Discussion: F-14, F-15 Hybrid Idea

[KJ_Lesnick]

Mr. Mayerle,

I'm not sure how the breakdown between GD and Convair on work went as some aircraft produced at the Fort Worth facility are clearly labelled Convair while others are GD; I think Convair ended up being more the San Diego side of things.  I don't know about political lobbying, but I do have the feeling that NAA-Los Angeles and NAA-Columbus operated rather independently a lot of the time, going on appearances.  Grumman proper may have been in NY, but I'll wager they had a supplier network all over the country.

Understood.  

I just remember hearing that one of the reasons the F-14 didn't get refitted with the F-401, F-100 or F-110 and ended up stuck with the TF-30 for 13 years of it's service was because of Grumman's inability to lobby Congress.


KJ Lesnick

[elmayerle]

Actually, the F-14 didn't get the F401 because a Representative spearheaded an effort to kill the F401, which, admittedly, was having some development troubles at the time, on the grounds that the "TF30 is 'good enough'!"  This same representative, some four-five years later, when proplems with the TF30 were causing no end of grief for the F-14, gave the opinion that "The Navy bought a Turkey, not a Tomcat!" and totally ignored his part in hte debacle.  This "gentleman" later went on to become Pres. Clinton's first SecDef, Les Aspin.

It was only when the evidence mounted sufficiently high for even Congress to notice that development of the F101DFE/F110 was initiated.  It could be argued that in cancelling the F401 and not, at least, proceding with an afterburning TF$! as an alternative to the TF30, Congress was rather remiss and, thus, certainly bears a significant portion of the blame for the deaths the continued use of the TF30 caused.  Now, using the F100 would've been a bit problematical in that, despite sharing a common core with the F401, it was a slightly smaller engine and not as powerful; additionally, it had its own raft of development problems to resolve.

Note, if anyone wonders why I remember something from 30+ years ago so well, I was working for P&W on the F100/F401 when the F401 was cancelled (I agree, they'd had problems, bringing two engines in a row back from the test stand in bushel baskets is not good, but they found and fixed the problems) and that cancellation led to my being laid off from there; I was unemployed for nine months and the events were impressed on my memory as was a desire to monitor later related events.  Am I a bit bitter?  Well, I've mellowed with time, but my opinion of the "honorable" Mr. Aspin has not changed since he never, to the best of my knowledge, ever admitted any part in the F-14's problems with the TF30.

[Taiidantomcat]

Actually, the F-14 didn't get the F401 because a Representative spearheaded an effort to kill the F401, which, admittedly, was having some development troubles at the time, on the grounds that the "TF30 is 'good enough'!"  This same representative, some four-five years later, when proplems with the TF30 were causing no end of grief for the F-14, gave the opinion that "The Navy bought a Turkey, not a Tomcat!" and totally ignored his part in hte debacle.  This "gentleman" later went on to become Pres. Clinton's first SecDef, Les Aspin.

That explains it.

[KJ_Lesnick]

Mr. Mayerle,

Actually, the F-14 didn't get the F401 because a Representative spearheaded an effort to kill the F401, which, admittedly, was having some development troubles at the time, on the grounds that the "TF30 is 'good enough'!"

Was there any other reason other than the development troubles with the F-401 that Les Aspin made it his mission to destroy it?

This same representative, some four-five years later, when proplems with the TF30 were causing no end of grief for the F-14, gave the opinion that "The Navy bought a Turkey, not a Tomcat!" and totally ignored his part in hte debacle.

That is just so wrong...

This "gentleman" later went on to become Pres. Clinton's first SecDef, Les Aspin.

I've heard of him, but honestly I never really knew all that much about him.  The only thing I really knew was that he was the guy that allowed female pilots to fly combat-missions.

It was only when the evidence mounted sufficiently high for even Congress to notice that development of the F101DFE/F110 was initiated.  It could be argued that in cancelling the F401 and not, at least, proceding with an afterburning TF$! as an alternative to the TF30, Congress was rather remiss and, thus, certainly bears a significant portion of the blame for the deaths the continued use of the TF30 caused.  Now, using the F100 would've been a bit problematical in that, despite sharing a common core with the F401, it was a slightly smaller engine and not as powerful; additionally, it had its own raft of development problems to resolve.

The F-100 was less powerful than the F-401 but it was more powerful than the TF-30 right (or did I misunderstand what you said)?

Note, if anyone wonders why I remember something from 30+ years ago so well, I was working for P&W on the F100/F401 when the F401 was cancelled (I agree, they'd had problems, bringing two engines in a row back from the test stand in bushel baskets is not good, but they found and fixed the problems) and that cancellation led to my being laid off from there; I was unemployed for nine months and the events were impressed on my memory as was a desire to monitor later related events.  Am I a bit bitter?  Well, I've mellowed with time, but my opinion of the "honorable" Mr. Aspin has not changed since he never, to the best of my knowledge, ever admitted any part in the F-14's problems with the TF30.

Well, it would definitely explain a lot, though I think you mentioned before though that you worked on the F-401 program.  Regardless, I wouldn't blame you for being pissed off at Mr. Aspin over the whole issue.  At least on the bright side, Aspin died in 1995 (I just checked on wikipedia)


K.J. Lesnick

[elmayerle]

I think Mr. Aspin was trying to follow in the footsteps of his somewhat-mentor, Sen. William Proxmire, in going after "wasteful spending" and I suspect the cost of the F401, when the F-14 was already flying with the TF30, probably attracted him in combination with the development problems the F401 had (though the F401 testing did help hasten the development of the F100 since a lot of data could be read across).  The F100 was indeed more powerful than the TF30, at least variants flying then (final development for late-model F-111s was a bit more powerful than the original F100), but definitely less powerful than the F401.

[KJ_Lesnick]

Mr. Mayerle

I think Mr. Aspin was trying to follow in the footsteps of his somewhat-mentor, Sen. William Proxmire, in going after "wasteful spending" and I suspect the cost of the F401, when the F-14 was already flying with the TF30, probably attracted him in combination with the development problems the F401 had (though the F401 testing did help hasten the development of the F100 since a lot of data could be read across).

Okay that makes sense (Proximire)...

Still, the F-14 needed a new engine, and the TF-30 wasn't cutting it; that's not wasteful spending...

The F100 was indeed more powerful than the TF30, at least variants flying then (final development for late-model F-111s was a bit more powerful than the original F100), but definitely less powerful than the F401.

Were the later F-100's more powerful than the late-model F-111's TF-30's?


KJ Lesnick

[elmayerle]

Yes, the late-model F100s have higher ratings than the late-model TF30s.  The current productin F100-PW-229 has an aftrburning thrust of 29,000 lbt. and they've tested and proven a F100-PW-232 that matches the performance of the F110-GE-232 engines installed in the F-16E/F family for the UAE.

The thing is, when the F401 was cancelled, Aspin had based his opposition to it on the grounds that the TF30 was "good enough" and I can't see him then backtracking and funding another engine.  Whether the F401 deserved to be cancelled with its development problems as well as the problems found with the similar early F100 is another question, but even if those problems merited cancelling that engine, something like an afterburning TF41 (which an Allison-RR team had demonstrated in testbeds back in 1967) should've been put forward as an alternate engine.

[KJ_Lesnick]

Would the F-100 have been a better choice than the TF-30?  It sounds like it would be cheaper than the F-401 and yet more powerful than the TF-30 and the design was already being used on another military plane (At least by 1972, the F-15)/ 


KJ Lesnick

[elmayerle]

Would the F-100 have been a better choice than the TF-30?  It sounds like it would be cheaper than the F-401 and yet more powerful than the TF-30 and the design was already being used on another military plane (At least by 1972, the F-15)/ 

Well, the F100 wasn't that much cheaper than the F401 (they were quite close siblings, both derived from PWA's JTF-22 demonstration engine and sharing considerable commonality, esp. in the high-pressure compressor, combustor, high-pressure turbhine "core", with the differences being mainly in the low-presure section with a slightly higher bypass-ratio for the F401 which also made the afterburners and nozzles different but of similar design.  The fixes for the problems that led to the lsst couple F401s tested being brought back in bushel baskets were read right across to the F100

[KJ_Lesnick]

Mr. Mayerle,

How much more expensive was the F401 (like 10%, 20% more, etc), assuming it's not classified or anything?

Considering the F401 had a different LP set-up (I take it it had to do with the different fan and an aim for a higher pressure-ratio?) and a higher-bypass ratio than the F100:  How much of a difference was there in terms of fuel-consumption, and top speed?  (I'm asking this as the WHIF I was aiming for was to have a top-speed more like the F-15 and the F-15 was somewhat faster than the F-14 -- I know airframe and inlets play a huge role, but higher bypass-ratios generally do penalize you in the high-speed range)


B.T.W.
- The F401 had problems with it's LP compressor right?
- Did Les Aspin go after any other "wasteful spending" projects?  Or just the F401?


K.J. Lesnick

[elmayerle]

Mr. Mayerle,

How much more expensive was the F401 (like 10%, 20% more, etc), assuming it's not classified or anything?

Considering the F401 had a different LP set-up (I take it it had to do with the different fan and an aim for a higher pressure-ratio?) and a higher-bypass ratio than the F100:  How much of a difference was there in terms of fuel-consumption, and top speed?  (I'm asking this as the WHIF I was aiming for was to have a top-speed more like the F-15 and the F-15 was somewhat faster than the F-14 -- I know airframe and inlets play a huge role, but higher bypass-ratios generally do penalize you in the high-speed range)


B.T.W.
- The F401 had problems with it's LP compressor right?
- Did Les Aspin go after any other "wasteful spending" projects?  Or just the F401?

I honestly don't know about the price differences between the F401 and F100, but I wouldn't expect too great a differential given how similar they were.  Yes, the F401 had a different fan/l-p compressor section which was matched by a different l-p turbine section, but the bypass ratio wasn't significantly greater as, if memory serves me correctly, the F401 was only a couple more inches greater in diameter than the F100.  I can't prove it, but I suspect the F-14 with the F401 would've been a match, speed-wise, for the F-15 since the inlets were designed for the F401's mass flow, not the TF30's (I suspect the F-14A had some rescheduling of the inlets for the engine it was stuck with).  I doubt fuel comsumption was much greater than the F100, though I'm not sure, after 30+ years, of the exact numbers.  The main problems I remember the F401 having (at least that trashed the last two test articles) were in the l-p turbine (in one case it was a manufacturing oopsie that didn't get caught and in the other they found a rssonant frequency for the spacer 'tween that 3rd and 4th stage turbine disks - the first would've been dealt with by retraining and inspection and the second was dealt with by a design change - but fixes reading across to the F100 development effort).

Regarding Les Aspin, I don't know, personally, of too many other "wasteful spending" projects he went after save as the House counterpart of Sen. Proxmire (save, of course, the later comment regarding the F-14 that I mentioned earlier).

[Taiidantomcat]

Mr. Mayerle,

How much more expensive was the F401 (like 10%, 20% more, etc), assuming it's not classified or anything?

Considering the F401 had a different LP set-up (I take it it had to do with the different fan and an aim for a higher pressure-ratio?) and a higher-bypass ratio than the F100:  How much of a difference was there in terms of fuel-consumption, and top speed?  (I'm asking this as the WHIF I was aiming for was to have a top-speed more like the F-15 and the F-15 was somewhat faster than the F-14 -- I know airframe and inlets play a huge role, but higher bypass-ratios generally do penalize you in the high-speed range)


B.T.W.
- The F401 had problems with it's LP compressor right?
- Did Les Aspin go after any other "wasteful spending" projects?  Or just the F401?

Regarding Les Aspin, I don't know, personally, of too many other "wasteful spending" projects he went after save as the House counterpart of Sen. Proxmire (save, of course, the later comment regarding the F-14 that I mentioned earlier).

A Lot of politicians love to make their name and reputation killing military programs... IMHO anything would have been better than a TF-30. Of the many Tomcats lost almost all of them could be traced back to TF-30 problems. The fact that we had to armor plate our engine housing for when (not if, but when) they exploded should have been a massive red flag as to how bad the TF-30 was. This is one of the richest countries in the world and we fit the Navy's fleet defender with engines that BLOW UP. It was a bad decision and it killed people. and like a lot of "self fulfilling" political prophecies he makes it look like the military is incompetent with the pathetic equipment some politician has thrust on them.

[KJ_Lesnick]

Mr. Mayerle,

I honestly don't know about the price differences between the F401 and F100, but I wouldn't expect too great a differential given how similar they were.

Sounds like a good enough point.

Yes, the F401 had a different fan/l-p compressor section which was matched by a different l-p turbine section, but the bypass ratio wasn't significantly greater as, if memory serves me correctly, the F401 was only a couple more inches greater in diameter than the F100.

So, the bypass was like 0.80 to 0.90 to 1 instead of 0.7 : 1?

I doubt fuel comsumption was much greater than the F100, though I'm not sure, after 30+ years, of the exact numbers.

It's fuel consumption would be greater?  How?  If you have a higher bypass ratio and the same core wouldn't you have a lower fuel consumption? 

The main problems I remember the F401 having (at least that trashed the last two test articles) were in the l-p turbine (in one case it was a manufacturing oopsie that didn't get caught and in the other they found a rssonant frequency for the spacer 'tween that 3rd and 4th stage turbine disks - the first would've been dealt with by retraining and inspection and the second was dealt with by a design change - but fixes reading across to the F100 development effort).

Regarding the F100, these problems would have manifested on the F100 too, and the F401's mistakes helped the F100?

What kind of manufacturing mistake?  Like they didn't lock the blade in right or something?  I take it there was no way to have spotted the resonant-frequency problem before hand, reasonably speaking? 

Regarding Les Aspin, I don't know, personally, of too many other "wasteful spending" projects he went after save as the House counterpart of Sen. Proxmire (save, of course, the later comment regarding the F-14 that I mentioned earlier).

So he pretty much singled the TF-30 out, and he went after like 3 or 4 other things (to look "cool" like Senator Proxmire) from what it sounds like?


Taiidantomcat,

A Lot of politicians love to make their name and reputation killing military programs...

Well, truthfully speaking there are some programs that really shouldn't keep going for one reason or another, but there are some programs that really should not be cancelled.

IMHO anything would have been better than a TF-30. Of the many Tomcats lost almost all of them could be traced back to TF-30 problems.

The TF-30 was a disaster in a number of ways, which is quite surprizing as Pratt & Whitney generally made good engines. 

The fact that we had to armor plate our engine housing for when (not if, but when) they exploded should have been a massive red flag as to how bad the TF-30 was.

Yeah, you would have thought it was an engine built by the former Soviets (their engines were often very problematic from what I remember). 

This is one of the richest countries in the world and we fit the Navy's fleet defender with engines that BLOW UP. It was a bad decision and it killed people. and like a lot of "self fulfilling" political prophecies he makes it look like the military is incompetent with the pathetic equipment some politician has thrust on them.

I would have to agree with you in this particular case.


KJ Lesnick

[Sauragnmon]

And this is one of those moments where the Americans could have benefitted from a Russian addage... "Better is the enemy of Good Enough"  Or my own personal line of choice - Its not Overkill... it's Insurance.

The TF-30 was an interrim choice of engines, and it took that infamous, colourful pilot explaining it to the government to remind them exactly WHY it was an interrim choice.

[KJ_Lesnick]

Sauragnmon,

And this is one of those moments where the Americans could have benefitted from a Russian addage... "Better is the enemy of Good Enough"  Or my own personal line of choice - Its not Overkill... it's Insurance.

Actually, the TF-30 was not even good enough.  It was a substandard engine for the plane and the mission it was designed to perform in the F-14. 

The TF-30 was an interrim choice of engines, and it took that infamous, colourful pilot explaining it to the government to remind them exactly WHY it was an interrim choice.

What pilot said that?  Are you talking about VADM Tom Connolly?  If so, he was predominantly criticizing the F-111B claiming that there wasn't enough thrust in Christendom to make a good fighter out of the F-111, not that the TF-30 wasn't an interim choice...


KJ Lesnick