Highway to physical reality

[lunaticfringe]

20 minutes ago, Mistang said:

That doesn't help, it's still within the 7.5 limit Grumman gave.

You've been making the argument in this thread for two days, and a week in your previously deleted thread, that the Tomcat blows up in excess of 6G.  Now you move the goal posts when disproven by your inability to perform basic math.  

You're trolling, and you're not even competent at it. 

Closing time, everybody.  Last one out, turn off the lights. 

 

[Mistang]

2 minutes ago, lunaticfringe said:

You've been making the argument in this thread for two days, and a week in your previously deleted thread, that the Tomcat blows up in excess of 6G.  Now you move the goal posts when disproven by your inability to perform basic math.  

You're trolling, and you're not even competent at it. 

Closing time, everybody.  Last one out, turn off the lights. 

 

I don't see how you proved your point. But ok.

[lunaticfringe]

6 minutes ago, Mistang said:

I don't know where your 430 knot number came from. Can you just show math?

The video, had you watched it. 

Edited August 30, 2022 by lunaticfringe

[Mistang]

3 minutes ago, lunaticfringe said:

The video, had you watched it. 

 

I did watch it. Please don't be obtuse. Are you reading the gauges or something?

 

He does say "430 knots" when leveling out but nothing like saying that is what he was actually reporting as the current speed.

Edited August 30, 2022 by Mistang

[lunaticfringe]

16 minutes ago, Mistang said:

I did watch it. Please don't be obtuse. Are you reading the gauges or something?

 

He does say "430 knots" when leveling out but nothing like saying that is what he was actually reporting as the current speed.

 

He reported "430 knots, cans are off, you're fast" at 2:57.  He began the level out at 3:08.  That is, he was in that pull the entire time, while you claim he was leveling when he made said call.

You have nothing to resort to except the falsification of what is put in front of you, as though the rest of us aren't watching the same footage. 

Nah, man- he's saying "430 knots" like it's just a topic of conversation to help make the time go by with his RIO.

Again- sus. 

Edited August 30, 2022 by lunaticfringe

[Mistang]

3 minutes ago, lunaticfringe said:

He reported "430 knots, cans are off, you're fast" at 2:57.  He began the level out at 3:08.  That is, he was in that pull the entire time, while you claim he was leveling when he made said call.

You have nothing to resort to except the falsification of what is put in front of you, as though the rest of us aren't watching the same footage. 

Nah, man- he's saying "430 knots" like it's just a topic of conversation to help make the time go by with his RIO.

Again- sus. 

 

I am not satisfied with your argument and it seems to be circumstantial. I will allow you to have that point and end the discussion if that is all. 

[LanceCriminal86]

Weird, Hultgreen's jet was very much intact and did not disintegrate before impacting the water, nor was any "over-g" attributed to the incident, rather a compressor stall due to high AOA and low airspeed with heavy rudder input last I recalled. Where's the proof for your assertion there OP?

[lunaticfringe]

23 minutes ago, Mistang said:

I don't see how you proved your point. But ok.

Considering your attempt at the math, that's understandable. 

[Mistang]

2 minutes ago, LanceCriminal86 said:

Weird, Hultgreen's jet was very much intact and did not disintegrate before impacting the water, nor was any "over-g" attributed to the incident, rather a compressor stall due to high AOA and low airspeed with heavy rudder input last I recalled. Where's the proof for your assertion there OP?

That maintenance documentation wouldn't be available. I am merely showing the possibility that it happened.

[BIGNEWY]

guys this thread isnt going anywhere, not seeing any evidence to support the claims in detail.

[LanceCriminal86]

3 minutes ago, Mistang said:

That maintenance documentation wouldn't be available. I am merely showing the possibility that it happened.

No, you are not. You threw a crash out there that was gone over 2-3 times by the Navy itself and inquiries as having nothing to do with G-stress, and everything to do with known weaknesses in the TF-30 at high AOA and low airspeed, and where a pilot exhibited old habits that worked fine in the Prowlers that she was an excellent pilot in, but was deadly in the Tomcat. The jet was recovered and Gs had nothing to do with it.

[Mistang]

49 minutes ago, BIGNEWY said:

guys this thread isnt going anywhere, not seeing any evidence to support the claims in detail.

I can actually calculate the rivet strength and end it conclusively if you accept that.

 

First off, it depends entirely on materials. The tomcat that existed on the drawing board was much more capable than the one that actually existed. So if you are going for technicalities any turn rate is possible and this discussion doesn't mean anything. If you are winning on technicalities the debate is over. If you are going by reality then saying stuff like "the tomcat can turn 7g for a full minute" is impossible.

So a f 14 for example has a 3m wing length from front to back. It has a 1m diameter. The rivets are a cm and are spaced to cover about 10% of the plane. So a 3 m wing with 2 sides with rivets every 10 cm is 30 rivets. That's 300 grams of steel or 300 mpa of tensile strength.

A plane turning 1000 m/s with ten tons is 100 gigawatts which will easily destroy these rivets. The actual aircraft has a 10 meter radius so this would be about 20 turns a second or 7,000 degrees. The stress needs to be 3000 times less or 50 times slower. That's 140 degrees a second. With weaker steel and smaller rivets you get the actual turn rate of 30 degrees a second. Note that the turn rates already given above are in this range. 

As you can see as the plane gets bigger all these values get worse and an an225 cannot complete a standard rate turn and do an air show. Adding weight reduces the turn rate.

What I am saying is that turn rate is a cumulative function. Pulling infinite G for an instant is always possible, the only meaningful model is where the stress on the airframe accumulates rather than "you can always turn X g" like in a video game. In reality even a 2g turn is impossible for more than a few minutes. 

The FAA on its website says it handles 5000 flights per hour, this is a lie. Flight trackers show far less. Planes do not fly 200,000 hours. They fly about ten hours and turn a few seconds before being destroyed. It's not "lifecycle preservation", planes are a throwaway expendable equipment unlike the car you drive.

There is no objection possible to this post because it just frames the problem. This is a conclusive end to the discussion, if you have any objection to specific parameters those are their own thread.

If you say something like "the plane can sustain a 7g turn for a full minute" or can sustain repeated turns that add up to that, then you are wrong. That is categorically false given the rivet strength. Anything below that gets uncertain and "YouTube says this". 

G limit is not a fixed value per time, it's a damage function that accumulates. Not over a long time but within a single flight. The exact way this happens requires a extremely advanced engineering simulation that will never happen but something like "50% destruction odds after 1 minute of 7g" is totally accurate and extremely generous. 

Edited August 30, 2022 by Mistang

[lunaticfringe]

9 minutes ago, Mistang said:

I am not satisfied with your argument...

Take it up with physics. 

9 minutes ago, Mistang said:

...and it seems to be circumstantial.

All those noted circumstances, and yet, the one in your contention has never taken place.  

6 minutes ago, Mistang said:

That maintenance documentation wouldn't be available. I am merely showing the possibility that it happened.

The maintenance documentation was discussed in the accident report. You're not showing a possibility, you're stating it as fact, and expecting everyone else to disprove your nonsensical contention that you support with a ridiculously poor grasp of the concepts and math involved.  This is quite literally devolving into flat earthism on your part. 

5 minutes ago, BIGNEWY said:

guys this thread isnt going anywhere, not seeing any evidence to support the claims in detail.

For clarity, which claims?  The math confirms one set of claims. Footage reinforces said arguments. 

[Frosty2124]

36 minutes ago, Mistang said:

I don't see how you proved your point. But ok.

I think the issue some people have is that you're unable to prove your point with solid irrefutable evidence. If could provide some that would be most helpful

[Quid]

14 hours ago, Mistang said:

Finally an effort post, thank you.

I don't actually have access to cite 1 and it seems to be out of stock. However I will reproduce your g limit graph here in the attachments.

It clearly says a 7.5g limit and I don't see the 9g claim supported anywhere, in any documentation. In fact the information you cited directly refuted your own claim.

Your Snort citation clearly says that he lost an engine (you didn't mention that) and it was a hard turn for the aircraft. Nothing like a "routine" event. Your other sources are either brief or give similar comments. Again you are directly refuting your own point and proving a 10g turn will destroy the aircraft.

You also didn't mention the error in the G gauges. If you wish I can cite error ranges on modern gauges, and the tomcat error would be worse. The Grumman number of 7.5 G is the actual number and anything else can be considered erroneous. Why would you trust YouTube over technical documentation, especially when these are casual interviews that say the plane was destroyed anyway? 
 

You also avoided the central point, which is the amount of time. In video games the turn rate is a fixed amount and you pull it forever. In reality these are obviously brief episodes and none of your examples were more than a second. So using your 8.5 mention and a 10% error that's actually what Grumman gave, and your remaining citations all destroyed the aircraft in less than a second.

So everything you cited directly proves my point and refutes your own. The tomcat is a 6g plane and can pull more for a fraction of a second, and snodgrass and other tomcat pilots confirm the plane is destroyed beyond that. This is all in your own citations, and directly refuted your own point, you just did not read your citations.

 

EDIT by Bignewy - removed picture as it was a document newer than 1980

Man, this is a great trolling effort!  I don't think you understand what the word "refute" means, nor the context to which I responded.  You claimed that the F-14 can't go above 6g without disintegrating, in spite of its NATOPS limit (6.5g), Grumman's ultimate "g" of +13g, Grumman's safe operating envelope of +9g/-5.5g (or +8g with a 6-2 loadout with tanks), Grumman's design target (7.5g), or any of the real-world examples I provided where the plane was brought to beyond +12g symmetrical with no ill effect to the airplane, or the ACEVAL/AIMVAL data which showed that during a sliver of that exercise, the plane averaged beyond 7g about 3 times per hour of flight.  Therefore, your claim is refuted.  I myself never made any claims apart from a response to your 6g claim.  The fact that you are now using 7.5g is itself an acceptance that your original claim was refuted.

The fact that a TF-30 stalled in an asymmetrical 9-10g barrel roll is irrelevant to your initial argument.  The plane was fine, Snort got the engine restarted.  Also, I provided rough amounts of time, but just to amplify in Hoser's case, he brought the jet from 600 to under 200 and by the time Hawk reacquired him, Hoser already had the landing flaps down (Hoser used landing flaps consistently in a slow-speed fight in the F-14), so he was above your supposed 6g max for several seconds.  This is covered in Hawk's biography which I cited.

All of the other things which you bring up do nothing to help your original argument.  Your claim is refuted, good Sir, and there is no reason to waste any more time with a troll.  This actually reminds me of that scene from "Kung Pow: Enter the Fist" - "I'm bleeding more, that means I win!"

[MiG21bisFishbedL]

53 minutes ago, Mistang said:

That maintenance documentation wouldn't be available. I am merely showing the possibility that it happened.

You're not showing a possibility, but rather asserting it as theory, theory without a studied body of facts that support it. Also, we have video of the incident in question. What we see is a clear power failure, not structural. We also have voice records of Hultgreen being told to raise her gear and add power. At no point do we see any portion of the F-14's wing or structure separate from the rest of the airframe. All of this would lead one to infer that F-14 BuNo. 160390 suffered loss of power in one engine, was subjected to the subsequent asymmetric thrust, and subsequently resulted in the roll over we see.

Edited August 30, 2022 by MiG21bisFishbedL

[JupiterJoe]

Some of the knowledge on show in this thread is dazzling.  Proud to be a part of this community.  Some of those videos you guys shared were awesome.

Edited August 30, 2022 by JupiterJoe

[Machalot]

1 hour ago, Mistang said:

A plane turning 1000 m/s with ten tons is 100 gigawatts

This is nonsensical.  It has nothing whatsoever to do with the kinetics of a turning aircraft. And the math is wrong. 

[Mistang]

Just now, Machalot said:

This is nonsensical.  It has nothing whatsoever to do with the kinetics of a turning aircraft. And the math is wrong. 

Could you be more specific?

[Jayhawk1971]

[Mistang]

1 minute ago, Jayhawk1971 said:

I made a minor error but it doesn't change the point.

[lunaticfringe]

1 hour ago, Mistang said:

A plane turning 1000 m/s with ten tons is 100 gigawatts which will easily destroy these rivets.

A plane turning 1000 m/s is doing roughly 1940 knots, or just under Mach 3.

Edited August 30, 2022 by lunaticfringe

[Mistang]

1 minute ago, lunaticfringe said:

A plane turning 1000 m/s is doing roughly 1940 knots, or just under Mach 3.

 

That's fine. Make it mach 2, it barely changes the result.

[FWind]

[Mistang]

5 minutes ago, FWind said:

That's a good way to express it. The tomcat can turn 100 "exceedances" (not clear what an "exceedance" entails) at 9g. Furthermore this is without any load or structural weight.

Edited August 30, 2022 by Mistang