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Old 08-01-2020, 10:30 PM   #21
Victory205
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Originally Posted by LanceCriminal86 View Post
I too have seen some references to Mil power catshots for As, and I'm wondering if the increasing weight of the A models maybe had to do with it? It may also have to do with the weight at launch and the loadout of the jet.
Almost all of those mil power shots were during CQ, with the aircraft less than fully fueled, with little or no ordnance. Essentially, it's gross weight, wind and temp conditions.
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“Imo im glad he is gone. He was a really mean, narcissistic and disrespectfull person. Everyone has to cheer him that hecwas a real tomcat driver and only his way is the best way. And when you question him or want to discuss stuff like "shutdown hud for landing" he get angry and offensive very fast. Im glad he is gone...”
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Old 08-01-2020, 11:52 PM   #22
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I've heard this and I can find no source other than people saying "I heard they were de-tuned." Here's the thing: the Preliminary Technical Order from June 1972 indicates an installed thrust of the TF-30P-412 (0 altitude, 0 airspeed) as 10,500lbs at military power and 17,000 pounds in max afterburner. Later NATOPS manuals refined the numbers for the -414/414A; the 1981, 1984, 1995 and 2004 manuals all show 10,875lbs military and 17,077lbs in max afterburner installed thrust (again at 0 altitude and 0 airspeed). That tells me the engine wasn't de-tuned. The aircraft did get heavier, though, so the thrust-to-weight ratio got worse on account of the jet itself, not the motors.
I'll try and find the sources (if they are still around - changed a few HDD's since) and see if there were any changes and if so how much. Might not even be the installed thrust that's changed, but the dynamic one available throughout different parts of the envelope. As i said though, not sure

Edit: i have no idea how reliable this source is, but found it after a quick google:

https://www.thisdayinaviation.com/tag/pratt-whitney-tf30-p-412/


EDIT 2: scratch that, irrelevant

EDIT 3: i think i found it. F-14 Aircraft and propulsion control integration evaluation. Pages 4 and 5. Look under FADEC control.



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"Rapid, Unplanned, Disassembly."

Last edited by captain_dalan; 08-02-2020 at 12:45 AM.
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Old 08-02-2020, 01:31 AM   #23
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Originally Posted by captain_dalan View Post
I'll try and find the sources (if they are still around - changed a few HDD's since) and see if there were any changes and if so how much. Might not even be the installed thrust that's changed, but the dynamic one available throughout different parts of the envelope. As i said though, not sure
EDIT 3: i think i found it. F-14 Aircraft and propulsion control integration evaluation. Pages 4 and 5. Look under FADEC control.
Reading that document, it's about a test proposal of how a FADEC could benefit the TF-30P-414 engine's stability. It talks about AICS (ramp) scheduling, the benefits of a FADEC, and proposed testing. Pages 4-5 focus on what a FADEC could help with, and indicate an improvement to thrust, not a loss. As it stands, the TF-30 never got a FADEC, so it doesn't seem relevant to me.

That said, maybe there was a change at some point, maybe the engine doesn't make as much thrust at a given airspeed and altitude in an attempt to improve stability; I know the AICS was reprogrammed and implemented in 1976, but frankly have no idea how much of an impact that would have had, and that's specific to the ramps scheduling, not the engine. BUT! That's just a maybe; the documentation I've seen so far points to the contrary.

Last edited by Quid; 08-02-2020 at 01:34 AM. Reason: Grammar
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Old 08-02-2020, 12:34 PM   #24
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Originally Posted by WolfHound009 View Post
I have a question, Did -A Cats always need Zone 5 A/B when taking off from carriers? I was watching a F-14 Documentary recently which had footage from VF-1 and Vf-2s first cruise and some of the -A Tomcats in that footage didn't appear to be using afterburner as there were no bright exhausts. What could be the reason for this ?
The F-14 as a result of the A's poor engine reliability was not allowed under normal operations to use it's afterburner on take off. The less needed fuel flow meant a flame out became less likely and it meant if it did happen as it has happened even on Mil power meant pilots if reacting quick enough had a much better change to counter act the A-symmetric thrust and save the aircraft.

Of course with some movies ect particularly in the Final Countdown and TOPGUN cinema era as these films were a good recruiting tool the Navy tended to allow full AB take offs for pictures or movies but it is technically a prohibited action during the the Tomcat's USN service.

Once the engines were switched to the F110 this rule became more or less redundant but was kept in the manuals/procedures for the F-14B and F-14D.
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Old 08-02-2020, 12:57 PM   #25
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Originally Posted by Quid View Post
Reading that document, it's about a test proposal of how a FADEC could benefit the TF-30P-414 engine's stability. It talks about AICS (ramp) scheduling, the benefits of a FADEC, and proposed testing. Pages 4-5 focus on what a FADEC could help with, and indicate an improvement to thrust, not a loss. As it stands, the TF-30 never got a FADEC, so it doesn't seem relevant to me.

That said, maybe there was a change at some point, maybe the engine doesn't make as much thrust at a given airspeed and altitude in an attempt to improve stability; I know the AICS was reprogrammed and implemented in 1976, but frankly have no idea how much of an impact that would have had, and that's specific to the ramps scheduling, not the engine. BUT! That's just a maybe; the documentation I've seen so far points to the contrary.
The way a read it, it limits the air available to the engine under certain conditions, so reducing thrust but increasing compressor stall resistance. But if it was never implemented.......
Odd, i guess more digging is in order.
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Old 08-02-2020, 01:01 PM   #26
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Originally Posted by Southernbear View Post
The F-14 as a result of the A's poor engine reliability was not allowed under normal operations to use it's afterburner on take off. The less needed fuel flow meant a flame out became less likely and it meant if it did happen as it has happened even on Mil power meant pilots if reacting quick enough had a much better change to counter act the A-symmetric thrust and save the aircraft.

Of course with some movies ect particularly in the Final Countdown and TOPGUN cinema era as these films were a good recruiting tool the Navy tended to allow full AB take offs for pictures or movies but it is technically a prohibited action during the the Tomcat's USN service.

Once the engines were switched to the F110 this rule became more or less redundant but was kept in the manuals/procedures for the F-14B and F-14D.
Sorry but this is completely erroneous: A models could cat launch in military power if lightly loaded as victory205 alludes to above. Otherwise afterburner was an absolute requirement.

The B and D were the models forbidden to cat launch in burner as there was so much thrust if they lost an engine on the cat stroke that the asymmetric thrust from the remaining good engine would be too powerful for the control surfaces to overcome at the low airspeed and high AOA conditions encountered one clear of the cat.
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Old 08-08-2020, 03:20 AM   #27
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Originally Posted by Quid View Post
Reading that document, it's about a test proposal of how a FADEC could benefit the TF-30P-414 engine's stability. It talks about AICS (ramp) scheduling, the benefits of a FADEC, and proposed testing. Pages 4-5 focus on what a FADEC could help with, and indicate an improvement to thrust, not a loss. As it stands, the TF-30 never got a FADEC, so it doesn't seem relevant to me.

That said, maybe there was a change at some point, maybe the engine doesn't make as much thrust at a given airspeed and altitude in an attempt to improve stability; I know the AICS was reprogrammed and implemented in 1976, but frankly have no idea how much of an impact that would have had, and that's specific to the ramps scheduling, not the engine. BUT! That's just a maybe; the documentation I've seen so far points to the contrary.
No luck. Went through my entire archive (well, what's left of it) and found nothing further on the topic. So it's either no longer there and lost to time, or (most likely) i must have read it in some interview or some such .
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