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

[eatthis]

a thought just occured to em. i guess the cadc dealt witht he vanes?
if so was the cadc processing done by the same cpu as the avionics/hud etc?
if yes could/did they delete the programming for the vanes and reuse the spare capacity for some other goodies? i know they did do that kind of thing but dont know specifics

 

[Airhunter]

5 hours ago, maxsin72 said:

I think your assumption is wrong: also small surfaces at high speed generate strong lift and gloves vanes function was just that.

 

Lift AND drag. Said vanes also sit way ahead of the CG and center of lift, which pretty much should deminish pitch rates as they are non-moving surfaces. To my understnding the glove vanes were intended for mostly supersonic maneuvering and more stability in that regime. Why they would be out during a 300-400KIAS regime, I honestly don't know. My only guess would be to negate some trim drag with the wings at 68.

Edited September 28, 2021 by Airhunter

[captain_dalan]

13 hours ago, Katj said:

I think the largest effect is that they move the center of lift forwards, which lowers trim drag and of course increases responsiveness in pitch.

Of course they say that the effect was so small they didn't need them and inactivated them in the 90s. Nevertheless the super tomcat 21 proposal featured enlarged gloves that kind of resembles the original gloves with the vanes extended. Don't ask me how that affected stability with wings full forward.

Yeah, but that would be at mach 1.something (3 or 4 if memory serves?) when due to the changes in airflow, the portion of the wings that generates lift will be moved further back. 

11 hours ago, maxsin72 said:

I think your assumption is wrong: also small surfaces at high speed generate strong lift and gloves vanes function was just that.

Google the equations for lift generation if you think i'm wrong. 
As for the high speed, look at the above answers. Yeah at supersonic speeds their effect may be measurable, but at airshow speeds that the OP mentions? In my opinion hardly any. Certainly not any that would improve your capability to generate noticeably more lift. 

[IronMike]

16 hours ago, maxsin72 said:

I think your assumption is wrong: also small surfaces at high speed generate strong lift and gloves vanes function was just that.

 

Nope, their function was to help with mach tuck and allow you to turn better at speeds no one would turn anyway. Did they add a little bit? Sure. But obviously not enough, so that the Navy would have deemed them useful, which is why ultimately they got welded shut/ removed.  

[maxsin72]

On 9/28/2021 at 1:37 AM, captain_dalan said:

The contribution to the lift would be roughly proportional to the increase in lifting surface, which doesn't look like all that much to be honest. 

 

5 hours ago, captain_dalan said:

Yeah, but that would be at mach 1.something (3 or 4 if memory serves?) when due to the changes in airflow, the portion of the wings that generates lift will be moved further back. 

Google the equations for lift generation if you think i'm wrong. 
As for the high speed, look at the above answers. Yeah at supersonic speeds their effect may be measurable, but at airshow speeds that the OP mentions? In my opinion hardly any. Certainly not any that would improve your capability to generate noticeably more lift. 

I confirm i think your assumption is wrong: you talk about small surfaces in your first post and my answer was that also small surfaces generate strong lift at high speed, in your answer you didn't mention speed as a crucial factor.

So please tell me if this is wrong or right because with your answer you insinuate something i did't wrote.

21 minutes ago, IronMike said:

 

Nope, their function was to help with mach tuck and allow you to turn better at speeds no one would turn anyway. Did they add a little bit? Sure. But obviously not enough, so that the Navy would have deemed them useful, which is why ultimately they got welded shut/ removed.  

So you confirm that glove vains allow you to turn better at speeds. I thank you because i wrote the same thing.

[Hotel Tango]

Jesus christ.

[Katj]

 
Nope, their function was to help with mach tuck and allow you to turn better at speeds no one would turn anyway. Did they add a little bit? Sure. But obviously not enough, so that the Navy would have deemed them useful, which is why ultimately they got welded shut/ removed.  

Maybe the navy just didn't use them enough for them to be worth the expense. I.e. the navy didn't maneuver at supersonic speeds like they originally thought they might. Especially after the fall of the Soviet Union.

[maxsin72]

52 minutes ago, Katj said:

 

Maybe the navy just didn't use them enough for them to be worth the expense. I.e. the navy didn't maneuver at supersonic speeds like they originally thought they might. Especially after the fall of the Soviet Union.

I've also read F14D has max speed limited to mach 1.88 due to ramp-system=inlet fixed, so to require less expensive maintenance. I think the same is for glove vains.

[IronMike]

12 hours ago, maxsin72 said:

 

I confirm i think your assumption is wrong: you talk about small surfaces in your first post and my answer was that also small surfaces generate strong lift at high speed, in your answer you didn't mention speed as a crucial factor.

So please tell me if this is wrong or right because with your answer you insinuate something i did't wrote.

So you confirm that glove vains allow you to turn better at speeds. I thank you because i wrote the same thing.

 

You are misquoting by cutting off my sentence half way: "...to turn better at speeds no one would turn anyway." AKA at such high speeds, where dogfights do not really happen.

Edited September 29, 2021 by IronMike

[Airhunter]

7 hours ago, maxsin72 said:

I've also read F14D has max speed limited to mach 1.88 due to ramp-system=inlet fixed, so to require less expensive maintenance. I think the same is for glove vains.

 

Only with certain store configs. 

 

 

 

EDIT: Point being. You can NOT just make up anecdotal performance or have test data and charts open for arbitrary interpretation. NATOPS procedures and limits are often written in blood and there for a good reason. And SME feedback or comments can also often be wrong based on the timeframe and fleeting memory. A YT video is all but scientific, factual evidence and a very rough estimate at the very best. Numbers make airplanes, not imagination.

Edited September 29, 2021 by Airhunter

[maxsin72]

2 hours ago, IronMike said:

 

You are misquoting by cutting off my sentence half way: "...to turn better at speeds no one would turn anyway." AKA at such high speeds, where dogfights do not really happen.

 

I have quoted the part of your sentence that is pertinent with what i wrote. When you write "at speeds no one would turn anyway", you miss my point. If you didn't understand, my point is that also small surfaces at high speeds generate strong lift, period, end of my sentence, this is a general phisic law

[Airhunter]

9 minutes ago, maxsin72 said:

I have quoted the part of your sentence that is pertinent with what i wrote. When you write "at speeds no one would turn anyway", you miss my point. If you didn't understand, my point is that also small surfaces at high speeds generate strong lift, period, end of my sentence, this is a general phisic law

 

Ok, and? 

[maxsin72]

2 hours ago, Airhunter said:

 

Only with certain store configs. 

 

 

 

EDIT: Point being. You can NOT just make up anecdotal performance or have test data and charts open for arbitrary interpretation. NATOPS procedures and limits are often written in blood and there for a good reason. And SME feedback or comments can also often be wrong based on the timeframe and fleeting memory. A YT video is all but scientific, factual evidence and a very rough estimate at the very best. Numbers make airplanes, not imagination.

 

I have never pretended to give "numbers', i have only asked a question about, approximately, how many deg the F14 was turning in the video. And i also have asked what SME could think about that, so please keep calm

Anyway the FM of HB F14 is also based on SME knowledge and not only on NATOPS charts and i think HB made the right choice

[maxsin72]

1 minute ago, Airhunter said:

 

Ok, and? 

... And It's not correct to affirm The contribution to the lift would be roughly proportional to the increase in lifting surface, which doesn't look like all that much to be honest. 

because the contribution to the lift increase also with (air) speed and, with wings at 68 deg and automatic wings swept, air speed usually is high.

[Airhunter]

Just now, maxsin72 said:

... And It's not correct to affirm The contribution to the lift would be roughly proportional to the increase in lifting surface, which doesn't look like all that much to be honest. 

because the contribution to the lift increase also with (air) speed and, with wings at 68 deg and automatic wings swept, air speed usually is high.

 

You seemingly ignored what I wrote beforehand. But anyway, let's get back on topic, shall we? 

[maxsin72]

49 minutes ago, Airhunter said:

 

You seemingly ignored what I wrote beforehand. But anyway, let's get back on topic, shall we? 

And you seemingly ignored what i wrote beforehand. Glad to see that finally you want get back on topic. 

Edited September 29, 2021 by maxsin72

[captain_dalan]

Generated lift is equal to the lift coefficient (Cl) times the density of the air (r) times half of the square of the velocity (V) times the WING AREA (A).
Now some come here with willingness to learn, others not so much. Chose whatever path you want, but cutting and quoting posts out of context is certainly a valid way to go, if that is the choice you've made. Also, did you fail to notice that "at airshow speeds that the OP mentions" disclaimer i put in that post? Or was it convenient to omit it? It's in your quote after all. 
 

[lunaticfringe]

Re: glove vanes: 

See the automatic deployment schedule of operation in the subsonic regime between M 0.2 and M 0.8 found in AAA-1.  

Note the CL Max line in AAA-1.1. 
Note the CL Max line in AAP-1.1 are the same as AAA-1.1 for the various configurations.

And recognize the performance tables for AAP-1.1 are used also for the F-14D.

Glove vanes: < 20 square feet of additional wing added so much lift to the equation against the already near 1100 square feet of lift between the wings, glove, and fuselage tunnel that they don't register a difference once deleted.

They look cool.  They reduce stability fractionally at high mach.  And they are a statistical nonfactor everywhere in the equation for what can be quantified by the data at hand.  
 

Edited September 30, 2021 by lunaticfringe

[IronMike]

7 hours ago, lunaticfringe said:

Re: glove vanes: 

See the automatic deployment schedule of operation in the subsonic regime between M 0.2 and M 0.8 found in AAA-1.  

Note the CL Max line in AAA-1.1. 
Note the CL Max line in AAP-1.1 are the same as AAA-1.1 for the various configurations.

And recognize the performance tables for AAP-1.1 are used also for the F-14D.

Glove vanes: < 20 square feet of additional wing added so much lift to the equation against the already near 1100 square feet of lift between the wings, glove, and fuselage tunnel that they don't register a difference once deleted.

They look cool.  They reduce stability fractionally at high mach.  And they are a statistical nonfactor everywhere in the equation for what can be quantified by the data at hand.  
 

 

 

Which is exactly why this entire discussion is hypothetical. We always said that we might do the glove vanes, but if we do them, only for visual purposes and with zero impact on the flight model. This will not change, as much as we hate that it may disappoint some, but we stand by that.

Edited September 30, 2021 by IronMike

[Victory205]

3 hours ago, IronMike said:

 

Which is exactly why this entire discussion is hypothetical. We always said that we might do the glove vanes, but if we do them, only for visual purposes and with zero impact on the flight model. This will not change, as much as we hate that it may disappoint some, but we stand by that.

If the Navy hadn’t chosen to disable the Glove Vanes, then the Tomcat would still be flying today, the Covid pandemic would have never happened, there would be World Peace, and Pierre Sprey wouldn’t have ended up as a record producer.
 

So sad.

 

BTW, the method for getting the glove vanes to extend is to either use Bomb Mode, or sweep the wings aft of 55 and then select Bomb. Pilots did it for aesthetics. It also created more vapes if conditions were favorable.
 

And World Peace.

Edited September 30, 2021 by Victory205

[captain_dalan]

10 hours ago, lunaticfringe said:

Re: glove vanes: 

See the automatic deployment schedule of operation in the subsonic regime between M 0.2 and M 0.8 found in AAA-1.  

Note the CL Max line in AAA-1.1. 
Note the CL Max line in AAP-1.1 are the same as AAA-1.1 for the various configurations.

And recognize the performance tables for AAP-1.1 are used also for the F-14D.

Glove vanes: < 20 square feet of additional wing added so much lift to the equation against the already near 1100 square feet of lift between the wings, glove, and fuselage tunnel that they don't register a difference once deleted.

They look cool.  They reduce stability fractionally at high mach.  And they are a statistical nonfactor everywhere in the equation for what can be quantified by the data at hand.  
 

 

Amen to that

[maxsin72]

I acknowledge that no one within this space has been able to give me an exhaustive answer about glove vanes. Instead, I feel a great desire to make an unuseful controversy.

Fortunately, google exists, next time will be my first choice to ask questions.

 

2. Were the “glove vanes” effective?

First, the true purpose of the glove vanes might surprise some people: they were intended to REDUCE STABILITY at high speed, to paraphrase the NATOPS manual. Yes, reduce it, because at high speed with the wings swept the F-14 was too stable in pitch, which meant it couldn’t turn. The speeds I’m talking about are above Mach 1.35, which is where the computer-programmed deployment of glove vanes started. The glove vanes allowed the F-14 to meet performance requirements for supersonic maneuverability. The pilot could also deploy glove vanes at lower speeds. Were they effective? I think so, in their intended purpose. But did they have a _significant_ impact on F-14 performance? That’s debatable, because we rarely flew above Mach 1.35, and below that speed they just didn’t have much effect on aircraft performance. But the glove vanes also came out in “Bomb” mode on the wingsweep, so they helped stabilize the aircraft during high angle bomb runs. Also, they were deactivated and then deleted, so the Navy and Grumman considered them “expendable.”

 Dave “Bio” Baranek

https://theaviationgeekclub.com/qa-with-a-former-f-14-tomcat-rio-dave-bio-baranek-answers-your-questions/

 

[lunaticfringe]

4 hours ago, maxsin72 said:

I acknowledge that no one within this space has been able to give me an exhaustive answer about glove vanes. Instead, I feel a great desire to make an unuseful controversy.

Fortunately, google exists, next time will be my first choice to ask questions.

You have a former F-14 pilot in this thread telling you that they didn't do anything but fail to bring about world peace (and keep Sprey out of the mixing booth- but let's not go crazy now) in their absence, rather than a RIO.  Bio's a great guy; I've talked to him.  HB has talked to him.  HB also has other SME staff- for both seats.  

 

I don't know about you, but I tend to trust/defer to the guys in the front seat on the front seat stuff, and the guys in the back seat (like Bio) on the back seat stuff.  YMMV.  

Edited October 1, 2021 by lunaticfringe

[RustBelt]

13 hours ago, IronMike said:

 

Which is exactly why this entire discussion is hypothetical. We always said that we might do the glove vanes, but if we do them, only for visual purposes and with zero impact on the flight model. This will not change, as much as we hate that it may disappoint some, but we stand by that.

 

 

Just take it away. Say "you kids got on our nerves so nobody gets glove vanes!" And be done with it. 

[Snappy]

4 hours ago, maxsin72 said:

I acknowledge that no one within this space has been able to give me an exhaustive answer about glove vanes. Instead, I feel a great desire to make an unuseful controversy.

Fortunately, google exists, next time will be my first choice to ask questions.

 

2. Were the “glove vanes” effective?

First, the true purpose of the glove vanes might surprise some people: they were intended to REDUCE STABILITY at high speed, to paraphrase the NATOPS manual. Yes, reduce it, because at high speed with the wings swept the F-14 was too stable in pitch, which meant it couldn’t turn. The speeds I’m talking about are above Mach 1.35, which is where the computer-programmed deployment of glove vanes started. The glove vanes allowed the F-14 to meet performance requirements for supersonic maneuverability. The pilot could also deploy glove vanes at lower speeds. Were they effective? I think so, in their intended purpose. But did they have a _significant_ impact on F-14 performance? That’s debatable, because we rarely flew above Mach 1.35, and below that speed they just didn’t have much effect on aircraft performance. But the glove vanes also came out in “Bomb” mode on the wingsweep, so they helped stabilize the aircraft during high angle bomb runs. Also, they were deactivated and then deleted, so the Navy and Grumman considered them “expendable.”

 Dave “Bio” Baranek

https://theaviationgeekclub.com/qa-with-a-former-f-14-tomcat-rio-dave-bio-baranek-answers-your-questions/

 

 

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.