F-14B acceleration correct?

[maxsin72]

17 minutes ago, IronMike said:

 

Hey Maxsin, yes we of course know who Mike Ciminera was, and we all know the video. But - sorry that there is always a but - this is not unsimilar to the talk we once had about Snorti. Now Ciminera and Snorti are nothing of the like, even if he may have been buddies with his dad, most likely, hehe - but the point is: the mach 2.4 is something that was a) wanted and b) achieved once only (maybe twice, not that I know of), under very special conditions.

Having someone in the backseat manually temper with the ramps to make it go past what the schedule would allow, is not really worth modeling. What for? So you can once fly all the way to M2.41 and then have to immediately eject, because you ran out of fuel? And mind you - only if we modeled the ability for the RIO to pull some buses or the likes, and then also only if you actually found a RIO who would do it properly.

At M 2.34 even, you will be just empty, unless you cheat and dive ofc. Rarely will it matter to you, to be beyond M1.6.

These are - like Snorts example with the flaps - all edge cases, exceptions, not under normal circumstances and also irrelevant to accurate modeling. How much G it can pull is very different, because that can happy anywhere, any time. Going M 2.41, I can assure you, is an exercise you would do once. And again, only if we gave you the tools, through a lot of investment from our side for little return.

What is important, is that it meets the performance under normal, realistic circumstances, and not edge cases or special circumstances. This is why it will take you to 2.34 ish. Since everything else is modeled correctly, I bet you, if we disabled the ramp stuff or have it set correctly, we could prolly reach 2.4 (when done with the performance tweaks). But again, you couldnt even do it on your own. And we certainly wouldn't model that for Jester. It does not serve you anything. It is not like you can fly around at M 2.4 for more than couple seconds after you reached it anyway. And it would likely take you 10-20 min to get there in the first place.

These numbers give ballparks, and again are here mentioned to an audience who doesnt see a difference between M2.34 and M 2.41. That is not of any interest to them. Furthermore, tests are sometimes done to prove a point. After the point was proven, the M was limited to 1.8x (Victory mentioned the exact number in this thread iirc, you can check). There is a reason for it.

We need to make sure it reaches 2.34 ish under normal circumstances. Not 2.41 in some rigged situation. And what we do make sure, is that the performance is such so that if we did rig the situation, you could reach 2.41 theoretically. Because that is what most of these tests are: theoretic. And so, theoretically, you could reach 2.41 with ours as well. But there is no need to provide such circumstances, even if you would like to have it. Even if you really, really wished for it, trust me, you would get little to nothing out of it.

 

Thx for your kind answer. The problem is that it's not possible to go past mach 2.2 also diving with full afterburner with almost no fuel. So if only was possible to see mach 2.34 it would be great.

Edited June 17, 2021 by maxsin72

[dundun92]

2 minutes ago, Mistang said:

Wikipedia implies they also limited g.

wikipedia is not a reliable source over actual flight manuals and first hand SME accounts.

[GGTharos]

4 minutes ago, Mistang said:

Yes I mean hidden limiters like glove vanes.

 

You clearly do not understand the subject.  The glove vane is not a g-limiter.   It adds lift, which allows the aircraft to pull a certain amount g (more than without it) at a certain speed.  7.5g at M1.4 is quite respectable.  A high mach pulling g is more difficult for a number of reasons that we won't go into.

 

G-Limiters are devices that actively prevent you from exceeding a given g limit.  The glove vanes are an aerodynamic feature and absolutely do no such thing, there's nothing like a 'hidden g-limiter', and there are no hidden g-limits either.

[Mistang]

1 minute ago, GGTharos said:

 

You clearly do not understand the subject.  The glove vane is not a g-limiter.   It adds lift, which allows the aircraft to pull a certain amount g (more than without it) at a certain speed.  7.5g at M1.4 is quite respectable.  A high mach pulling g is more difficult for a number of reasons that we won't go into.

 

G-Limiters are devices that actively prevent you from exceeding a given g limit.  The glove vanes are an aerodynamic feature and absolutely do no such thing, there's nothing like a 'hidden g-limiter', and there are no hidden g-limits either.

The g curve is basically flat regardless of speed. 

[GGTharos]

3 minutes ago, Mistang said:

Wikipedia implies they also limited g.

 

No, it doesn't.  The do the opposite, they add lift and g capability.

 

3 minutes ago, Mistang said:

but we're attacking sources at this point.

 

No, just your understanding of words and the far-fetched imagination of trying to make them mean something they do not.

 

3 minutes ago, Mistang said:

my only question is did the tomcat ever hit 8g in real life? Was okie flying an A model when he made that claim and did he think it would matter?

 

Given that the average g chart starts at 9 and the tomcat is represented there, the answer is 'yes'.

[IronMike]

10 minutes ago, Mistang said:

Yes I mean hidden limiters like glove vanes.

 

Look, Mistang. We really want to help you get a better understanding, but you have to also listen a bit and be willing to learn. Thinking that glove vanes are G limiters, makes your knowledge on the subject extremely obvious to everyone: you have none. And I do not say this to put you down. I say this to invite you to overthink your position. We're not defending our believes here, but trying to share the facts with you, that you get mixed up quite a bit, or hung up on things that didnt even exist. Wikipedia is also a shit source for everything, that is just on the sides. But naturally, quick to look up. It is ok for a first glance, but none of what you quoted has even remotely to do with anything like G limiters. To the contrary, the glove vanes were meant to give you more turnability at higher speeds, but actually proved fairly useless in application, so got removed or welded shut. You know, no one dogfights at M 1.5 at 35000 feet...

Anyway, if you accept that your current stance of knowledge on this subject is limited, which we all can see, then it will be much easier to tell you, or explain to you how it was, how we model it, and why it was like that. We will tell you all we know, we have no secrets. But you have to accept that we are somewhat of experts on this topic while you are not, else it will simply turn into a yes-no-yes-no kinda circlejerk, that will not let us have a meaningful discussion. Again, it is an invitation to start fresh and then we can all learn together.

I am off for tonight, too, please all stay kind to each other. And thank you for the good talks. GN
 

5 minutes ago, maxsin72 said:

Thx for your kind answer. The problem is that it's not possible to go past mach 2.2 also diving with full afterburner with almost no fuel. So if only was possible to see mach 2.34 it would be great.

 

 

I hear you buddy, once we are done with the performance tweaks we need to test again and then see.

Edited June 17, 2021 by IronMike

[GGTharos]

3 minutes ago, Mistang said:

The g curve is basically flat regardless of speed. 

 

It's also flat for the F-15A/C at 9g ... and yet those aircraft can handily exceed this limit to reach 12.5.   Most of them aren't trashed due to over-g.

 

But sticking to the glove vanes enabling the F-14 to reach 7.5g to begin with - obviously not a problem.  At subsonic speeds you'll reach more g since you can achieve a higher AoA.

Edited June 17, 2021 by GGTharos

[maxsin72]

2 minutes ago, IronMike said:

 

Look, Mistang. We really want to help you get a better understanding, but you have to also listen a bit and be willing to learn. Thinking that glove vanes are G limiters, makes your knowledge on the subject extremely obvious to everyone: you have none. And I do not say this to put you down. I say this to invite you to overthink the position. We're not defending our believes here, but trying to share the facts with you, that you get mixed up quite a bit, or hung up on things that didnt even exist. Wikipedia is also a shit source for everything, that is just on the sides. But naturally, quick to look up. It is ok for a first glance, but none of what you quoted has even remotely to do with anything like G limits. To the contrary, the glove vanes were meant to give you more turnability at higher speeds, but actually proved fairly useless in application, so got removed or welded shut. You know, no one dogfights at M 1.5 at 35000 feet...

Anyway, if you accep that your current stance of knowledge on this subject is limited, which we all can see, then it will be much easier to tell you, or explain to you how it was, how we model it, and why it was like that. We will tell you all we know, we have no secrets. But you have to accept that we are somewhat of experts on this topic while you are not, else it will simply turn into a yes-no-yes-no kinda circlejerk, that will not have us a meaningful discussion. Again, it is an invitation to start fresh and then we can all learn together.

I am off for tonight, too, please all stay kind to each other. And thank you for the good talks. GN
 

 

I hear you buddy, once we are done with the performance tweaks we need to test again and then see.

 

Thank you, i like really very much your answer

[Mistang]

Just now, GGTharos said:

 

It's also flat for the F-15A/C at 9g ... and yet those aircraft can handily exceed this limit to reach 12.5.   Most of them aren't trashed due to over-g.

 

That's different because the eagle simply has a limiter.

 

Anyway whatever I appreciate the effort but I still don't get why it would say the glove vanes allow 7.5g.

[maxsin72]

7 minutes ago, Mistang said:

That's different because the eagle simply has a limiter.

 

Anyway whatever I appreciate the effort but I still don't get why it would say the glove vanes allow 7.5g.

Grumman successfully tested F14 airframe at 13G, Okie pulled 12.5 G because nobody told him about the changement of strenght to apply to the stick. The only problem to over G the cat is that the airframe is stressed by high g turns and this limit the lifetime of the frame very much.

Edited June 17, 2021 by maxsin72

[Mistang]

Just now, maxsin72 said:

Grumman successfully tested F14 airframe at 13G, Okie pulled 12.5 G because nobody told him about the changement of strenght to aplly to the stick. The only problem to over G the cat is that the airframe is stressed by high g turns and this limit the lifetime of the frame very much.

So we're just going to ignore the glove vanes thing I guess.

 

the very forces which destroy the plane would weaken the g gauge so that isn't reliable.

[maxsin72]

Just now, Mistang said:

So we're just going to ignore the glove vanes thing I guess.

 

the very forces which destroy the plane would weaken the g gauge so that isn't reliable.

Sorry but, as many already told you, it seems you are really confused and you don't understand the matter

[Mistang]

Just now, maxsin72 said:

Sorry but, as many already told you, it seems you are really confused and you don't understand the matter

Ok sure, "you're wrong", good reply as any.

[Frosty2124]

Just now, Mistang said:

Ok sure, "you're wrong", good reply as any.

not only Your're wrong but....

 

You won't listen to reason

 

You're just ignorant

 

i tried being nice

[Mistang]

Just now, Frosty2124 said:

not only Your're wrong but....

 

You won't listen to reason

 

You're just ignorant

 

i tried being nice

I'm not arguing with you. It's fine. 

[maxsin72]

1 minute ago, Mistang said:

Ok sure, "you're wrong", good reply as any.

The cat is able to pull 12.5g, it has the capability but the risk is to damage slats, frame, intruments, etc

[Cab]

18 minutes ago, Mistang said:

That's different because the eagle simply has a limiter.

 

Anyway whatever I appreciate the effort but I still don't get why it would say the glove vanes allow 7.5g.

1. The F-15 does not have a limiter. The pilot can pull until he passes out or breaks the jet.

 

2. I think it implies the opposite. Without the glove vanes the F-14's max g at that speed would be less. If that's the case then the glove vanes might be called a g-enhancer.

 

Someone can correct me if I am wrong. 

 

In fact the first jet I can remember with an actual g-limiter was the F-16. 

Edited June 17, 2021 by Cab

[Mistang]

2 minutes ago, Cab said:

1. The F-15 does not have a limiter. The pilot can pull until he passes out or breaks the jet.

 

2. I think it implies the opposite. Without the glove vanes the F-14's max g at that speed would be less. If that's the case then the glove vanes might be called a g-enhancer.

 

Someone can correct me if I am wrong. 

The f 15 CAS has a limiter. This was already mentioned. 

[dundun92]

Just now, Mistang said:

The f 15 CAS has a limiter. This was already mentioned. 

at 12.5 Gs, not 9Gs

[Cab]

Just now, Mistang said:

The f 15 CAS has a limiter. This was already mentioned. 

I think it just warns the pilot, doesn't it? 

[Mistang]

1 minute ago, Cab said:

I think it just warns the pilot, doesn't it? 

Not sure.

 

from the dcs manual

 

 

included airframe improvements that increased G limits for production F-15A/B/C/D from 7 to 9 Gs,

[Cab]

1 minute ago, Mistang said:

Not sure.

 

from the dcs manual

 

 

included airframe improvements that increased G limits for production F-15A/B/C/D from 7 to 9 Gs,

Limits and a "limiter" are two different things.

 

Recommend you google "F-15 Overload Warning System (OWS)"

[ChockP51]

30 minutes ago, Mistang said:

Wikipedia implies they also limited g.

 

but we're attacking sources at this point.

 

my only question is did the tomcat ever hit 8g in real life? Was okie flying an A model when he made that claim and did he think it would matter?

What wikipedia imply is the pitching authority has been hamper by the aft shift in center of pressure due to shockwave in high speed flight (read above mach 1.5) on main wing and reduce pitch control power on the elevator itself due to the shockwave on elevator thus the elevator can’t really generate enough pitch control power to achieve 7.5G until glove vane was put in place. 
 

It doesn’t imply max G capability that airframe can generate.

[Mistang]

4 minutes ago, Cab said:

Limits and a "limiter" are two different things.

 

Recommend you google "F-15 Overload Warning System (OWS)"

https://www.military.com/video/military-aircraft-operations/aviation-accidents/f-15-in-flight-breakup/661029574001
 

the f15 might actually break apart at pretty low sustained g.

chock, thank you.

[jcdata]

No hard limiter on the 15 either.. like the 14..the limiter is the person yanking on the pole

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