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Author Topic: USN VFX Competition (Alternatives to the F-14)  (Read 122788 times)

Offline norseman

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Re: USN VFX Competition (Alternatives to the F-14)
« Reply #90 on: January 22, 2010, 03:00:29 pm »
With these engine problems I am even more baffled why the option on the TF41/Spey wasn't looked at further especially with 17,500/27,000lb available in this timeframe (and an option of 28,000lb reheat on customer requirements - RR option from 71). Considering the reliability record the Spey derivitives had created (not least with the A-7) would have been an interesting fit and even better fuel economy and improved servicing was on the cards from what I have read. The British Phantoms with these engines would have been very interesting indeed.

Offline TinWing

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Re: USN VFX Competition (Alternatives to the F-14)
« Reply #91 on: January 22, 2010, 07:20:24 pm »
With these engine problems I am even more baffled why the option on the TF41/Spey wasn't looked at further especially with 17,500/27,000lb available in this timeframe (and an option of 28,000lb reheat on customer requirements - RR option from 71). Considering the reliability record the Spey derivitives had created (not least with the A-7) would have been an interesting fit and even better fuel economy and improved servicing was on the cards from what I have read. The British Phantoms with these engines would have been very interesting indeed.

While the thrust levels were improved over the TF-30, the TF-41 had its own issues, both with maintenance and reliability.

Offline Mark Nankivil

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Re: USN VFX Competition (Alternatives to the F-14)
« Reply #92 on: February 12, 2010, 01:12:54 pm »
Greetings All -

A few more Model 225A related drawings from the Greater St. Louis air & Space museum archives....

Enjoy the Day! Mark

Offline F-14D

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Re: USN VFX Competition (Alternatives to the F-14)
« Reply #93 on: February 12, 2010, 01:31:54 pm »
With these engine problems I am even more baffled why the option on the TF41/Spey wasn't looked at further especially with 17,500/27,000lb available in this timeframe (and an option of 28,000lb reheat on customer requirements - RR option from 71). Considering the reliability record the Spey derivitives had created (not least with the A-7) would have been an interesting fit and even better fuel economy and improved servicing was on the cards from what I have read. The British Phantoms with these engines would have been very interesting indeed.

While the thrust levels were improved over the TF-30, the TF-41 had its own issues, both with maintenance and reliability.

The notional Advanced Technology Engine that the F-14 designed around had to meet other requirements besides just increased thrust (unrestricted throttle movement, rapid response, function at high angle of attack, improve reliability, etc.).   I doubt if the TF41/Spey could have met those, and if it couldn't what would be the point of moving to it?  Come to think of it, the F100 didn't meet those requirements until it was faced with competition from the F110.  Also, the TF41/Spey was still pretty much a "paper" engine.  The TF41 was excellent in the A-7, but that was also a much less demanding role. 

The Navy didn't have the money anyway, and if they did, they'd rather have put the money into something that would give them what the gov't originally promised.  They finally got it with the arrival of the F110. 

Also, the Navy watched what happened in the UK with the Spey on the F-4.  The Spey Phantom was a disappointment, and in retrospect many concede that doing it was a mistake, given its performance vs. its cost.  The USN probably saw no reason to spend all the money, even if they could have gotten it, on a similar experiment. 

Offline Sundog

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Re: USN VFX Competition (Alternatives to the F-14)
« Reply #94 on: February 12, 2010, 07:39:13 pm »
Until the 3 view just posted by Mark above, I had never noticed the retractable/folding canards on the Model 225A. I had thought they were a control surface, but apparently they just "extended" them to move the A.C. forward for supersonic flight, in much the same manner as the glove vane on the F-14? Has anyone seen any references to their function in the 225/225A data?

Offline PaulMM (Overscan)

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Re: USN VFX Competition (Alternatives to the F-14)
« Reply #95 on: February 12, 2010, 09:49:15 pm »
you obviously never read page 2 of this topic then :)

Relevant patent is here:

http://www.secretprojects.co.uk/forum/index.php/topic,229.msg3999.html#msg3999
"They can't see our arses for dust."
 
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Offline Sundog

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Re: USN VFX Competition (Alternatives to the F-14)
« Reply #96 on: February 12, 2010, 10:50:24 pm »
you obviously never read page 2 of this topic then :)

Relevant patent is here:

http://www.secretprojects.co.uk/forum/index.php/topic,229.msg3999.html#msg3999

Thanks, I've actually downloaded most of the pics in this thread, but I somehow missed that. Doh!

Offline AeroFranz

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Re: USN VFX Competition (Alternatives to the F-14)
« Reply #97 on: February 13, 2010, 01:49:32 pm »
Thanks to Mark for the GORGEOUS -225 drawings and cutaways. Sadly I doubt aviation manufacturers employ artists to draw like that anymore. The equivalent picture, today, would be a CAD screenshot.
All modern aircraft have four dimensions: span, length, height and politics.   TSR.2 got the first three right - Sir Sydney Camm

Offline elmayerle

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Re: USN VFX Competition (Alternatives to the F-14)
« Reply #98 on: February 13, 2010, 05:27:26 pm »
With these engine problems I am even more baffled why the option on the TF41/Spey wasn't looked at further especially with 17,500/27,000lb available in this timeframe (and an option of 28,000lb reheat on customer requirements - RR option from 71). Considering the reliability record the Spey derivitives had created (not least with the A-7) would have been an interesting fit and even better fuel economy and improved servicing was on the cards from what I have read. The British Phantoms with these engines would have been very interesting indeed.

While the thrust levels were improved over the TF-30, the TF-41 had its own issues, both with maintenance and reliability.

The notional Advanced Technology Engine that the F-14 designed around had to meet other requirements besides just increased thrust (unrestricted throttle movement, rapid response, function at high angle of attack, improve reliability, etc.).   I doubt if the TF41/Spey could have met those, and if it couldn't what would be the point of moving to it?  Come to think of it, the F100 didn't meet those requirements until it was faced with competition from the F110.  Also, the TF41/Spey was still pretty much a "paper" engine.  The TF41 was excellent in the A-7, but that was also a much less demanding role. 

The Navy didn't have the money anyway, and if they did, they'd rather have put the money into something that would give them what the gov't originally promised.  They finally got it with the arrival of the F110. 

Also, the Navy watched what happened in the UK with the Spey on the F-4.  The Spey Phantom was a disappointment, and in retrospect many concede that doing it was a mistake, given its performance vs. its cost.  The USN probably saw no reason to spend all the money, even if they could have gotten it, on a similar experiment. 
The F401 was cancelled due to a crusade led by Rep. Les Aspin to kill the F401 engine (it didn't help that just after he started this crusade two F401's came back from the test cells in bushel baskets - in one case, there was a manufacturing problem in a second-stage tubrine disk that wasn't caught; the other was a new vibratory mode that was dealt with by re-design for both the F100 and the F401)>  I have to assume, given their lack of fight for it, that the USN had lost fiath in the F401.  Mind you, Aspin's cry that'The TF30 is good enough!" was manifestly in error as was proved later in the 1970s.  Of course, when he later said, "The Navy bought a Turkey, not a Tomcat!", he did not own up to his role in neutering that Tomcat.

Offline F-14D

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Re: USN VFX Competition (Alternatives to the F-14)
« Reply #99 on: February 14, 2010, 12:11:30 am »
With these engine problems I am even more baffled why the option on the TF41/Spey wasn't looked at further especially with 17,500/27,000lb available in this timeframe (and an option of 28,000lb reheat on customer requirements - RR option from 71). Considering the reliability record the Spey derivitives had created (not least with the A-7) would have been an interesting fit and even better fuel economy and improved servicing was on the cards from what I have read. The British Phantoms with these engines would have been very interesting indeed.

While the thrust levels were improved over the TF-30, the TF-41 had its own issues, both with maintenance and reliability.

The notional Advanced Technology Engine that the F-14 designed around had to meet other requirements besides just increased thrust (unrestricted throttle movement, rapid response, function at high angle of attack, improve reliability, etc.).   I doubt if the TF41/Spey could have met those, and if it couldn't what would be the point of moving to it?  Come to think of it, the F100 didn't meet those requirements until it was faced with competition from the F110.  Also, the TF41/Spey was still pretty much a "paper" engine.  The TF41 was excellent in the A-7, but that was also a much less demanding role.  

The Navy didn't have the money anyway, and if they did, they'd rather have put the money into something that would give them what the gov't originally promised.  They finally got it with the arrival of the F110.  

Also, the Navy watched what happened in the UK with the Spey on the F-4.  The Spey Phantom was a disappointment, and in retrospect many concede that doing it was a mistake, given its performance vs. its cost.  The USN probably saw no reason to spend all the money, even if they could have gotten it, on a similar experiment.  
The F401 was cancelled due to a crusade led by Rep. Les Aspin to kill the F401 engine (it didn't help that just after he started this crusade two F401's came back from the test cells in bushel baskets - in one case, there was a manufacturing problem in a second-stage tubrine disk that wasn't caught; the other was a new vibratory mode that was dealt with by re-design for both the F100 and the F401)>  I have to assume, given their lack of fight for it, that the USN had lost fiath in the F401.  Mind you, Aspin's cry that'The TF30 is good enough!" was manifestly in error as was proved later in the 1970s.  Of course, when he later said, "The Navy bought a Turkey, not a Tomcat!", he did not own up to his role in neutering that Tomcat.

The reason the Navy lost faith was that people like the senator mentioned above were trying to kill the Tomcat, and Navy didn't want to take on a separate fight over the engine.  Since the plane would work with the TF30 (although nowhere nearly as well) they decided to marshal their strength around saving the plane and hope that later they could take care of the engine.  At that time, they didn't realize how bad the TF30 was.   A major, major additional factor was in my Sept 16, 2009 post replying to your post of earlier that same day.  I also went into this issue in greater detail here:
http://www.secretprojects.co.uk/forum/index.php/topic,4927.msg39836.html#msg39836
« Last Edit: March 28, 2010, 06:30:34 pm by F-14D »

Offline TinWing

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Re: USN VFX Competition (Alternatives to the F-14)
« Reply #100 on: February 14, 2010, 12:09:14 pm »
With these engine problems I am even more baffled why the option on the TF41/Spey wasn't looked at further especially with 17,500/27,000lb available in this timeframe (and an option of 28,000lb reheat on customer requirements - RR option from 71). Considering the reliability record the Spey derivitives had created (not least with the A-7) would have been an interesting fit and even better fuel economy and improved servicing was on the cards from what I have read. The British Phantoms with these engines would have been very interesting indeed.

While the thrust levels were improved over the TF-30, the TF-41 had its own issues, both with maintenance and reliability.

The notional Advanced Technology Engine that the F-14 designed around had to meet other requirements besides just increased thrust (unrestricted throttle movement, rapid response, function at high angle of attack, improve reliability, etc.).   I doubt if the TF41/Spey could have met those, and if it couldn't what would be the point of moving to it?  Come to think of it, the F100 didn't meet those requirements until it was faced with competition from the F110.  Also, the TF41/Spey was still pretty much a "paper" engine.  The TF41 was excellent in the A-7, but that was also a much less demanding role. 

The Navy didn't have the money anyway, and if they did, they'd rather have put the money into something that would give them what the gov't originally promised.  They finally got it with the arrival of the F110. 

Also, the Navy watched what happened in the UK with the Spey on the F-4.  The Spey Phantom was a disappointment, and in retrospect many concede that doing it was a mistake, given its performance vs. its cost.  The USN probably saw no reason to spend all the money, even if they could have gotten it, on a similar experiment. 
The F401 was cancelled due to a crusade led by Rep. Les Aspin to kill the F401 engine (it didn't help that just after he started this crusade two F401's came back from the test cells in bushel baskets - in one case, there was a manufacturing problem in a second-stage tubrine disk that wasn't caught; the other was a new vibratory mode that was dealt with by re-design for both the F100 and the F401)>  I have to assume, given their lack of fight for it, that the USN had lost fiath in the F401.  Mind you, Aspin's cry that'The TF30 is good enough!" was manifestly in error as was proved later in the 1970s.  Of course, when he later said, "The Navy bought a Turkey, not a Tomcat!", he did not own up to his role in neutering that Tomcat.

My own personal take on the F401 is that it came too late to survive the budget ax.  Despite all of its early woes, the F100 was too far along to kill, but the derivative F401 was an easy target.  Personally, I'm inclined to say that USN made a mistake by insisting on a slightly higher bypass ratio derivative of the USAF F100, despite the obvious advantages in range and loitering performance.  The F401 was just different enough from the vanilla F100 to create additional development costs, risk and delays on top of the early issues associated with the F100.  Perhaps a marinized, minimum change F100 would have survived the scrutiny Rep. Aspin?  Of course, the decreased endurance of a F100 powered F-14 might have tipped the scales against the entire program?

Of course, the real issue was the high unit cost of the F401 in comparison to the TF30.  Even the F100 was substantially more expensive than the TF30. 

Offline F-14D

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Re: USN VFX Competition (Alternatives to the F-14)
« Reply #101 on: February 14, 2010, 01:46:09 pm »
With these engine problems I am even more baffled why the option on the TF41/Spey wasn't looked at further especially with 17,500/27,000lb available in this timeframe (and an option of 28,000lb reheat on customer requirements - RR option from 71). Considering the reliability record the Spey derivitives had created (not least with the A-7) would have been an interesting fit and even better fuel economy and improved servicing was on the cards from what I have read. The British Phantoms with these engines would have been very interesting indeed.

While the thrust levels were improved over the TF-30, the TF-41 had its own issues, both with maintenance and reliability.

The notional Advanced Technology Engine that the F-14 designed around had to meet other requirements besides just increased thrust (unrestricted throttle movement, rapid response, function at high angle of attack, improve reliability, etc.).   I doubt if the TF41/Spey could have met those, and if it couldn't what would be the point of moving to it?  Come to think of it, the F100 didn't meet those requirements until it was faced with competition from the F110.  Also, the TF41/Spey was still pretty much a "paper" engine.  The TF41 was excellent in the A-7, but that was also a much less demanding role. 

The Navy didn't have the money anyway, and if they did, they'd rather have put the money into something that would give them what the gov't originally promised.  They finally got it with the arrival of the F110. 

Also, the Navy watched what happened in the UK with the Spey on the F-4.  The Spey Phantom was a disappointment, and in retrospect many concede that doing it was a mistake, given its performance vs. its cost.  The USN probably saw no reason to spend all the money, even if they could have gotten it, on a similar experiment. 
The F401 was cancelled due to a crusade led by Rep. Les Aspin to kill the F401 engine (it didn't help that just after he started this crusade two F401's came back from the test cells in bushel baskets - in one case, there was a manufacturing problem in a second-stage tubrine disk that wasn't caught; the other was a new vibratory mode that was dealt with by re-design for both the F100 and the F401)>  I have to assume, given their lack of fight for it, that the USN had lost fiath in the F401.  Mind you, Aspin's cry that'The TF30 is good enough!" was manifestly in error as was proved later in the 1970s.  Of course, when he later said, "The Navy bought a Turkey, not a Tomcat!", he did not own up to his role in neutering that Tomcat.

My own personal take on the F401 is that it came too late to survive the budget ax.  Despite all of its early woes, the F100 was too far along to kill, but the derivative F401 was an easy target.  Personally, I'm inclined to say that USN made a mistake by insisting on a slightly higher bypass ratio derivative of the USAF F100, despite the obvious advantages in range and loitering performance.  The F401 was just different enough from the vanilla F100 to create additional development costs, risk and delays on top of the early issues associated with the F100.  Perhaps a marinized, minimum change F100 would have survived the scrutiny Rep. Aspin?  Of course, the decreased endurance of a F100 powered F-14 might have tipped the scales against the entire program?

Of course, the real issue was the high unit cost of the F401 in comparison to the TF30.  Even the F100 was substantially more expensive than the TF30. 

The thing to remember is that the TF30 was never considered an adequate engine for the F-14, it was only meant to power the first 13-69 aircraft (some of which would be re-engined).  The F401 was not a derivative of the F100.  Rather, it and the F100 used the common core developed as part of the Advanced Technology Engine program, and the F100 and F401 were derivatives of that, tailored for the services' individual needs.   The F100 actually was not that much more reliable than the F401.  The thing is, the F-14 could survive without the F401, until something better came along, but the F-15 could not survive without the F100, so USAF was going to do whatever it took to insure that the latter engine survived.  Not wanting to toot my own horn too much, but also not wishing to retype (for me a major exercise), but I again refer the folks to my post http://www.secretprojects.co.uk/forum/index.php/topic,4927.msg39836.html#msg39836
which goes into detail about how USAF "adjusted" the results of F100 testing, and how USN would have been forced to foot a big bill to get a workable F401.  Remember, also, anything that hurt the F-14 was not necessarily a bad thing in USAF eyes. 

F100 was not really a worthwhile choice for USN.  Aside from not meeting the loiter, marinization (which is a complex process if not designed in from the start) and low speed thrust requirements, it only offered 1,100 lbs. more max thrust than the TF30, and its reliability was not all that good.  F100 didn't get good until years later when it was faced with competition from the F110.  So, it didn't make sense for USN, if it couldn't get F401, to spend a boatload of money and risk the whole F-14 program on an engine that wouldn't do that much for them. 


Offline Mark Nankivil

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Re: USN VFX Competition (Alternatives to the F-14)
« Reply #102 on: March 09, 2010, 06:39:08 am »
Greetings All -

Here's the SAC for the Model 225A pulled from the Performance volume of the proposal. 

Enjoy the Day! Mark

Offline AeroFranz

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Re: USN VFX Competition (Alternatives to the F-14)
« Reply #103 on: March 09, 2010, 09:00:01 am »
nice present  ;) Thanks!
All modern aircraft have four dimensions: span, length, height and politics.   TSR.2 got the first three right - Sir Sydney Camm

Offline Machdiamond

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Re: USN VFX Competition (Alternatives to the F-14)
« Reply #104 on: March 09, 2010, 09:31:54 am »
Ooooh yes Mark, that is the kind of document that I really like  :)
Many thanks,
--Luc