F-35A maximum G rating lower than 5?!

Discuss the F-35 Lightning II
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quicksilver

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Unread post12 Feb 2020, 20:09

Ref the Colonel — Ahh, I did see that. I have no problem with it.

Those kinds of comments are not unusual as units and individuals transition from one type to another. In this case, they were made before he had even flown the new jet.

It’s kinda axiomatic that pilots love most (and forever) the jet that they loved first. And in an aircraft transition, everything new is often the source of considerable discomfort because what was once so familiar and reflexive in the old jet is now unfamiliar in the new one, requiring consciously deliberate thought and action to do the most routine things. New flight equipment, new helmet, new way to strap in, new hotas, new displays and symbology, new switchology, new sounds. In many ways ya gotta go back to being a newb and that’s not just very, very uncomfortable, it’s unsettling to many. They get over it as everything becomes more practiced and familiar, and they establish proficiency in the new jet.

It’s also very typical to hear, ‘I don’t like this...I don’t like that’ about the new jet — not necessarily because it’s bad, but rather because it’s different and unfamiliar. Eventually, like the Major in the podcast, they learn to appreciate what the new thing does much, much better.
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steve2267

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Unread post12 Feb 2020, 20:17

QS, maybe you can answer this question for me. If it's too complicated, just say so.

Two hypothetical planes, say at 15k ft:
  1. Aircraft A can sustain 7g @ 450kts (0.8 Mach) (+/-) yielding about 15°/sec
  2. Aircraft B can sustain 5.5g @ 375kts (06.65 Mach) (+/-) giving the same rate of 15°/sec

Is this contest, from a turning perspective anyway, a wash? I see that Aircraft A has an advantage in energy a bit, but Aircraft B will be flying a smaller radius. I am thinking Aircraft A needs to go to Plan B.

If, when unloaded, Aircraft B can accelerate as fast as A, perhaps even faster, then I'm unsure that initial energy advantage A has would be of much use if he decided to try to go vertical. If B can also outpoint A when speeds drop off... then I think A is in trouble.

Am I tracking here?

If true, it is, in a nutshell I think, why the F-35 is so dangerous and why even the Bee with its "7g limit" is so dangerous as well.
Take an F-16, stir in A-7, dollop of F-117, gob of F-22, dash of F/A-18, sprinkle with AV-8B, stir well + bake. Whaddya get? F-35.
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basher54321

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Unread post12 Feb 2020, 20:22

steve2267 wrote:I am going to say yes... until... the ANG Blk42's got the PW-229EEP motor. Using the uninstalled thrust from the acceptance test, and running numbers on the actual aircraft, it is my understanding these Blk42's had the highest TW ratio of all Vipers then in service. (Perhaps a good question would be if the Blk 30's were in service at the time the Blk42's got their -229EEP motors?



Fat chance based on the 42s weight given in the early 90s manual. Yes Block 30s are still in USAF front line service albeit very upgraded. No what would be more interesting is to see if the GE-100 actually puts out more dynamic thrust over the PW-229 in places. :P
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steve2267

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Unread post12 Feb 2020, 20:35

basher54321 wrote:
steve2267 wrote:I am going to say yes... until... the ANG Blk42's got the PW-229EEP motor. Using the uninstalled thrust from the acceptance test, and running numbers on the actual aircraft, it is my understanding these Blk42's had the highest TW ratio of all Vipers then in service. (Perhaps a good question would be if the Blk 30's were in service at the time the Blk42's got their -229EEP motors?



Fat chance based on the 42s weight given in the early 90s manual. Yes Block 30s are still in USAF front line service albeit very upgraded. No what would be more interesting is to see if the GE-100 actually puts out more dynamic thrust over the PW-229 in places. :P


Will have to take your word for it. http://www.f-16.net/f-16_versions.html has the Blk30 and Blk42 both with an empty weight of 18,238lb. Oh, well.
Take an F-16, stir in A-7, dollop of F-117, gob of F-22, dash of F/A-18, sprinkle with AV-8B, stir well + bake. Whaddya get? F-35.
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Unread post12 Feb 2020, 20:40

basher54321 wrote: Now what would be more interesting is to see if the GE-100 actually puts out more dynamic thrust over the PW-229 in places. :P

From the charts I see in the old HFFM pdf, the -229 had SOME areas of advantage over the -100, but that was all at the far right end of a given altitude.
For example at 40,000ft
The -229 shows rising through 14,000lbt at 1.4M, cresting around 17,500 at 1.75M, then back down to 14,000 at 2.1M.
The -100 shows rising through 14,000lbt at 1.3M, cresting around 19,000 at 1.65M, and dropping to 14,000 by 1.9M.
I don;t know if this was a CFD and thermal model or if they were able to get actual data.
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Unread post12 Feb 2020, 20:42

Steve, all that goes into understanding where and how ones jet fights best before one ever gets in the jet for one’s first bfm ride.

One of my favorite observations about teaching bfm was the search for keys that would unlock someone’s understanding. For some, quantifiable parameters helped most; ‘pull your nose up between 30 and 40 degrees until you see... then roll 90 degrees etc. For others, word pictures and use of stick models. Some just needed to see it in the jet; all the academics in the world weren’t gonna do. Everyone’s brain was a little different when it came to developing understanding and proficiency in bfm. Some who were very good in everything else simply couldn’t process the dynamics of maneuvering in 3D space.

So, your quantifiable example doesn’t consider maneuver in three dimensions — two aircraft engaged in fluid and highly dynamic out-of-plane maneuvering.

I think what makes any fighter dangerous in bfm are those performance characteristics that generate rapid/superior ‘rates of change‘ in three-dimensional space for positional advantage or weapons employment relative to an adversary.
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steve2267

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Unread post12 Feb 2020, 20:55

quicksilver wrote:Steve, all that goes into understanding where and how ones jet fights best before one ever gets in the jet for one’s first bfm ride.

One of my favorite observations about teaching bfm was the search for keys that would unlock someone’s understanding. For some, quantifiable parameters helped most; ‘pull your nose up between 30 and 40 degrees until you see... then roll 90 degrees etc. For others, word pictures and use of stick models. Some just needed to see it in the jet; all the academics in the world weren’t gonna do. Everyone’s brain was a little different when it came to developing understanding and proficiency in bfm. Some who were very good in everything else simply couldn’t process the dynamics of maneuvering in 3D space.

So, your quantifiable example doesn’t consider maneuver in three dimensions — two aircraft engaged in fluid and highly dynamic out-of-plane maneuvering.

I think what makes any fighter dangerous in bfm are those performance characteristics that generate rapid/superior ‘rates of change‘ in three-dimensional space for positional advantage or weapons employment relative to an adversary.


Copy, thanks.
Take an F-16, stir in A-7, dollop of F-117, gob of F-22, dash of F/A-18, sprinkle with AV-8B, stir well + bake. Whaddya get? F-35.
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Unread post12 Feb 2020, 20:57

sprstdlyscottsmn wrote:From the charts I see in the old HFFM pdf, the -229 had SOME areas of advantage over the -100, but that was all at the far right end of a given altitude.
For example at 40,000ft
The -229 shows rising through 14,000lbt at 1.4M, cresting around 17,500 at 1.75M, then back down to 14,000 at 2.1M.
The -100 shows rising through 14,000lbt at 1.3M, cresting around 19,000 at 1.65M, and dropping to 14,000 by 1.9M.
I don;t know if this was a CFD and thermal model or if they were able to get actual data.



Good point thanks.
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Unread post12 Feb 2020, 20:59

ON previous page JPGs of five pages of an AirForces Monthly Nov 2019 story 'BADGER AIR MILITIA' was posted - now below.
Attachments
Badger Air Militia AirForces Monthly Nov 2019 pp5.pdf
(1.04 MiB) Downloaded 234 times
A4G Skyhawk: www.faaaa.asn.au/spazsinbad-a4g/ & www.youtube.com/channel/UCwqC_s6gcCVvG7NOge3qfAQ/videos?view_as=subscriber
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Unread post12 Feb 2020, 21:22

steve2267 wrote:QS, maybe you can answer this question for me. If it's too complicated, just say so.

Two hypothetical planes, say at 15k ft:
  1. Aircraft A can sustain 7g @ 450kts (0.8 Mach) (+/-) yielding about 15°/sec
  2. Aircraft B can sustain 5.5g @ 375kts (06.65 Mach) (+/-) giving the same rate of 15°/sec

Is this contest, from a turning perspective anyway, a wash? I see that Aircraft A has an advantage in energy a bit, but Aircraft B will be flying a smaller radius. I am thinking Aircraft A needs to go to Plan B.

If, when unloaded, Aircraft B can accelerate as fast as A, perhaps even faster, then I'm unsure that initial energy advantage A has would be of much use if he decided to try to go vertical. If B can also outpoint A when speeds drop off... then I think A is in trouble.

Am I tracking here?

If true, it is, in a nutshell I think, why the F-35 is so dangerous and why even the Bee with its "7g limit" is so dangerous as well.


A couple more thoughts —

Situational timing (the geometry) of any given maneuver/counter relative to one’s adversary can be all-important. For example, if I already have 3/9 control inside the adv’s turn radius, I may want to use the ability to very rapidly shrink my turn radius (‘rapid change’) in-plane to park in my adversary’s control zone, and still have enough energy to point and kill or force him back down if he makes a move in the vertical.
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steve2267

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Unread post12 Feb 2020, 21:37

quicksilver wrote:
A couple more thoughts —

Situational timing (the geometry) of any given maneuver/counter relative to one’s adversary can be all-important. For example, if I already have 3/9 control inside the adv’s turn radius, I may want to use the ability to very rapidly shrink my turn radius (‘rapid change’) in-plane to park in my adversary’s control zone, and still have enough energy to point and kill or force him back down if he makes a move in the vertical.


Am unfamiliar with the phrase "3/9 control" -- are you on your adv's 3-9 line (or close to it) and pointed at your adv (or close to it)?

How do you "force your adv back down" if he decides to go vert? Is this where all-aspect, HOBS heaters like AIM-9x come into play? "Sure, go vert, see what I care, as soon as I get my nose around, you're toast..." ?

AIM-9x et al shirley have complicated the game, haven't they?
Take an F-16, stir in A-7, dollop of F-117, gob of F-22, dash of F/A-18, sprinkle with AV-8B, stir well + bake. Whaddya get? F-35.
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Unread post12 Feb 2020, 21:51

steve2267 wrote:
Am unfamiliar with the phrase "3/9 control" -- are you on your adv's 3-9 line (or close to it) and pointed at your adv (or close to it)?

How do you "force your adv back down" if he decides to go vert? Is this where all-aspect, HOBS heaters like AIM-9x come into play? "Sure, go vert, see what I care, as soon as I get my nose around, you're toast..." ?

AIM-9x et al shirley have complicated the game, haven't they?


3/9 = behind his wing-line

Force him down? ‘Point’; he has to honor my nose position or he dies sooner rather than later.

Of course, this is all ‘classic’ bfm, and to arrive at an in-plane control zone I’ve already flown through a whole bunch of the missile’s employment envelope.
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Unread post12 Feb 2020, 21:57

steve2267 wrote:
How do you "force your adv back down" if he decides to go vert?


Speaking from a sim perspective, sometimes as I get position on an enemy plane it goes vertical. I need to be aware of my energy state, nose position, distance, low speed behavior, and other enemies in order to decide what to do next.

Examples of gunshots
I'm in an F-14 at 0.6M, half a mile separation, and am still 30 degrees off from putting the guy in my hud. I can roll vertical to follow and pull ~2/3 stick to put him in my hud by the time I am coming over the top. The enemy now has to dive to get away from me assuming I don't pop him near the top.

I'm in an F-14 at 0.5M, a mile separation, the guy was almost in my hud when he went up. If I pull 2/3 stick to vertical the deflection angle will be too high and I may lose visual. If I pull to keep him in view I will overshoot and I don't have the speed to go beyond about 1/2 stick pull. I cannot threaten him worse than a brief raking snapshot.. He has the option to roll out at the top and go horizontal, my energy will be low no matter what I do and I will be using rudders to turn.

I'm in an F/A-18, anything over 200KIAS, any distance within a mile, any angle within 30 degrees, no other enemies. Grip it and rip it. I have gone over the top at 37KTAS feeling like I'm in full control and nearly 1,000ft below the enemy plane, but all the enemy saw is during his entire vertical maneuver I had my nose on him so he dives to get his energy back to turn.

Same as above but another enemy at play. Abort. Go horizontal to try and catch him on the back side or disengage altogether. Do not go vertical with a starting speed under about 300KIAS or else I will get splashed.
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Unread post12 Feb 2020, 22:19

Thanks all.

QS, was there ever a point in time during the F-35 development, when you read or heard something and realized or decided right then that "Well, I'll be... LM got it right... this thang is going to be a beast to be reckoned with..." ?
Take an F-16, stir in A-7, dollop of F-117, gob of F-22, dash of F/A-18, sprinkle with AV-8B, stir well + bake. Whaddya get? F-35.
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Unread post12 Feb 2020, 22:48

steve2267 wrote:Thanks all.

QS, was there ever a point in time during the F-35 development, when you read or heard something and realized or decided right then that "Well, I'll be... LM got it right... this thang is going to be a beast to be reckoned with..." ?


I never thought it would be anything but a beast. I knew/know some folks who flew the X-jet and others who are familiar w its development, DT and fleet intro.
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