PW F401-PW-400 and GE F110-400 for F-14

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Bruno Anthony

I miss the Cold War
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Can anyone post whatever they have on the P&W F401-100 engine for the F-14 and if possible how it compared with the GE F110 that actually went into the F-14D?
 
I think if you go back to edit your first post you can change the title, though I'm not sure. Give it a try.
 
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Bruno Anthony said:
Can anyone post whatever they have on the P&W F401-100 engine for the F-14 and if possible how it compared with the GE F110 that actually went into the F-14D?
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It (F401) was better by 10 years. And it would have saved Goose's life!
 
Nobody has info on the f401 or how it compares with the F110? On this website?! Come on now don't be shy!
 
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Bruno Anthony said:
Nobody has info on the f401or how it compares with the F110? On this website?! Come on now don't be shy!
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The way some sources write it it almost sounds like an F100 variant (looking at the picture above that's pretty much an F100 nozzle) but it was in the 28,000 to 30,000lb thrust class, and I'm not sure how they get there without significant changes.
 
I can post something later but effectively it had the same compressor but larger fan, bypass ducts and afterburners so a higher bypass ratio which increased thrust, especially in afterburner, and decreased SFC in cruise, at a cost in high speed performance and weight. This is quite different from the F110 which has a lower bypass ratio than the F100 I believe.
 
F401 had a larger fan, with an additional IP compressor stage attached to the rear of the fan to supercharge the compressor.
F401 F100
Entry diameter: 42in 36.5in
Overall diameter: 50.5in 47in
Bypass ratio: 1.0 0.7
Weight: 3,649lb 3,036lb
Thrust, dry: 16,400lb 14,375lb (+14%)
Thrust, AB: 28,090lb 23,810lb (+18%)
SFC, dry: 0.62 0.68
 
PaulMM (Overscan) said:
I can post something later but effectively it had the same compressor but larger fan, bypass ducts and afterburners so a higher bypass ratio which increased thrust, especially in afterburner, and decreased SFC in cruise, at a cost in high speed performance and weight. This is quite different from the F110 which has a lower bypass ratio than the F100 I believe.
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The F110 has a higher BPR than the F100
F110: 0.76 for the -129; 0.68 for the -132
F100: 0.36 for the -229
 
Thanks for the replies, fellow members. Good stuff as usual. Still somewhat of a layman at this, so my question is would the F401 have been better for F-14 performance than the GE F110?
 
It might have been great if it had worked - but the core was an uprate of the early F100, which was (to put it kindly) troubled. The engine did seem to vanish without trace after the original F-14B was chopped and the XFV-12 cratered.
 
I checked, F110 bypass ratio is similar to F100, so the F401 would probably have been a bit more economical in cruise, but less good at high speed. This would be better in some missions and worse in others. F401 would also likely have shared in the F100 issues as suggested.
 
According to the F-14D SAC of July 1985, the specs on the F110 were:
Dry weight: 4183 lbs(est.)

Inlet Diameter: 35.66 inches

Power Setting
Maximum A/B: 26,950 lbs Static Thrust at Sea Level
Intermediate: 16,333 lbs
Max. Continuous: 11,800

It appears that the F401 could have provided better Max A/B thrust at a reduced weight compared to the F110. Less weight too. How did the F401 do on the XFV-12?
 
Higher thrust in afterburner is typical of higher bypass ratio turbofans due to the additional unburnt oxygen available in the bypass air. You can chuck extra fuel in due to the greater oxygen content, giving more thust. It will come at a cost of higher afterburning SFC.

F110 would burn 20% more fuel than F401 in cruise or military power (military SFC ~0.75 versus 0.62) but less 26% less fuel in afterburner (2.01 versus ~2.55).

F110 also had a slightly lower pressure ratio than the F100/F401 (which were excessively ambitious in this regard and which contributed to their issues) but was less sensitive to disturbed airflow and perhaps more reliable.

There was no "magic" in the F401 engine configuration just a different balance of capabilities.
 
PaulMM (Overscan) said:
Higher thrust in afterburner is typical of higher bypass ratio turbofans due to the additional unburnt oxygen available in the bypass air. You can chuck extra fuel in due to the greater oxygen content, giving more thust. It will come at a cost of higher afterburning SFC.

F110 would burn 20% more fuel than F401 in cruise or military power (military SFC ~0.75 versus 0.62) but less 26% less fuel in afterburner (2.01 versus ~2.55).

F110 also had a slightly lower pressure ratio than the F100/F401 (which were excessively ambitious in this regard and which contributed to their issues) but was less sensitive to disturbed airflow and perhaps more reliable.

There was no "magic" in the F401 engine configuration just a different balance of capabilities.
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So perhaps no significant difference in Tomcat performance with either engine? Assuming the F401 came through on it's promise.
 
Steve Pace said:
wasn't this engine employed by the Rockwell XFV-12
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Yes. At the link I posted above there's a picture of that one. Looks a bit different (would need the valve for diverting air).
 
Speaking of F100, do we know the bypass ratio for the F100-PW-220? I believe the -229 is 0.36, but I can't find info on the -220.
 
This is exactly the information I've been looking for. I've been looking for the SFC for the F401 for a while. I understood it had a higher bypass ratio than the F110, and I've been wondering how that would affect the f-14's range.

Bruno Anthony said:
PaulMM (Overscan) said:
Higher thrust in afterburner is typical of higher bypass ratio turbofans due to the additional unburnt oxygen available in the bypass air. You can chuck extra fuel in due to the greater oxygen content, giving more thust. It will come at a cost of higher afterburning SFC.

F110 would burn 20% more fuel than F401 in cruise or military power (military SFC ~0.75 versus 0.62) but less 26% less fuel in afterburner (2.01 versus ~2.55).

F110 also had a slightly lower pressure ratio than the F100/F401 (which were excessively ambitious in this regard and which contributed to their issues) but was less sensitive to disturbed airflow and perhaps more reliable.

There was no "magic" in the F401 engine configuration just a different balance of capabilities.
Click to expand...

So perhaps no significant difference in Tomcat performance with either engine? Assuming the F401 came through on it's promise.
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Not in terms of thrust, but definitely yes in terms of range. It looks like the F401 would give a longer loiter time on station for CAPs, and longer range in general, but a shorter range on a supersonic deck launched intercept. So it would make the F-14 a better missileer, but it would burn through fuel faster in a dogfight or on an intercept mission.

And if you compare the F-14C (the proposed attack avionics that weren't produced) to the F-14D in the attack/strike mission, the F401 would give the F-14C longer legs. I don't know if it would be long ranged enough to replace the A-6 in the long range strike mission, but it might make an all F-14 combat element viable in a carrier air wing.

But the GE engine would be more reliable, and almost certainly allow for more carefree use throughout the flight envelope.
 
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So frustrating. For the cost of half a dozen F-14s/F-15s they could have had a fleet of Tomcats capable of fully exploiting the aerodynamics of the aircraft 15 years earlier than they did, and a fleet of F-15s and F-16s without their engines problems. Add to that the service rivalry factor, with the Air Force not willing to fund development that would help its engine and Navy threatening to cancel the project they both benefit from if the Air Force doesn't help out and - aargh.
 
what was wrong with the F401 ? anything that couldn't be solved ? rare to see a modern turbofan abandonned like this...
 
The problem was that Air Force was reportedly cooking the books on results from testing of the F100, which was the basis for the joint development program of the core, because without it they had no F-15. As a result, the Navy would have to pay a significantly higher price to get reliability of the F401 where they needed it to be. The Navy decided that was unaffordable, and decided to stay with theTF30 was never meant to be the production engine for the F-14, but at least was flying in the aircraft.
 
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F-14D said:
The problem was that Air Force was reportedly cooking the books on results from testing of the F100, which was the basis for the joint development program of the core, because without it they had no F-15. As a result, the Navy would have to pay a significantly higher price to get reliability of the F401 where they needed it to be. The Navy decided that was unaffordable, and decided to stay with theTF30 was never meant to be the production engine for the F-14, but at least was flying in the aircraft.
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AIUI, Pratt & Whitney were struggling to get the core to pass a 150-hour endurance test as normally required. The USAF, needing the engine to make the F-15 viable, decided they'd accept the engine if it could pass a 60-hour endurance test. Which it could.

Once the Air Force had accepted the engine, they (apparently successfully) argued that the 50/50 joint development agreement had been met. Any further work to meet the Navy's requirements - including the 150-hour endurance test - had to be paid solely by the Navy, which made the project unaffordable.

As well as the F-14B, there was also a study of putting an F401 into an A-7, which would have created something similar to the A-7F. Doing something similar with the F-111 seems like an obvious upgrade, though given that it was a Navy engine I doubt if it was ever really looked at.
 
The F100 was quite ambitious at the time, with a thrust/weight ratio of 8 (unprecedented for its class back then), but would end up being finicky with stalls, afterburner issues, and endurance durability. The -220 variant did solve a lot of these problems a decade later. Nevertheless, as postulated by others in the aviation community, the USAF's painful experience with the F100 was a big reason that compelled them to pursue a less technologically risky F119 for the ATF as opposed to the F120, as well as having much greater requirements for reliability.
 
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RLBH said:
F-14D said:
The problem was that Air Force was reportedly cooking the books on results from testing of the F100, which was the basis for the joint development program of the core, because without it they had no F-15. As a result, the Navy would have to pay a significantly higher price to get reliability of the F401 where they needed it to be. The Navy decided that was unaffordable, and decided to stay with theTF30 was never meant to be the production engine for the F-14, but at least was flying in the aircraft.
Click to expand...
AIUI, Pratt & Whitney were struggling to get the core to pass a 150-hour endurance test as normally required. The USAF, needing the engine to make the F-15 viable, decided they'd accept the engine if it could pass a 60-hour endurance test. Which it could.

Once the Air Force had accepted the engine, they (apparently successfully) argued that the 50/50 joint development agreement had been met. Any further work to meet the Navy's requirements - including the 150-hour endurance test - had to be paid solely by the Navy, which made the project unaffordable.

As well as the F-14B, there was also a study of putting an F401 into an A-7, which would have created something similar to the A-7F. Doing something similar with the F-111 seems like an obvious upgrade, though given that it was a Navy engine I doubt if it was ever really looked at.
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Sickening. Just sickening.
 
I get the USAF willing to accept the reduced 60 hour endurance test so they can get more F-15s in the air but why would they abandon further development? Besides for better reliability more thrust could definitely be possible later as future variants of the F100 would prove. They just didn't want (or couldn't) pay for it?
 
RLBH said:
As well as the F-14B, there was also a study of putting an F401 into an A-7, which would have created something similar to the A-7F. Doing something similar with the F-111 seems like an obvious upgrade, though given that it was a Navy engine I doubt if it was ever really looked at.
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They also looked at TF30s even more powerful than those in the F-111F but nothing ever came of them.
 
Colonial-Marine said:
I get the USAF willing to accept the reduced 60 hour endurance test so they can get more F-15s in the air but why would they abandon further development? Besides for better reliability more thrust could definitely be possible later as future variants of the F100 would prove. They just didn't want (or couldn't) pay for it?
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Given that they wound up experiencing reliability issues in service and funding the -220 engine later anyway, it probably would have made sense to continue development. Presumably a notional '-120' version could have entered service significantly earlier than 1986.

I doubt screwing the USN over was the justification for stopping work - budgets are a more likely explanation.
 
I doubt screwing the USN over was the justification for stopping work
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Don't you ever underestimate the Air Force hate for other, rival services.

In the 1950's and 1960's alone they picked successive fights with the Army twice (IRBM and ABM), the Navy (Polaris) NASA (manned spaceflight) ARPA (military spaceflight) CIA (spysats) and NRO (spysats again).

All this in the name of "space dominance" - officially, for the United States in the Cold War; unofficially, because the Air Force could see no one else getting an entire and complete monopoly over spaceflight.

But I digress...
 
RLBH said:
I doubt screwing the USN over was the justification for stopping work - budgets are a more likely explanation.
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Oh you sweet summer child. You're talking about the same service that strenuously argued that Naval Aviation should be totally disbanded after WWII. The same service that was so vehemently opposed to Naval Aviation that they managed to get an entire class of aircraft carriers canceled after the first ship had already been laid down. The same service that came within a hairsbreadth of killing all Naval Aviation in only the 3 years since they were formed and the outbreak of the Korean War. Screwing over the Navy is the main goal of the Air Force.
 
Here’s a picture of the prototype F-14B, BuNo. 157986 testing the F401, as indicated by the convergent-divergent nozzle with straight external nozzle flaps/petals (“turkey feathers”) like on the F100.

D8AA5723-C10D-49EA-8C5E-8C020F902EE5.jpeg

Here is another picture of BuNo. 157986, but based on the curved nozzle flaps, I think here it’s testing the F101DFE in the early 1980s, which became the F110.
B3462BA8-12DC-422D-8F10-8C7070923A95.jpeg
 
SSgtC said:
RLBH said:
I doubt screwing the USN over was the justification for stopping work - budgets are a more likely explanation.
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Oh you sweet summer child. You're talking about the same service that strenuously argued that Naval Aviation should be totally disbanded after WWII. The same service that was so vehemently opposed to Naval Aviation that they managed to get an entire class of aircraft carriers canceled after the first ship had already been laid down. The same service that came within a hairsbreadth of killing all Naval Aviation in only the 3 years since they were formed and the outbreak of the Korean War. Screwing over the Navy is the main goal of the Air Force.
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Could make a similar list with the space program(s)
Screwing over ARPA (military space program, 1959)
Screwing over CIA & NRO (spysats, 1963)
Screwing over the Army (THRICE: IRBM in 1957, ABM in 1965, also SAM, but they lost that one)
Screwing over NASA (manned space program)
 

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