FAQ for F-15 AFM Development

[FoxAlfa]

28 minutes ago, dundun92 said:

The GIF shows that high Gs break the netcode? Not sure how that is relevant to a FM discussion

You are well aware you can do that in SP too... Full Eagle.... 11,12g continuously.... with weight were charts say it can do 6.5-7.5g...

 

Also, ED stated it will be fixed... ppl here just like to delay the reality and maybe reduce the priority of the fix here by playing ignorant to the truth...

You will enjoy the Eagle more once it gets that limitation... capabilities make a nice game, but limitation make it a good simulation 

I for one know that I am enjoy the Viper more without the omnivision radar

Edited September 21, 2021 by FoxAlfa

[Cmptohocah]

From RL Eagle manual: max G load without stores for 10.000LB weight is 7.33G

 

Edited September 21, 2021 by Cmptohocah
Resized the image

[Rainmaker]

1 hour ago, FoxAlfa said:

You are well aware you can do that in SP too... Full Eagle.... 11,12g continuously.... with weight were charts say it can do 6.5-7.5g...

 

Also, ED stated it will be fixed... ppl here just like to delay the reality and maybe reduce the priority of the fix here by playing ignorant to the truth...

You will enjoy the Eagle more once it gets that limitation... capabilities make a nice game, but limitation make it a good simulation 

I for one know that I am enjoy the Viper more without the omnivision radar

 

 

Dont have a dog in the fight here...but I can almost make a guarantee that whatever chart you are trying to use to base the argument off of, is the wrong use of said chart. 

[FoxAlfa]

9 hours ago, Rainmaker said:

 

Dont have a dog in the fight here...but I can almost make a guarantee that whatever chart you are trying to use to base the argument off of, is the wrong use of said chart. 

Of course it is not the primary use of that chart... there is no chart that shows how a plane brakes up when you do stupid s**t that you shouldn't do since it destroys the airplane. 

 

With that said, Sustain Turn charts are good display of the aircraft G limits.... especially since they are factor of weight, and axis are G-load factor and speed.... and there is nicely marked area called 'Structural Limits'.

 

You can nicely see the F-15 at 44k lbs at sea level on standard day (15'c) can pull maximum of 8g, before Structal limit kicks in.

 

With that said you can comfortably pull 12g in 60k lbs F-15 in DCS, and ppl keep defending it by using one time story of somebody bending the frame to somehow prove that it can do that constantly and repeatedly.

 

If we applied their one-time rule, I guess 9x shouldn't be able to hit anything, but it doesn't work like that. 

 

I am for realism and standardisation of modeling, and if any aircraft has limits (and when it comes to Structal limits all of them have them) they should be simulated to some degree,

and if people are trying not to get them added, is just because they think they can abuse them to get advantage vs other players in some way, and that always requires a response. 

 

 

 

 

 

[draconus]

17 hours ago, Cmptohocah said:

I was talking with respect to DCS: all pilots have the same suits and same G tolerances.

Why would they have the same suits? They should not.

 

Quote

From RL Eagle manual: max G load without stores for 10.000LB weight is 7.33G

We need the "Note 1" for a clear picture on that limit but it's not structural - it's just max allowed (read safe). And the chart is not for 10'000lbs - it's for GW range of 30k to ~68k lbs. The bottom note says only about the GW unit of thousands lbs.

 

+1 for the Eagle's G-induced DM for the aircraft and stores.

Edited September 22, 2021 by draconus

[Rainmaker]

3 hours ago, FoxAlfa said:

Of course it is not the primary use of that chart... there is no chart that shows how a plane brakes up when you do stupid s**t that you shouldn't do since it destroys the airplane. 

 

With that said, Sustain Turn charts are good display of the aircraft G limits.... especially since they are factor of weight, and axis are G-load factor and speed.... and there is nicely marked area called 'Structural Limits'.

 

You can nicely see the F-15 at 44k lbs at sea level on standard day (15'c) can pull maximum of 8g, before Structal limit kicks in.

 

With that said you can comfortably pull 12g in 60k lbs F-15 in DCS, and ppl keep defending it by using one time story of somebody bending the frame to somehow prove that it can do that constantly and repeatedly.

 

If we applied their one-time rule, I guess 9x shouldn't be able to hit anything, but it doesn't work like that. 

 

I am for realism and standardisation of modeling, and if any aircraft has limits (and when it comes to Structal limits all of them have them) they should be simulated to some degree,

and if people are trying not to get them added, is just because they think they can abuse them to get advantage vs other players in some way, and that always requires a response. 

 

 

 

 

 

 

A. Structural limit also deals with service life. Not X time, or X number of times, or X time past X number of times. 
 

B. The OWS system on the real jet is way more in depth than the DCS implementation. The real jet has multiple accelerometers in multiple places. ‘Mass items’ vs ‘X’ items and what exactly sees 9G (or whatever G) dictates a lot of things. The charts are extremely simplistic, again, you are using them for something, or attempting to use, for something they were never intended to be used for.  There are actual books/criteria made for that purpose...we don’t in any way, use those -1 charts for anything not should they be nor was that the intent of them. 

Edited September 22, 2021 by Rainmaker

[Rainmaker]

3 hours ago, FoxAlfa said:

Of course it is not the primary use of that chart... there is no chart that shows how a plane brakes up when you do stupid s**t that you shouldn't do since it destroys the airplane. 

 

With that said, Sustain Turn charts are good display of the aircraft G limits.... especially since they are factor of weight, and axis are G-load factor and speed.... and there is nicely marked area called 'Structural Limits'.

 

You can nicely see the F-15 at 44k lbs at sea level on standard day (15'c) can pull maximum of 8g, before Structal limit kicks in.

 

With that said you can comfortably pull 12g in 60k lbs F-15 in DCS, and ppl keep defending it by using one time story of somebody bending the frame to somehow prove that it can do that constantly and repeatedly.

 

If we applied their one-time rule, I guess 9x shouldn't be able to hit anything, but it doesn't work like that. 

 

I am for realism and standardisation of modeling, and if any aircraft has limits (and when it comes to Structal limits all of them have them) they should be simulated to some degree,

and if people are trying not to get them added, is just because they think they can abuse them to get advantage vs other players in some way, and that always requires a response. 

 

 

 

 

 

 

BTW: Sustained turned rates are not a good way to do anything like that. Those turn charts are for sustained performance to project turn rates and capabilities of turn performance for a given airspeed/alt. Same scenario, you are improperly trying to make use of those charts for something for which that was never their intent. 

[FoxAlfa]

32 minutes ago, Rainmaker said:

 

A. Structural limit also deals with service life. Not X time, or X number of times, or X time past X number of times. 
 

B. The OWS system on the real jet is way more in depth than the DCS implementation. The real jet has multiple accelerometers in multiple places. ‘Mass items’ vs ‘X’ items and what exactly sees 9G (or whatever G) dictates a lot of things. The charts are extremely simplistic, again, you are using them for something, or attempting to use, for something they were never intended to be used for.  There are actual books/criteria made for that purpose...we don’t in any way, use those -1 charts for anything not should they be nor was that the intent of them. 

 

The point of that line on the chart is for the pilot to be aware there is a limit and that is the exact intent why it was used there, and again I am using it to show that there is a limit.  And I love to think that no body slapped that line there but used said books/criteria to place it there.

Edited September 22, 2021 by FoxAlfa

[GGTharos]

16 hours ago, Cmptohocah said:

From RL Eagle manual: max G load without stores for 10.000LB weight is 7.33G

 

 

 

This is the chart when the OWS is not operational or, before it was installed.  Again, let's be very clear that F-15s have been through multiple over-g incidents up to 12.5g.   Only one is known to have structurally failed because of over-g (as in disintegrated in mid-air) and the information on that incident is quite thin - IIRC the aircraft was fully loaded and attempted a high-g pull over the runway.   The 12.5g jet never flew again.   12 g was pulled in combat (not too much unlike the presented gif here) and flew again.

 

No amount of chart posting will take this fact away.

Edited September 22, 2021 by GGTharos

[FoxAlfa]

7 minutes ago, GGTharos said:

 

This is the chart when the OWS is not operational or, before it was installed.  Again, let's be very clear that F-15s have been through multiple over-g incidents up to 12.5g.   Only one is known to have structurally failed because of over-g (as in disintegrated in mid-air) and the information on that incident is quite thin - IIRC the aircraft was fully loaded and attempted a high-g pull over the runway.   The 12.5g jet never flew again.   12 g was pulled in combat (not too much unlike the presented gif here) and flew again.

 

No amount of chart posting will take this fact away.

 

You keep ignoring the fact that multiple well documented cased of F-15 crashing due to structural failure with two I posted from 2002 and 2007 being best known. 

[GGTharos]

11 minutes ago, FoxAlfa said:

You keep ignoring the fact that multiple well documented cased of F-15 crashing due to structural failure with two I posted from 2002 and 2007 being best known. 

 

Someone has already broken down the list in this thread.  I only know of two over-g incidents resulting in airframe write-off or disintegration.  That doesn't mean there aren't more, but they're not in your list.

 

Am I going to count the faulty longeron in?  Of course not, you've got no faulty aircraft spawning anywhere in this game, and this longeron didn't have an effect until the airframe was reasonably aged.

Edited September 22, 2021 by GGTharos

[Rainmaker]

9 minutes ago, FoxAlfa said:

You keep ignoring the fact that multiple well documented cased of F-15 crashing due to structural failure with two I posted from 2002 and 2007 being best known. 

Dude, I’m an F-15 maintenance person by trade. Jets were physically found to have structural defects. There were others found that might have gone years/decades before any catastrophic failure happened. It was a combination of a lot of things that attributed to those. I was intimately involved in those inspections personally as I was part of the cadre that tore jets apart to inspect them. You are using instances without context. 

1 hour ago, FoxAlfa said:

The point of that line on the chart is for the pilot to be aware there is a limit and that is the exact intent why it was used there, and again I am using it to show that there is a limit.  And I love to think that no body slapped that line there but used said books/criteria to place it there.

 

Again, you are implementing a line for something on a chart that was never intended to be used that way. You are trying to draw a line in the sand where there isn’t one. You are using the wrong charts and the wrong books for that. 

[FoxAlfa]

28 minutes ago, GGTharos said:

 

Someone has already broken down the list in this thread.  I only know of two over-g incidents resulting in airframe write-off or disintegration.  That doesn't mean there aren't more, but they're not in your list.

 

Am I going to count the faulty longeron in?  Of course not, you've got no faulty aircraft spawning anywhere in this game, and this longeron didn't have an effect until the airframe was reasonably aged.

 

Here are 3 more:
https://aviation-safety.net/wikibase/60356
https://aviation-safety.net/wikibase/70223
https://aviation-safety.net/wikibase/121265

[GGTharos]

You're trying way too hard.  None of these is over-g.

[FoxAlfa]

57 minutes ago, Rainmaker said:

Dude, I’m an F-15 maintenance person by trade. Jets were physically found to have structural defects. There were others found that might have gone years/decades before any catastrophic failure happened. It was a combination of a lot of things that attributed to those. I was intimately involved in those inspections personally as I was part of the cadre that tore jets apart to inspect them. You are using instances without context. 

 

You are missing the point of what I am trying to illustrate... I am trying to illustrate that F-15 like any other jet can be broken due to g... are you as F-15 maintenance person disagreeing with that fact?

And that those limits need to be added in DCS since it would make it a better simulation. How it is up to ED, for sure I am not fond of fixed numbers.

And don't get me wrong, nobody said ever it should be broken at exactly that limit... far from that, there are engineering safeties and for sure real plane can take way more... I am not even saying it can't take 12 g... because it can but there is danger in doing that... 

 

What I am saying that F-15 or for that fact any plane can't take continues -4.5 g to 12g to -4.5g transitions, things that no RL pilot would ever even think of doing, and that ED needs to add some way of stress simulation to the DCS F-15 since currently it is the only aircraft that doesn't have it.

 

 

Edited September 22, 2021 by FoxAlfa

[Rainmaker]

34 minutes ago, FoxAlfa said:

 

What I am saying that F-15 or for that fact any plane can't take continues -4.5 g to 12g to -4.5g transitions, things that no RL pilot would ever even think of doing, and that ED needs to add some way of stress simulation to the DCS F-15 since currently it is the only aircraft that doesn't have it.

 

 

 

 

I get your point completely...and I am not against the idea of doing such things (again, no dog in the fight)...it’s just the supporting elements that you guys have been using is not really suitable at all for the argument.  The instances of crashes, the charts, etc...are not related to the stance you are trying to give support to. 

[Rainmaker]

1 hour ago, FoxAlfa said:

Here are 3 more:
https://aviation-safety.net/wikibase/60356
https://aviation-safety.net/wikibase/70223
https://aviation-safety.net/wikibase/121265

The first 2, IIRC, were due to water intrusion. 
 

The third was the fault of the aircrew performing a bad escape maneuver with an improper weapons config. Zero to do with the aircraft itself. 
 

You are still way off. 

[nighthawk2174]

56 minutes ago, FoxAlfa said:

 

You are missing the point of what I am trying to illustrate... I am trying to illustrate that F-15 like any other jet can be broken due to g... are you as F-15 maintenance person disagreeing with that fact?

And that those limits need to be added in DCS since it would make it a better simulation. How it is up to ED, for sure I am not fond of fixed numbers.

And don't get me wrong, nobody said ever it should be broken at exactly that limit... far from that, there are engineering safeties and for sure real plane can take way more... I am not even saying it can't take 12 g... because it can but there is danger in doing that... 

 

What I am saying that F-15 or for that fact any plane can't take continues -4.5 g to 12g to -4.5g transitions, things that no RL pilot would ever even think of doing, and that ED needs to add some way of stress simulation to the DCS F-15 since currently it is the only aircraft that doesn't have it.

 

 

 

The effects of these are not going to be applicable on the time scale dcs simulates.  Dcs is not simulating how this one over-g may take a year or two off the airframes total decades long lifespan.  Or how small defects in manufacturing may cause some jets to need to be retired before others.  This is not something worth simulating or even possible in properly simulating.

[FoxAlfa]

36 minutes ago, nighthawk2174 said:

The effects of these are not going to be applicable on the time scale dcs simulates.  Dcs is not simulating how this one over-g may take a year or two off the airframes total decades long lifespan.  Or how small defects in manufacturing may cause some jets to need to be retired before others.  This is not something worth simulating or even possible in properly simulating.

It is not about F-15, it is about consistency, ether you have them for all or for none.

 

Limits have a tendency to get dangerous more and more you pushed them... I am pretty sure many RL jets won't see the wear and tear of DCS jets in whole lifetime... 

 

Pulling a great manevre feels much better when you know the limit is there, without it, pains me great to say, but flying the F-15 feels empty...

and seeing people who fly it online just to cheese the mechanic hurts its DCS reputation even more.   

  
Again, I like I think the HB solution for F-14, each time you spawn in... a random number from a range is generated... you don't know what it is... but you know it is there and it is going to bite you if you push to far. It is quite a nice and simple solution without going too deep in simulating stress on the structure and other details needlessly. 
 

 

 

 

 

Edited September 22, 2021 by FoxAlfa

[nighthawk2174]

10 minutes ago, FoxAlfa said:

It is not about F-15, it is about consistency, ether you have them for all or for none.

 

Limits have a tendency to get dangerous more and more you pushed them... I am pretty sure many RL jets won't see the wear and tear of DCS jets in whole lifetime... 

 

Pulling a great manevre feels much better when you know the limit is there, without it, pains me great to say, but flying the F-15 feels empty...

and seeing people who fly it online just to cheese the mechanic hurts its DCS reputation even more.   

  
Again, I like I think the HB solution for F-14, each time you spawn in... a random number from a range is generated... you don't know what it is... but you know it is there and it is going to bite you if you push to far. It is quite a nice and simple solution without going too deep in simulating stress on the structure and other details needlessly. 
 

 

 

 

 

 

Right except that (under normal circumstances) the F15 air frame cannot induce the g-loading needed to actual get into that range.  

[FoxAlfa]

34 minutes ago, nighthawk2174 said:

Right except that (under normal circumstances) the F15 air frame cannot induce the g-loading needed to actual get into that range.  

Nobody is asking for it to brake under normal circumstances or where it is not supposed brake, and in DCS for sure you can easily get it in that range...

high speed dive with high G pull per example 

Edited September 22, 2021 by FoxAlfa

[GGTharos]

13 minutes ago, FoxAlfa said:

Nobody is asking for it to brake under normal circumstances or where it is not supposed brake, and it DCS for sure you can easily get it in that range...

high speed dive with high G pull per example 

 

Which should allow you to get max 12.5g ... which did not break the aircraft.  This will be GW dependent but the point is this:  No one disagrees with you that over-g should break the jet under the right circumstances.  You're just not likely to encounter those circumstances if the jet isn't heavily loaded.

 

DCS allows you to pull more than 12.5g and the results of exceeding this should be very bad.  No one is arguing with you on that.

 

However, if you're thinking that an unsustained or even series of  high g-spikes are going to break the jet, you should be in for a bad surprise.   Likewise, people who load 3 bags and pull 13gs should be in for a bad surprise on the other side of the spectrum.

 

So let me repeat, and get this straight:  F-15s have been over-g'd up to 12.5g and only one over-g instance of many is known to caused catastrophic in-flight failure.

 

So does HB's solution apply reasonably to the eagle, if ED chose to do this?  Sure ... just at a higher value than you probably want it to.

Edited September 22, 2021 by GGTharos

[Cmptohocah]

8 hours ago, draconus said:

Why would they have the same suits? They should not.

Don't all DCS pilots have same tolerances? I was not aware of the fact.

 

8 hours ago, draconus said:

 

We need the "Note 1" for a clear picture on that limit but it's not structural - it's just max allowed (read safe). And the chart is not for 10'000lbs - it's for GW range of 30k to ~68k lbs. The bottom note says only about the GW unit of thousands lbs.

 

+1 for the Eagle's G-induced DM for the aircraft and stores.

 

My bad  on the weight as I was tired and didn't pay attention.
Not sure what "+1 for the Eagle's G-induced DM for the aircraft and stores." means.
 

4 hours ago, GGTharos said:

 

This is the chart when the OWS is not operational or, before it was installed.  Again, let's be very clear that F-15s have been through multiple over-g incidents up to 12.5g.   Only one is known to have structurally failed because of over-g (as in disintegrated in mid-air) and the information on that incident is quite thin - IIRC the aircraft was fully loaded and attempted a high-g pull over the runway.   The 12.5g jet never flew again.   12 g was pulled in combat (not too much unlike the presented gif here) and flew again.

 

No amount of chart posting will take this fact away.

 

Well, there you go: that's the cue for me to bug out. Charts mean nothing 'cause there was a RL Eagle that pulled 12+, 13+ and 12+G again and continued.
Complete waste of time from my side here as obviously official documentation means nothing.

BTW nominaly (by the charts) Flanker has 8G where as Eagle has only 7.33G limit, so I wonder when should the Flanker brake in DCS?
Anyway, it's not possible to have an argument when another side ignores facts, which are indisputable.
PS. Su internal components are tested 10x their rated G, so if something is rated for 5G, they test it up to 50G. But again, there's a reason why something is rated.
 

 

Edited September 22, 2021 by Cmptohocah

[GGTharos]

13 minutes ago, Cmptohocah said:

Well, there you go: that's the cue for me to bug out. Charts mean nothing 'cause there was a RL Eagle that pulled 12+, 13+ and 12+G again and continued.
Complete waste of time from my side here as obviously official documentation means nothing.

 

It just doesn't mean what you believe it means.  Ie. it's not any kind of structural strength document.   And not 'cause there was an eagle', there are GLOC studies showing multiple over-g incidents for the F-15, that being defined (IIRC) at 9g or more, with the number of incidents inversely proportional to severity.  Ie. there aren't a whole lot of 12g incidents, some more 11g incidents and most will be between 9 and 10.

 

13 minutes ago, Cmptohocah said:

BTW nominaly (by the charts) Flanker has 8G where as Eagle has only 7.33G limit, so I wonder when should the Flanker brake in DCS?

 

All aircraft are engineered to take x g at y GW, with a 30-50% margin.  The flanker breaks according to such a schedule, and you can pull 10g if you're light enough.  The eagle has a 9g limit when OWS is operative, and 7.33 when it is not ... why do you think that is?  The OWS doesn't do anything other than indicate your allowed g based on current conditions.

 

13 minutes ago, Cmptohocah said:

Anyway, it's not possible to have an argument when another side ignores facts, which are indisputable.

 

So why are you insisting on ignoring indisputable facts?  Eagle with OWS is a 9g aircraft.  Eagles have repeatedly exceeded the posted g tolerance without falling apart.

 

13 minutes ago, Cmptohocah said:

PS. Su internal components are tested 10x their rated G, so if something is rated for 5G, they test it up to 50G. But again, there's a reason why something is rated.

 

Yeah, but you're using reason x for purpose y instead of reason x for reason x.   No one is feeding you lies or trivial truths here, you're just stubbornly refusing to understand the error of your ways.

 

It seems like people are thinking the question is 'should the eagle break from over-g' ... but that's not the question.  It absolutely should, under the right conditions.  There's no over-g DM implemented for the eagle, nor other FC3 birds other than the flanker AFAIK.  I don't see anyone complaining that the MiG-29 won't break, or the A-10A or Frogfoot.   Or maybe my knowledge is out of date and those do break now.

 

And when ED does put this DM in, the flanker will still break when the eagle doesn't because hello, different airframes with different tolerances.

 

Edited September 22, 2021 by GGTharos

[dundun92]

17 minutes ago, Cmptohocah said:

Eagle has only 7.33G limit

That is not a structural limit though, that was an operational limit on early F-15As because of the lack of an over G warning system (the beeping the pilot hears at high Gs in the F-15C in DCS). With that its 9G rated, but again this is not a structural/engineering limit, this is purely an operational limit. Same thing with the 6.5 G F-14 limit.