G limits and Dogfighting

[Hummingbird]

Orders were as mentioned cut short, which is the reason for the 6.5 G operational limit. 

[GGTharos]

On 12/5/2020 at 5:36 PM, Hummingbird said:

All it needed to be certified for 9 G would be full orders, OWS and land based. No airframe reinforcement was necessary, the thing was already tougher than the F-15's until they were extensively modified in the 2000's with new tougher materials.

 

It's as tough as it was before, the new materials are there to prevent long-term problems and corrosion ... and given that the structural technologies were essentially the same, the F-14 would be suffering from the same issues.  This whole 'tougher' idea is entirely made up

[Hummingbird]

34 minutes ago, GGTharos said:

 

It's as tough as it was before, the new materials are there to prevent long-term problems and corrosion ... and given that the structural technologies were essentially the same, the F-14 would be suffering from the same issues.  This whole 'tougher' idea is entirely made up

 

If the new materials are there to prevent long term problems & corrosion, then they are by definition also tougher. Also last I checked we've come a loong way in metallurgy since the 70's.

[RaceFuel85]

On 12/5/2020 at 2:36 PM, Hummingbird said:

All it needed to be certified for 9 G would be full orders, OWS and land based. No airframe reinforcement was necessary, the thing was already tougher than the F-15's until they were extensively modified in the 2000's with new tougher materials.

This is pure unadulterated fantasy. 

 

[Hummingbird]

12 minutes ago, RaceFuel85 said:

This is pure unadulterated fantasy. 
 

 

No, as mentioned it featured the same ultimate load limit as the F-15 (infact it was a little higher), the big difference is that the F-14 had to operate from an aircraft carrier, which means a very corrosive environment and several high impact landings a day. Add to this that orders were cut short, and you end up with the reason for the 6.5 G peace time limit.

 

You can call that fantasy if you want, but from an airframe longevity POV it makes all the sense in the world.

Edited December 8, 2020 by Hummingbird

[Wizard_03]

4 hours ago, GGTharos said:

 

It's as tough as it was before, the new materials are there to prevent long-term problems and corrosion ... and given that the structural technologies were essentially the same, the F-14 would be suffering from the same issues.  This whole 'tougher' idea is entirely made up

I was wondering when you'd get here..

[FWind]

11 hours ago, GGTharos said:

 

It's as tough as it was before, the new materials are there to prevent long-term problems and corrosion ... and given that the structural technologies were essentially the same, the F-14 would be suffering from the same issues.  This whole 'tougher' idea is entirely made up

design limit seem 9 G in spectrum.

[GGTharos]

What are the graphs actually showing? 

[FWind]

1 hour ago, GGTharos said:

What are the graphs actually showing? 

[r4y30n]

design limit seem 9 G in spectrum.

Well, no... It says it was designed to survive hitting 9 g once, not on a regular basis.

[Wizard_03]

Based on these graphs the exceedes per flight hour above 7.5 is actually quite low, ~1/100 hours or less, that's not what I would call regular at all.  

 

Edited December 9, 2020 by Wizard_03

[FWind]

5 hours ago, Wizard_03 said:

Based on these graphs the exceedes per flight hour above 7.5 is actually quite low, ~1/100 hours or less, that's not what I would call regular at all.  

 

Another data from ACEVAL/AIMVAL

[Wizard_03]

So in Approximately 500 ACM engagements (31 hours) they recorded only 38 overloads beyond 7.5 and only 6 of those were in in the 9G range? Based on table 7 and Fig. 2 

 

These second charts were also specifically testing aircraft doing ACM practice. 

[FWind]

24 minutes ago, Wizard_03 said:

So in Approximately 500 ACM engagements (31 hours) they recorded only 38 overloads beyond 7.5 and only 6 of those were in in the 9G range? Based on table 7 and Fig. 2 

 

These second charts were also specifically testing aircraft doing ACM practice. 

Compared with F-15

Edited December 10, 2020 by FWind

[Wizard_03]

Is that with the OWS? 

[GGTharos]

It doesn't matter, it's a count of how many times whatever g's were exceeded and it's basically irrelevant to the 'this plane is tougher than that one' argument.   At the altitudes these guys are fighting at (ie. not on the deck, like every DCS dogfight) you're not going to pull 9gs anyway, bar some exceptions ... as demonstrated above.

 

So, none of this speaks to design limits or anything, and in particular if the aircraft is suspected to have a tiny number of 9g exceedance at 1h of flight and very rarely after, that's not really a 9g design.  So, I don't know what those graphs are showing other than 'we counted how many times a certain amount of g was exceeded vs flight hours' ... maybe I'm interpreting it all wrong.

Edited December 10, 2020 by GGTharos

[FWind]

6 hours ago, Wizard_03 said:

Is that with the OWS? 

Airframe maybe not have change when have OWS. Just about with crack growth analyses and strain.

[Wizard_03]

6 hours ago, FWind said:

Airframe maybe not have change when have OWS. Just about with crack growth analyses and strain.

I know but with OWS pilots are probably a lot less likely to overload the jet vs just the gauge. So that would affect the data. 

 

But either way, in regards the the F-14. it seems like overloads are a significantly less common then people make them out to be, based on that report. Taking the aircraft passed 7.5 is/was certainly a non standard practice in ACM. 

[henshao]

As it should be. The cat has more than enough capability at 7.5g to get the job done. It is really quite a lot of available G already, if you find yourself needing to exceed 7.5g, examine your tactics and see where the breakdown is. Surely you don't need more G BVR so if you're WVR needing more, try flying slower

[Reflected]

Check this interview with Shoes. At some point he tells a story about overstressing the airframe during a Topgun engagement, by a little more than a g IIRC. Based on his story:

- these were not common, you actually paid attention not to do it

- if you did it, there were consequences. IIRC he had to help the ground crew check every nut and bolt and make sure there was no damage

- There was no damage, Tomcats could withstand a lot higher g than what they were calibrated for

 

@IronMike maybe you could add some new Jester lines saying something like "ooh damn, I think we just overstressed the jet" or "Man, the ground crew will not be happy about that", or something like this when the player goes over the g limit for the given weight?

 

 

[Skysurfer]

6 hours ago, Reflected said:

 

@IronMike maybe you could add some new Jester lines saying something like "ooh damn, I think we just overstressed the jet" or "Man, the ground crew will not be happy about that", or something like this when the player goes over the g limit for the given weight?

 

 

 

I think this is a great idea. Say, if you bust 8G (to have some buffer) he'll make somre remarks about it. 

[Spurts]

Why not, he busts our chops about everything else (and we love him for it)

[Eagle7907]

Oooo...good idea. I like.

“(Grunt)....easy!....easy!”

After exceeding- “Aww man, the boss isn’t gonna be happy”

“(Strained voice) You alright?”

“Hey! What are you doing!” (Hehe)

The list goes on.



Sent from my iPhone using Tapatalk Pro

[Spurts]

"(Grunt) .... warn me next time man!"

[Uxi]

17 hours ago, Skysurfer said:

 

I think this is a great idea. Say, if you bust 8G (to have some buffer) he'll make somre remarks about it. 

 

Something about us messing up his spine, too.