled by the Fairey Delta tender eventually fell victim to Duncan Sandys' 1957 Defence White Paper, speaking of national outcries...

F155T Design Submissions

Monograph page on F155T designs

rp-one.net

Indeed, even decades later some clowns were trying to push the CF-105 as an alternative to the F-35 to replace the CF-188s. Lunacy.

 

[nuuumannn]

Lunacy.

Yup, nothing like a bout of national pride as a cure for common sense.