PSA: F-14 Performance/FM Development Status + Guided Discussion

[draconus]

12 hours ago, maxsin72 said:

First, the true purpose of the glove vanes might surprise some people: they were intended to REDUCE STABILITY at high speed...

You didn't surprise anyone. Everybody was telling you already how useless they were in practice and this snippet only confirms it - so again - what's your point?

[IronMike]

@maxsin72 - look, I know you always come from a place of passion, and I really like that about you. You want the best for the Tomcat and the most out of that, and no one can really fault you for that. In fact: we are on your side, 100%. But, you also have to listen to the input we give you, because we're not trying to just shut you down, but to also give you the desired info that aligns your impressions better with the facts at hand. Remember the old performance thread? I already explained to you, about mach tuck and glove vanes and their purpose, here it is again:

"But let us take a step back and get really simple: how an aircraft performs is mostly defined by how much lift it can generate and how much drag it has. AOA is a primary driver for both lift and drag. The more lift, the more "upward" force available (and therefore G available), the more drag it gets decreases ability to maintain speed or ability to accelerate. The ability to increase AOA (and therefore lift/G) comes from the elevators in the rear of the F-14, which will "pick up" the nose and increase AOA. However, the elevators are pretty large and at large deflections they add drag.

When going supersonic (like Mach 1.4+) the acting lift point moves aft which causes the nose to want to point down (aka Mach Tuck). You can counter this by increasing stab deflection in the back to "pick up" the nose, but doing so adds drag and decreases lift. Another way to solve this is to add lift near the front of the aircraft, which simultaneously picks up the nose (increases AOA) and adds lift at the same time. Another side effect is that you don't need as much elevator deflection in the back, which decreases the drag caused from elevator deflection. Because there is less elevator needed to keep the nose up due to the glove vanes "helping out", theoretically there is more elevator travel available to further increase "G available" at these higher speeds.

However, at the end of the day it became apparent that the benefits of the glove vanes were outweighed by their maintenance burden so they were welded shut and deleted from later F-14 production runs."



I would suggest that we now move on from this topic in general, because else we will start to turn in circles. Thanks!

[Victory205]

This obsesión with glove vanes is a bit strange. They were there for the reasons that Iron Mike described above. However they were both simple and crude in execution. They added surface area forward, but at the same time, disrupted airflow over the inboard wing gloves. They made pitch slightly more sensitive, and caused mild buffet on extension and an increase in buffet during subsonic maneuvering, which is why we left the wing system in auto.

 

We didn’t pay much attention or give much thought to the things, other than occasionally extending them in the break. 

A lot of trivial aspects of the aircraft are far more important to enthusiasts that they were to crews and maintainers. I blame the British.

 

[maxsin72]

9 hours ago, draconus said:

You didn't surprise anyone. Everybody was telling you already how useless they were in practice and this snippet only confirms it - so again - what's your point?

Those words are not mine, who is speaking is Bio Baranek in the interview i have linked and he is speaking to common people so i can't understand your post.

My point was to understand the effect of glove vanes but, to have an exhaustive answer without controversy , after i asked the question in the forum, it was necessary to use google.

Edited October 1, 2021 by maxsin72

[maxsin72]

17 hours ago, Snappy said:

 

Actually several people gave you good answers within this forums.

However their answers seemed to somehow not align with your personal opinion on how things should be , so you didn’t acknowledge them or took extremely selective parts of their statements out of context.

No, i don't agree with you, you are only making another unuseful controversy because after i asked my question nobody gave me all the info i've found in Bio's interview, othewise show me who gave all those details.

[maxsin72]

6 hours ago, IronMike said:

@maxsin72 - look, I know you always come from a place of passion, and I really like that about you. You want the best for the Tomcat and the most out of that, and no one can really fault you for that. In fact: we are on your side, 100%. But, you also have to listen to the input we give you, because we're not trying to just shut you down, but to also give you the desired info that aligns your impressions better with the facts at hand. Remember the old performance thread? I already explained to you, about mach tuck and glove vanes and their purpose, here it is again:

"But let us take a step back and get really simple: how an aircraft performs is mostly defined by how much lift it can generate and how much drag it has. AOA is a primary driver for both lift and drag. The more lift, the more "upward" force available (and therefore G available), the more drag it gets decreases ability to maintain speed or ability to accelerate. The ability to increase AOA (and therefore lift/G) comes from the elevators in the rear of the F-14, which will "pick up" the nose and increase AOA. However, the elevators are pretty large and at large deflections they add drag.

When going supersonic (like Mach 1.4+) the acting lift point moves aft which causes the nose to want to point down (aka Mach Tuck). You can counter this by increasing stab deflection in the back to "pick up" the nose, but doing so adds drag and decreases lift. Another way to solve this is to add lift near the front of the aircraft, which simultaneously picks up the nose (increases AOA) and adds lift at the same time. Another side effect is that you don't need as much elevator deflection in the back, which decreases the drag caused from elevator deflection. Because there is less elevator needed to keep the nose up due to the glove vanes "helping out", theoretically there is more elevator travel available to further increase "G available" at these higher speeds.

However, at the end of the day it became apparent that the benefits of the glove vanes were outweighed by their maintenance burden so they were welded shut and deleted from later F-14 production runs."



I would suggest that we now move on from this topic in general, because else we will start to turn in circles. Thanks!

You are right, i have a lot of passion and i love F14. But i didn't ask to put glove vanes in the flight model, never and you know that if i think that's right to ask something i'll do it. My first question was how many deg/sec (instant turn rate) the experts on the forum think Snort was pulling in the video i have posted, the same video with the F14 with glove vanes. I was also hoping in a @Victory205 answer.

Edited October 1, 2021 by maxsin72

[IronMike]

On 10/1/2021 at 9:29 PM, maxsin72 said:

You are right, i have a lot of passion and i love F14. But i didn't ask to put glove vanes in the flight model, never and you know that if i think that's right to ask something i'll do it. My first question was how many deg/sec (instant turn rate) the experts on the forum think Snort was pulling in the video i have posted, the same video with the F14 with glove vanes. I was also hoping in a @Victory205 answer.

 

Well, the problem is, it is impossible to decipher that from a video. We even discussed it with @fat creason, and I also don't think @Victory205 will be able to answer that question beyond a guesstimate. There is simply no way a video, and such a low quality, old video can serve as anything accurate, especially not to estimate some turn rate. We do know however that the turn rate that is depicted in the video, is well within the limits of the charts and pilot accounts, because that is just what the jet was possible to do. It is likely that it is at the upper limit, that the maximum possible is being squeezed out of it, etc... But you can already hear in the language that I am using "squeezed", "maximum possible" and so on and so forth: it is far, far away from a scientific approach, from anything that holds up to aeronautics. Remember the discussion we had about Snort in the first place - God rest his soul - his tales were also under special conditions, detrimental to aircraft maintenance, etc. All of which btw is possible in the sim, all of which you can overstress to your heart's desire. So, in the end, the best that we get out of a video like that, is admiration for an awesome turn, done by a great pilot in the greatest jet that ever graced the skies... Everything else, needs to be continued to be carefully extracted as we did so far: from windtunnel tests, from charts and from the tremendous benefit we get from the tremendous effort that our SME puts into the aircraft module. He gets hands on, tunes hands on, tweaks hands on, and nothing can and will ever get closer than that, especially not a video, even if you share it with the very best intent, which is why I am sorry that I have to disappoint you here. Cherish it for what it is, Maxsin: pure beauty and raw power caught on camera, for us who came afterwards to admire and applaud.

I wish you all a great weekend guys! Have fun flying, and remember: check six, or the boogeyman will get you!

 

Edited October 7, 2021 by IronMike

[Victory205]

Last thing I want to waste time on is parsing trite statements from my peers, some of whom I’ve known for three and a half decades as if they have suddenly appeared in a burning bush, or study a YouTube video frame by frame like it’s the freaking Zapruder Film. 
 

It’s Friday, go out and enjoy life. 

[maxsin72]

2 hours ago, IronMike said:

 

Well, the problem is, it is impossible to decipher that from a video. We even discussed it with @fat creason, and I also don't think @Victory205 will be able to answer that question beyond a guesstimate. There is simply no way a video, and such a low quality, old video can serve as anything accurate, especially not to estimate some turn rate. We do know however that the turn rate that is depicted in the video, is well within the limits of the charts and pilot accounts, because that is just what the jet was possible to do. It is likely that it is at the upper limit, that the maximum possible is being squeezed out of it, etc... But you can already hear in the language that I am using "squeezed", "maximum possible" and so on and so forth: it is far, far away from a scientific approach, from anything that holds up to aeronautics. Remember the discussion we had about Snort in the first place - God rest his soul - his tales were also under special conditions, detrimental to aircraft maintenance, etc. All of which btw is possible in the sim, all of which you can overstress to your heart's desire. So, in the end, the best that we get out of a video like that, is admiration for an awesome turn, done by a great pilot in the greatest jet that ever graced the skies... Everything else, needs to be continued to be carefully extracted as we did so far: from windtunnel tests, from charts and from the tremendous benefit we get from the tremendous effort that our SMEs put into the aircraft module. They get hands on, tune hands on, tweak hands on, and nothing can and will ever get closer than that, especially not a video, even if you share it with the very best intent, which is why I am sorry that I have to disappoint you here. Cherish it for what it is, Maxsin: pure beauty and raw power caught on camera, for us who came afterwards to admire and applaud.

I wish you all a great weekend guys! Have fun flying, and remember: check six, or the boogeyman will get you!

 

 

1 hour ago, Victory205 said:

Last thing I want to waste time on is parsing trite statements from my peers, some of whom I’ve known for three and a half decades as if they have suddenly appeared in a burning bush, or study a YouTube video frame by frame like it’s the freaking Zapruder Film. 
 

It’s Friday, go out and enjoy life. 

Ok guys, i understood, thank you for yours answers

Edited October 1, 2021 by maxsin72

[illegal1984]

Agreed. Just for reference though, it would appear that he is getting that turn rate by going from 0.8-0.9 m somewhere and cutting the throttle for a massive deceleration while in the turn. Do that and the jet will respond in much the same manner in the sim as you see in the vid, current FM or not. Wings don’t move because he is probably way past 6.5 Gs. Note, it tapers off in the end because he is basically out of energy. Cool looking at airshows…not the best move in a real fight. Hell of a pilot.

[draconus]

7 hours ago, illegal1984 said:

Wings don’t move because he is probably way past 6.5 Gs.

It's just wings manually set aft most likely.

[maxsin72]

9 hours ago, illegal1984 said:

Agreed. Just for reference though, it would appear that he is getting that turn rate by going from 0.8-0.9 m somewhere and cutting the throttle for a massive deceleration while in the turn. Do that and the jet will respond in much the same manner in the sim as you see in the vid, current FM or not. Wings don’t move because he is probably way past 6.5 Gs. Note, it tapers off in the end because he is basically out of energy. Cool looking at airshows…not the best move in a real fight. Hell of a pilot.

Very interesting, i'll try to do it for fun

[Slant]

12 hours ago, IronMike said:

So, in the end, the best that we get out of a video like that, is admiration for an awesome turn, done by a great pilot in the greatest jet that ever graced the skies...

 

 

I respectfully disagree, the best we can get out of the video is those damn vapes. We need em. If I can still see anything of the a/c behind the canopy, there need to be more vapes added.

[captain_dalan]

10 hours ago, maxsin72 said:

Very interesting, i'll try to do it for fun

I've done some pretty wild 'bat turns' myself with proper technique. In actual combat configuration too. I'll look up the tackview files if you like  

[LanceCriminal86]

Instead of the Glove Vanes, I'd like to lobby for Victory205 recording LSO lines to judge all of our traps without mercy. All liveries will be locked except for RAG liveries from VF-101 and VF-124, and they will only be the bland line ones. Once the VictoryAI™ has seen consistent on speed on AOA 3-wires enough to legit qual you, other skins will unlock.

 

Fly bad enough and the F-14 module locks out, and you are forced to use an alternate low-fidelity C-123 module with the only available mission being flying prank dog droppings to and from Kutaisi.

 

 

If we're going to talk about changes that might actually be impactful though, how about the comments on pulling fuses for the maneuvering flaps to put the jet in a cleaner cruise/loiter configuration? Is there any truth to that in actual fleet usage or would the impact to fuel economy be minimal and we should just stop sucking at refueling?

[maxsin72]

2 hours ago, captain_dalan said:

I've done some pretty wild 'bat turns' myself with proper technique. In actual combat configuration too. I'll look up the tackview files if you like  

Thx it would be interesting to see the tackview file

[eatthis]

10 hours ago, captain_dalan said:

I've done some pretty wild 'bat turns' myself with proper technique. In actual combat configuration too. I'll look up the tackview files if you like  

bat turn?

 

[draconus]

2 hours ago, eatthis said:

bat turn?

Turn on a dime

[Top Jockey]

13 hours ago, LanceCriminal86 said:

Instead of the Glove Vanes, I'd like to lobby for Victory205 recording LSO lines to judge all of our traps without mercy. All liveries will be locked except for RAG liveries from VF-101 and VF-124, and they will only be the bland line ones. Once the VictoryAI™ has seen consistent on speed on AOA 3-wires enough to legit qual you, other skins will unlock.

 

Fly bad enough and the F-14 module locks out, and you are forced to use an alternate low-fidelity C-123 module with the only available mission being flying prank dog droppings to and from Kutaisi.

 

 

If we're going to talk about changes that might actually be impactful though, how about the comments on pulling fuses for the maneuvering flaps to put the jet in a cleaner cruise/loiter configuration? Is there any truth to that in actual fleet usage or would the impact to fuel economy be minimal and we should just stop sucking at refueling?

 

Highly interesting and original suggestion - I'll give you that. 

(If you search for it, @Victory205 once suggested to activate the ship's CIWS on everyone who failed to be at the correct on speed.)

 

But it's already bad enough to only arrive at DCS 2.7 at previous week for the first time (as before I was on DCS 2.5 with Win 7).

... and therefore I'm now failing to properly grab the arresting cables 70 % of the times... and Jester ejecting alone in panic 10 % of those times, even if a mighty F-14 pilot like me still manage to save the aircraft.

 

But jokes aside, if one wants realism, I guess that's one of those cases where the 'discipline' factor comes in - acquire and maintain proper carrier landing procedures.

As curiosity, I believe in the F/A-18C module the tailhook rebound happened right from the early days if one failed to arrive in the correct parameters.

Edited October 3, 2021 by Top Jockey

[captain_dalan]

15 hours ago, maxsin72 said:

Thx it would be interesting to see the tackview file

Tacview-20211003-152531-DCS-F-14 low level EVAL.zip.acmi

 

I had the old track files deleted (probably  as a result of routine track maintenance), but no matter, i just recorded these and they are close enough. The first two are a couple of 5g warmup turns, i tried to stay between 4.9 and 5.1g in a consistent sustained turn to get the feel for the aircraft. For me it's a must in the F-14. I can't just jump in and scratch at the air for every pound of lift i can get right after takeoff. 

The configuration is 54000pds gross weight, 4 Sparrows, 4 Winders, full 20mm box and whatever is left for the fuel, probably around 55-60%. I had the fuel burn disabled in the settings, so the data would be consistent throughout the entire flight. Try this with an airshow load and you go Pazuzu with this plane. Wings were left in auto as where the flaps. So to minimize structural damage. Airspeed never exceeded 450 knots and i tried to enter into most breaks with less then or at 400. Even so, i seemed to have spiked at 10g somehow! That's on my though.

Observations:
1. You do the full aft stick and ride the 32-33 degree (true degrees, not units) AoA and you can do north of 30 degrees per second for VERY short periods of time. I think i spiked at 35 degrees per second or so. Be ready to dance and i mean DANCE on your rudder pedals. If you don't have pedals, assign rudder inputs to some analogue alternative. You can't stay on the "edge of the knife" without them. This kind of turn, if entered properly will give you about 270 degrees before you bleed out and are near stall. More or less, depending on your entry speed. Even so, the efficiency of your turn (that is, the rate) is highly variable. It starts slower, then picks up rapidly, then drops rapidly and then you just sort of hang there. 

2. You do a 25 degree AoA and you max out about 20-24 degrees per second, BUT you get to sustain it longer, and you end up with a higher average turn rate then you do when you pull to the limit. This way with a proper entry you go for over 450 degrees before you bleed out below 150 knots. IMO, but better strategy for most dogfights. Keep the 33AoA for last second jinks and guns-d, while cornering at 25 AoA. 

3. It's actually possible (and if you look carefully you'll see it) to actually go over 32-33 degrees AoA when you enter the break at higher airspeeds. I think i managed 35 degrees or so, even with the wings forward. This is transient AoA. It can't be sustained. For a very short time the momentum and lifting body take hold and guide your nose further up then otherwise possible. With wings back and with more airspeed it's even possible to pull more then 35. I've seen data that state more then 40.

Do note that while these sort of shenanigans can give Hornets a run for their money, they are not always or even often the best of ideas. They leave you like a dry twig in the wind, just floating there with no energy to speak of. You may get your snapshot or get the bandit to panic and do something stupid. But after that, especially in the A, it takes some time to get the knots (and the capability to do something with them) back. Just take a look how long my extensions are. And i don't mean hair or nail extensions

Hope you liked the track and have a great weekend! 

[maxsin72]

2 hours ago, captain_dalan said:

Tacview-20211003-152531-DCS-F-14 low level EVAL.zip.acmi 163.57 kB · 4 downloads

 

I had the old track files deleted (probably  as a result of routine track maintenance), but no matter, i just recorded these and they are close enough. The first two are a couple of 5g warmup turns, i tried to stay between 4.9 and 5.1g in a consistent sustained turn to get the feel for the aircraft. For me it's a must in the F-14. I can't just jump in and scratch at the air for every pound of lift i can get right after takeoff. 

The configuration is 54000pds gross weight, 4 Sparrows, 4 Winders, full 20mm box and whatever is left for the fuel, probably around 55-60%. I had the fuel burn disabled in the settings, so the data would be consistent throughout the entire flight. Try this with an airshow load and you go Pazuzu with this plane. Wings were left in auto as where the flaps. So to minimize structural damage. Airspeed never exceeded 450 knots and i tried to enter into most breaks with less then or at 400. Even so, i seemed to have spiked at 10g somehow! That's on my though.

Observations:
1. You do the full aft stick and ride the 32-33 degree (true degrees, not units) AoA and you can do north of 30 degrees per second for VERY short periods of time. I think i spiked at 35 degrees per second or so. Be ready to dance and i mean DANCE on your rudder pedals. If you don't have pedals, assign rudder inputs to some analogue alternative. You can't stay on the "edge of the knife" without them. This kind of turn, if entered properly will give you about 270 degrees before you bleed out and are near stall. More or less, depending on your entry speed. Even so, the efficiency of your turn (that is, the rate) is highly variable. It starts slower, then picks up rapidly, then drops rapidly and then you just sort of hang there. 

2. You do a 25 degree AoA and you max out about 20-24 degrees per second, BUT you get to sustain it longer, and you end up with a higher average turn rate then you do when you pull to the limit. This way with a proper entry you go for over 450 degrees before you bleed out below 150 knots. IMO, but better strategy for most dogfights. Keep the 33AoA for last second jinks and guns-d, while cornering at 25 AoA. 

3. It's actually possible (and if you look carefully you'll see it) to actually go over 32-33 degrees AoA when you enter the break at higher airspeeds. I think i managed 35 degrees or so, even with the wings forward. This is transient AoA. It can't be sustained. For a very short time the momentum and lifting body take hold and guide your nose further up then otherwise possible. With wings back and with more airspeed it's even possible to pull more then 35. I've seen data that state more then 40.

Do note that while these sort of shenanigans can give Hornets a run for their money, they are not always or even often the best of ideas. They leave you like a dry twig in the wind, just floating there with no energy to speak of. You may get your snapshot or get the bandit to panic and do something stupid. But after that, especially in the A, it takes some time to get the knots (and the capability to do something with them) back. Just take a look how long my extensions are. And i don't mean hair or nail extensions

Hope you liked the track and have a great weekend! 

Thanks really a lot, both for the interesting info (i've seen your tacview file) and for your time you gift me/us to share all the details

I'm trying to understand if there is a way tou use wings swept back to bleed speed and turn very tight when chasing another plane who can use airbrakes over mach 0.7 (i've seen airbraks want not work for F14 over mach 0.7) and is able to decelarate very quickly when the pilot wants to be overtaked (f18 or M2000 for example).

I also wish you a beautiful WE.

 

Edited October 3, 2021 by maxsin72

[eatthis]

9 hours ago, draconus said:

Turn on a dime

oh bury the stick and dump all your energy?

[IronMike]

On 10/2/2021 at 11:08 PM, LanceCriminal86 said:

If we're going to talk about changes that might actually be impactful though, how about the comments on pulling fuses for the maneuvering flaps to put the jet in a cleaner cruise/loiter configuration? Is there any truth to that in actual fleet usage or would the impact to fuel economy be minimal and we should just stop sucking at refueling?

 

According to the SME feedback I got, in orbits or slow cruise MF deployment, you'd hold them in with your thumb on the DLC wheel until your thumb got sore and stiff like a burning piece of wood. Pulling fuzes? Sounds more like sailors yarn to me, but I am not sure at all in this particular case. It was however in most other cases where pulling fuzes was mentioned (valid exceptions not included).

[Tulkas]

On 10/3/2021 at 12:08 AM, LanceCriminal86 said:

Instead of the Glove Vanes, I'd like to lobby for Victory205 recording LSO lines to judge all of our traps without mercy.

I’d pay 80 bucks for that if includes extended debriefings, «DCS Victory205 LSO». 100 if includes voice over for the pilot on a serie of RIO tutorials missions, calling names whe lock is lost or setting the radar wrong

[Hummingbird]

Did some testing today to see if the maneuver flaps/slat schedule was on point, but alas:

 

 

That's M 0.52, 18 units AoA, but zero extension of maneuver flaps/slats. According to the manual, at SL the maneuver slat/flaps should start to extend at M 0.58, be about half way extended by 0.55, and by 0.52 they should be fully extended: 

Spoiler

 

 

Based on further testing it appears the extension schedule is incorrectly set to initiate right below M 0.52, instead of at the correct M 0.58.

 

Now forgive me if I'm mistaken, but wasn't this listed as addressed?

Edited October 5, 2021 by Hummingbird