How to hit Mach 2.4?

[DD_Fenrir]

14 hours ago, Hawkeye91 said:

Interesting. I did not know the TF30s were derated in our version in DCS. Do you know by how much exactly?

Here ya go:

Timestamp is: 1:00:47.

Each engine de-rated from 20,00lb to 17,000lb for total of 6,000lb less.

Edited June 17, 2022 by DD_Fenrir

[Ala12Rv-Tundra]

1 hour ago, DD_Fenrir said:

Here ya go:

Timestamp is: 1:00:47.

Each engine de-rated from 20,00lb to 17,000lb for total of 6,000lb less.

 

Didn't know this fact, thanks

[WelshZeCorgi]

I just tried with the B, couldn't get past 2.1 at 40k feet. Completely clean. 

[DD_Fenrir]

Yes. Cos whilst the F110 has much greater static thrust than the TF30, once the aircraft is at high speed the design of the PW engine benefits more from ram-air effects; under those circumstances (high alt/high speed) the TF30 actually develops the greater thrust.

[Katj]

Here ya go:
Timestamp is: 1:00:47.
Each engine de-rated from 20,00lb to 17,000lb for total of 6,000lb less.

Honestly, I think this is just a misunderstanding of the difference between the static thrust and installed thrust.

Also, early A models were delivered with TF30-P-412A engines and later with TF30-P-414A engines. I don't know the difference.

Apparently at least one jet was fitted with TF30-P-7 engines, and that jet was reported to have been a real hot-rod, flying about as fast in zone 2 as another jet in zone 5. I can find the source for this if there is interest.

[WelshZeCorgi]

42 minutes ago, DD_Fenrir said:

Yes. Cos whilst the F110 has much greater static thrust than the TF30, once the aircraft is at high speed the design of the PW engine benefits more from ram-air effects; under those circumstances (high alt/high speed) the TF30 actually develops the greater thrust.

So neither A or B that we get in DCS is able to reach the stated 2.34 Mach? Wonder what all the other people saying they got to Mach 2.5-2.6 are talking about then. 

[Bremspropeller]

42 minutes ago, DD_Fenrir said:

once the aircraft is at high speed the design of the PW engine benefits more from ram-air effects; under those circumstances (high alt/high speed) the TF30 actually develops the greater thrust

I think it's mostly down to the fact that they didn't bother to change the intake area and ramp-schedule to tweak for max performance of the F110. That's probably what everyone means when they're talking "ram-effects".

 

[Spurts]

37 minutes ago, WelshZeCorgi said:

So neither A or B that we get in DCS is able to reach the stated 2.34 Mach? Wonder what all the other people saying they got to Mach 2.5-2.6 are talking about then. 

You should understand because you even posted about it.  It's the squadron hotrod.  Not all planes run the same.  When I was in the Army my company had a fleet of HMMWV ambulances.  Mine was the pig that couldn't get past 30mph unless I was going downhill.  Another guy had "the Ferrari" that would hit 55mph no problem and also turned tighter than any other HMMWV we had.  Despite being made by the same company in the same year and getting the "same" maintenance neither is representative of a standard M997.

I say "same" maintenance because I did better operator level maintenance than anyone else in my unit.  When I had to PMCS "the Ferrari" I found that it one of the front wheels had been grinding through a tie rod from those tighter turns.  The guy who was responsible for that vehicle had no idea.

Our DCS Tomcat, A or B, needs to be representative of a standard fleet Tomcat, not a unit hotrod, and not a unit dog.  It has to match the charts, not pilot reports of flying the hotrod on a cold day for a MFCF.

 

44 minutes ago, Bremspropeller said:

I think it's mostly down to the fact that they didn't bother to change the intake area and ramp-schedule to tweak for max performance of the F110. That's probably what everyone means when they're talking "ram-effects".

 

that is part of it, but the TF30 was also an open loop system.  More air = more fuel burned = more thrust.  This is the same effect that allowed the MiG-25 to hit Mach 3.2.  It open-looped itself into the record books as the engine cooked itself and never flew again.  The F110 had FADEC that did not allow runaway thrust.  It would limit itself to not exceed a designated condition.

[WelshZeCorgi]

7 minutes ago, Spurts said:

You should understand because you even posted about it.  It's the squadron hotrod.  Not all planes run the same.  When I was in the Army my company had a fleet of HMMWV ambulances.  Mine was the pig that couldn't get past 30mph unless I was going downhill.  Another guy had "the Ferrari" that would hit 55mph no problem and also turned tighter than any other HMMWV we had.  Despite being made by the same company in the same year and getting the "same" maintenance neither is representative of a standard M997.

I say "same" maintenance because I did better operator level maintenance than anyone else in my unit.  When I had to PMCS "the Ferrari" I found that it one of the front wheels had been grinding through a tie rod from those tighter turns.  The guy who was responsible for that vehicle had no idea.

Our DCS Tomcat, A or B, needs to be representative of a standard fleet Tomcat, not a unit hotrod, and not a unit dog.  It has to match the charts, not pilot reports of flying the hotrod on a cold day for a MFCF.

 

that is part of it, but the TF30 was also an open loop system.  More air = more fuel burned = more thrust.  This is the same effect that allowed the MiG-25 to hit Mach 3.2.  It open-looped itself into the record books as the engine cooked itself and never flew again.  The F110 had FADEC that did not allow runaway thrust.  It would limit itself to not exceed a designated condition.

I'm talking about the people who said they got the DCS f14 up to that speed. 

[DD_Fenrir]

4 minutes ago, WelshZeCorgi said:

I'm talking about the people who said they got the DCS f14 up to that speed. 

Question 1: When? The development of the DCS: Tomcat module is still in progress and Heatblur are still fine tuning some of the performance parameters. Ergo, some legacy patches may have given artificially improved performance.

Question 2: What atmospheric pressure? Map and weather will define performance as air density significantly effects thrust as greater pressure = greater air density = more oxygen molecules to burn in a given cubic measure of air, whatever the altitude.

[WelshZeCorgi]

7 hours ago, Panny said:

yup, think fastest I achieved was M2.42. Launched with bags, tanked, got to altitude, accelerated to around M1.7 by the time bags were empty, jettisoned them and continued to push aircraft while around 36k feet

 

[LanceCriminal86]

1 hour ago, Katj said:

Honestly, I think this is just a misunderstanding of the difference between the static thrust and installed thrust.

Also, early A models were delivered with TF30-P-412A engines and later with TF30-P-414A engines. I don't know the difference.

Apparently at least one jet was fitted with TF30-P-7 engines, and that jet was reported to have been a real hot-rod, flying about as fast in zone 2 as another jet in zone 5. I can find the source for this if there is interest.

I recall that story, I think it was a DS or Southern Watch TARPS run and the TARPS jet just straight walked away from their "escort" Tomcat. I think they stated they had always wondered why and it turned out it had the compressor section from the F-111 variant or something along those lines.

All ties into what Victory205 and others reiterated during the great FM chart wars, is that every jet was different in some way. While they would fly about the same some airframes, engines, etc. performed slightly different. I'd love to see some of that modeled, have % baked in to available thrust, turn rates, fuel economy, likelihood of system failures.

 

[WelshZeCorgi]

1 hour ago, LanceCriminal86 said:

I recall that story, I think it was a DS or Southern Watch TARPS run and the TARPS jet just straight walked away from their "escort" Tomcat. I think they stated they had always wondered why and it turned out it had the compressor section from the F-111 variant or something along those lines.

All ties into what Victory205 and others reiterated during the great FM chart wars, is that every jet was different in some way. While they would fly about the same some airframes, engines, etc. performed slightly different. I'd love to see some of that modeled, have % baked in to available thrust, turn rates, fuel economy, likelihood of system failures.

 

I agree, would be interesting and unique, but we both know this would never happen. A lot of people would disagree with us. Most people would pick up pitchfork if they lost a dogfight and blamed the 0.2% difference in performance between 2 similar airframes, or crashed because they had a engine issue and either ignored it or didn't know what to do. 

Edited June 17, 2022 by WelshZeCorgi

[Spurts]

4 hours ago, WelshZeCorgi said:

I agree, would be interesting and unique, but we both know this would never happen. A lot of people would disagree with us. Most people would pick up pitchfork if they lost a dogfight and blamed the 0.2% difference in performance between 2 similar airframes, or crashed because they had a engine issue and either ignored it or didn't know what to do. 

 

You are right about that

[Exorcet]

4 hours ago, WelshZeCorgi said:

I agree, would be interesting and unique, but we both know this would never happen. A lot of people would disagree with us. Most people would pick up pitchfork if they lost a dogfight and blamed the 0.2% difference in performance between 2 similar airframes, or crashed because they had a engine issue and either ignored it or didn't know what to do. 

 

It's an easy problem to fix. Random failures already exist, they just need to be turned on. The same should be true for randomly variable airframes.

[r4y30n]

I think it's mostly down to the fact that they didn't bother to change the intake area and ramp-schedule to tweak for max performance of the F110. That's probably what everyone means when they're talking "ram-effects".
 

Hard to imagine they were that lazy after the rather complete feasibility study done for the F110 proposal. Look up “F-14 Re-Engining with the F110 Engine.”


In regards to inlet testing:
“The test aircraft had complete dynamic and steady state pressure inlet rake data available which allowed accumulation of extensive distortion data.”

[WelshZeCorgi]

3 hours ago, Exorcet said:

It's an easy problem to fix. Random failures already exist, they just need to be turned on. The same should be true for randomly variable airframes.

Then the next hurdle would be convincing HB or ED to implement it. They'd be even less inclined to do so if it would be a tonne of work to implement, only for it to become an option they thought 1% of their community would use. 

[KL0083]

https://youtu.be/2GxsHT5sygw

To have some taste with this issue last night,reminds me of the experience on FSX and surprisingly the engine was not stall with gunshot.

[Panny]

This is a quick and rough Tacview I did this morning. Sustained M2.31 in the F-14A. Considering no glove vanes, TCS, sidewinder rails, and tank stubs, this is pretty good, this is pretty damn close to the stated max 2.34 Grumman advertises. Also in a small dive got to M2.33. Only ejected tanks when approx. M1.8.

Mission was tested on Marianas on default weather settings.

Tacview-20220618-091413-DCS-Drag Race.zip.acmi

[Bremspropeller]

11 hours ago, r4y30n said:

Hard to imagine they were that lazy after the rather complete feasibility study done for the F110 proposal. Look up “F-14 Re-Engining with the F110 Engine.”

It's more a matter of ca$h than laziness. If the resulting airplane does rather well across the board and only has some isolated spots of lower (or negative) performance gain in places that are of secondary concern for normal missions, that's something you'd gladly accept.

[captain_dalan]

Tacview-20220618-201511-DCS-F-14 A high level clean EVAL.zip.acmi Tacview-20220618-202352-DCS-F-14 B high level clean EVAL.zip.acmi Tacview-20220618-203355-DCS-F-14 A high level clean EVAL no pylons on A.zip.acmi

On 6/16/2022 at 1:55 PM, QuiGon said:

Should get even faster if you remove the pylons for less drag and fly higher.

Removing the pylons is a purely cosmetic act in DCS on the F-14. 
The test starting conditions:
-36000ft;
-mach 0.75;
-full internal fuel no external stores;

Both A and B were tested. The A was tested with and without what the mission editor call pylons but are actually IIRC Phoenix palettes. Neither the plane mass/weight nor its drag changes due to their presence or absence. In both scenarios the A reached mach 2.31 under standard conditions until reaching the bingo state of 4000lbs. The B got to about mach 2.14.

My guess is that the palettes in the F-14 are either always present or added to the missiles when those are mounted. Both drag and mass wise. 

As for the OP, if mach 2.31 is what we can reach with the shoulder pylons on and with tank stubs, then (palettes or not) i can easily see how a completely clean F-14A could get up to mach 2.34 or possibly even more.

One question still stands though....... are the palettes always added to the plane, or are they added to the missiles? 

EDIT: screenshots and tacview files attached

Edited June 18, 2022 by captain_dalan

[Callsign JoNay]

2 hours ago, captain_dalan said:

Tacview-20220618-201511-DCS-F-14 A high level clean EVAL.zip.acmi 156.75 kB · 1 download Tacview-20220618-202352-DCS-F-14 B high level clean EVAL.zip.acmi 169.53 kB · 1 download Tacview-20220618-203355-DCS-F-14 A high level clean EVAL no pylons on A.zip.acmi 153.13 kB · 1 download

One question still stands though....... are the palettes always added to the plane, or are they added to the missiles? 

Neither. The weight isn't added at all, with or without missiles, according to the testing methods Victory advised me to use. And I haven't seen it acknowledged by anyone from HB.

[Uxi]

On 6/17/2022 at 10:49 AM, WelshZeCorgi said:

I agree, would be interesting and unique, but we both know this would never happen. A lot of people would disagree with us. Most people would pick up pitchfork if they lost a dogfight and blamed the 0.2% difference in performance between 2 similar airframes, or crashed because they had a engine issue and either ignored it or didn't know what to do. 

 

Dynamic campaign system should definitely include some sort of maintenance pool to factor in attrition. Weapons inventory and limits on Phoenix, etc would naturally be a part of that.

[G.J.S]

There’s something that is bugging me about this report . . . .

Being that it is secondhand (at best) from an after action report over 40 years ago is the first thing.

Theres just little bits here and there . . . For instance.

Im in no way doubting the F-14 in its early iteration was a fast bird, but why go hot on two inbound -25’s at M2.4, only to close to visual and formate? The fuel wasted just to ‘join up’ is eye-watering.
I know about escort away from area of operation, but jeez, why make yourself look eminently hostile by blowing towards foreign fighters at Mach mucho? Muzic’s flight wasn’t the only airborne CAP, plus there were F-4’s a bit closer that could have intercepted and at the very least “tied up” the -25’s whilst the F-14’s placed themselves. 
 

Also, and this was something very prevalent during the Cold War, could the 2.4 be a little bit of disinformation? Make the ‘opposition’ expend time and money trying to develop something that can deal with a 2.4 cat, which at the time would be prohibitively expensive for any country, and hopefully break that country financially? The F-14 can certainly get close, but the difference between 2.3 & 2.4 can be millions of dollars and many months of trial and error for an opponent - maybe too much.
It’s the same with drunks at a bar - they always try to appear more pumped and skilled than they really are - intimidation. If the other guy is bigger, harder, faster than you, you are less likely to want to tango.

This incident certainly did happen, as did many more like it, but there’s just a few things . . . . 

 

[captain_dalan]

3 hours ago, Callsign JoNay said:

Neither. The weight isn't added at all, with or without missiles, according to the testing methods Victory advised me to use. And I haven't seen it acknowledged by anyone from HB.

Just checked and indeed, adding the missiles only adds the missile weight to the total aircraft weight. But what if the palettes are considered on at all times? If an empty F-14A is 40100lbs and the one we have without fuel and internal ammo is 42086, that's about 2000lbs extra, right? Did those pallets weigh about 500lbs each? If so, it would account for the extra weight.