14 hours ago, mSparks said:

then posted a chart showing the airframe can fail at 500KCAS

Bolded line in the diagrams? That's the max allowed speed with certain loadout that will limit performance (external tanks, X amount of missiles etc). Not a failure point.  1A is a totally clean aircraft, allowed to fly at 800 KCAS (but verified by test data to sustain 850KCAS)

Good luck with the email/tweet to Grumman,

2 hours ago, SAS443 said:

That's the max allowed speed

Also known as....

Never Exceed Speed (Vne)

Edited December 16, 20223 yr by mSparks

1 hour ago, mSparks said:

Also known as....

Never Exceed Speed (Vne)

Edit: You seem to have liked this post.......I think there's a risk you might be thinking that the facepalm is aimed at someone else than you......

Edited December 16, 20223 yr by 2reds2whites

At least we all agree now that Vne for structural failure is a true airspeed. I didn't think you would ever come around. I presumed thats why you facepalmed.

Edited December 16, 20223 yr by mSparks

 

 

2 hours ago, mSparks said:

At least we all agree now that Vne for structural failure is a true airspeed

 

 

Structural failure you say? So Every V-N diagram in the world is wrong?
You have unlocked the super-ultra secret by applying TAS?
Now will need to email alot more outlets than just Northrop Grumman. This is some nobel prize-feat happening right here at Avsim.

@Murmur, You are a reasonable individual.
Will you acknowledge his findings aswell? Because nothing beats a good peer-review of this groundbreaking thesis. Can we start applying TAS for V_ne in all "speed vs load factor" diagrams in litterature from now on. Thanks in advance.
PS: if you are short on time, a simple yes/no will suffice.
PS2:  Before you answer, just be aware of the opening parts of this thread (which coincidentally also would serve as a great opening to his nobel prize award speech)

On 12/14/2022 at 11:19 AM, mSparks said:

TBH, I make no claims to really having a clue about anything over a few thousand feet or a few hundred knots. This tomcat stuff is completely new to me, only time I ever put any time on a fast jet before now on a modern rig is Ace Combat 7 and those you get in the Battlefield series (and only then when someone stole my heli and I had to go sneak into the enemy spawn point to take theirs)

 

32 minutes ago, SAS443 said:

So Every V-N diagram in the world is wrong?

Just the bits I circled in red on yours maybe? Sounds like you're the one who feels they should be emailing Northrop Grumman... presumably right after you take an F14 out for a spin at 870kts IAS at 35,000 feet to prove it.

 

Edited December 16, 20223 yr by mSparks

2 hours ago, mSparks said:

Just the bits I circled in red on yours maybe?

No, that part was taken into account much earlier. 

On 12/14/2022 at 1:02 PM, SAS443 said:

Perhaps you should read up on what an indicated (or Calibrated) airspeed really is, and what VNE represents and why dense atmosphere is a limiting factor at low altitudes for reaching Mach 2.x or whatever you claim is possible

it's these bolded parts we are trying to make you understand (still, after 3 days and counting)

 

On 12/14/2022 at 11:19 AM, mSparks said:

moving into things I know even less about.

It looks like the F14 has a ~1400kts true airspeed limit, using 

https://aerotoolbox.com/airspeed-conversions/

1400kts CAS at 100 feet is mach 2.119

1400kts CAS at 30000 feet is mach 2.849

1400kts TAS at 100 feet is mach 2.117

1400kts TAS at 30000 feet is mach 2.376

You will not find 1.400 TAS nor CAS as for 100 feet MSL. It's impossible for the F14 to achieve. Not denying the fact we have a design limit speed at M1,75 / 870kts "indicated" at PA 15.000   (how big is the CAS-error of the F14 who knows)

Edited December 17, 20223 yr by SAS443

1 hour ago, SAS443 said:

impossible for the F14 to achieve

Because, as Murmur posted for us already - the engines cant take the temperature, not because the rest of the airframe cant take the air pressure/speed.

1 hour ago, SAS443 said:

it's these bolded parts we are trying to make you understand (still, after 3 days and counting)

its you that seems to not understand the difference between ias and eas/tas.

Vne is set less than the true airspeed the airframe fails at, but generally reported in ias or eas/cas (depending on whether the airframe can get to non trivial speeds at high altitude)

When you are low and slow it makes no difference, ias, eas,cas and tas are all basically the same.

get a bit higher and faster and you need to take into account for the fact ias is massively under reporting the true airspeed.

Get to F14 type speeds and its TAS all the way down to the point air density messes with the engines - where Vne reduces from around 1200-1400KTAS to ~800KTAS.

Edited December 17, 20223 yr by mSparks

3 hours ago, SAS443 said:

 

@Murmur, You are a reasonable individual.
Will you acknowledge his findings aswell? 

You are right of course, Vne and other envelope speeds are equivalent airspeeds, not true airspeeds.

39 minutes ago, Murmur said:

are equivalent airspeeds, not true airspeeds.

C172 Vne is 163KIAS.

because its airframe has been shown to withstand around 201KTAS (163KIAS at 14,000 service ceiling) + more than 10%

not

because its been shown to fail around 163KTAS (163KIAS at 1,000 foot) 

Edited December 17, 20223 yr by mSparks