F-14A/B Flight Model Tuning - Guided Discussion

[Vakarian]

Maybe it's not broken apart, but it's definitely broken

[Spurts]

3 hours ago, TotenDead said:

Iirc, the F-14 in the game can pull 12+G turns without breaking apart. Will that be fixed? I mean, it's only a 6.5G aircraft, its structual limit should be around 10Gs tops

this is a common misconception.  Grumman built the F-14 to be a 9.5G aircraft and tested it to 12 G. The Navy doesn't like anything more than 7.5G which was the initial NATOPS rating.  The Navy then lowered the NATOPS limit to 6.5G wartime and 5.5G peacetime for maintenance reasons but pilots still pulled 9-10+G when needed.  There are a handful of accounts of 12G pulls not breaking anything.  The G model HB is using is historically accurate.  Also, the design of the F-14 is such that if you are going fast enough to pull that high of G the wings are generally going to be swept which reduces the structural loads, and at lower speeds and altitudes where you may get high G with upswept wings the wing stalls and produces less lift above a certain angle of attack but the body lift compensates resulting is the normal force coefficient peaking around 30 AoA and not decreasing as AoA goes towards 90 (but as this is a normal force less and less is lift and more and more is drag)

Edited April 9 by Spurts

[TotenDead]

16 часов назад, Spurts сказал:

this is a common misconception.  Grumman built the F-14 to be a 9.5G aircraft and tested it to 12 G. The Navy doesn't like anything more than 7.5G which was the initial NATOPS rating.  The Navy then lowered the NATOPS limit to 6.5G wartime and 5.5G peacetime for maintenance reasons but pilots still pulled 9-10+G when needed.  There are a handful of accounts of 12G pulls not breaking anything.  The G model HB is using is historically accurate. 

 Hmm, but natops doesn't have a single word about peace/war time. It just states 6 Gs (or 6.5), some NATOPS write about some "projected limit", meaning that there were plans to increase the allowed G-load (probably after strengthening the construction, but that's just my guess)

 

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"Grumman built the F-14 to be a 9.5G aircraft and tested it to 12 G"

9.5G is weird, tbh. If that was a projected operational limit that would mean that the aircraft was overweight. However, that looks like the correct number for the structural limit if the max operational G-load is 6.5Gs.

When it comes to 12G, I believe that it's possible that some individual cases occured where the aircraft (either during ground tests or while being piloted by test pilots) pulled 12Gs in perfect conditions with minimal to no damage. But that doesn't really say that its structural limit is that high. What it might say though is that such aircraft as the F-15 might pull like 18Gs in similar conditions. Add some yaw or bank and the plane will break apart. That's what we don't have in DCS as far as I know
 

16 часов назад, Spurts сказал:

Also, the design of the F-14 is such that if you are going fast enough to pull that high of G the wings are generally going to be swept which reduces the structural loads, and at lower speeds and altitudes where you may get high G with upswept wings the wing stalls and produces less lift above a certain angle of attack but the body lift compensates resulting is the normal force coefficient peaking around 30 AoA and not decreasing as AoA goes towards 90 (but as this is a normal force less and less is lift and more and more is drag)

Well, since the aoa limit was 28 units (e.g 22 degrees) that looks like something very-very far from what service pilots could do. But anyway, that doesn't contradict what I wrote about perfect conditions pulls


Anyway, It would be really great to see any documentation about 9.5Gs you wrote about. So far all I could find stated only 6-7.5Gs

Edited April 10 by TotenDead

[draconus]

50 minutes ago, TotenDead said:

When it comes to 12G, I believe that it's possible that some individual cases occured where the aircraft (either during ground tests or while being piloted by test pilots) pulled 12Gs in perfect conditions with minimal to no damage.

Which means the airframe can survive that acceleration IRL so it's correctly implemented in DCS.

54 minutes ago, TotenDead said:

Add some yaw or bank and the plane will break apart. That's what we don't have in DCS as far as I know

Yes we do, and we lose wings in these cases.

[Spurts]

On 4/10/2025 at 10:57 AM, TotenDead said:

Well, since the aoa limit was 28 units (e.g 22 degrees) that looks like something very-very far from what service pilots could do. But anyway, that doesn't contradict what I wrote about perfect conditions pulls


Anyway, It would be really great to see any documentation about 9.5Gs you wrote about. So far all I could find stated only 6-7.5Gs

The AoA indexer goes to 28, and 28 may correlate to 22 degrees under certain circumstances, bit that is not the AoA limit of the F-14.  "F-14A High angle of Attack Characteristics" paper from August 1976 P.582 Figure 12 shows that max deflection of the horizontal tail results in pitch up moment just past 40 degrees, and P583 states "An unrestricted alpha capability does more than allow the pilot to generate superior levels of instantaneous g. Pilots have found that by flying above alpha=30 deg they effectively convert the aircraft into a flying speed brake.... Also, when flying in the high alpha region, the pilot finds it extremely easy to command the attitude changes required to point the aircraft at the target as he falls in behind his adversary."

I have several times in DCS reached 40 degrees AoA in hard pulls.

As to the 9+G stories, the book "Tomcat: Bye, bye, baby" has numerous accounts and the AIMVAL/ACEVAL reports show plots of how often the planes in that test exceeded 6, 7, 8, 9G

And the 12G pulls weren't test pilots, but operation pilots during both peacetime training scenarios and wartime scenarios.  The F-14 IS OVERBUILT as you mentioned it would be.  There is a reason it is so much heavier than everything else.  It is the heaviest CATOBAR aircraft ever.

Edited April 11 by Spurts

[cheezit]

1 hour ago, Spurts said:

[The F-14] is the heaviest CATOBAR aircraft ever.

The A3D was heavier (MTOW of 82,000 lb vs 74,000 and change as the final MTOW for the Tomcat), no?  And of course the F-111Bs that had some cat shots and traps during carrier suitability testing were much heavier - fair game not to count those since the aircraft (thankfully) never served!

 

[cheezit]

On 4/10/2025 at 10:57 AM, TotenDead said:

 Hmm, but natops doesn't have a single word about peace/war time. It just states 6 Gs (or 6.5), some NATOPS write about some "projected limit", meaning that there were plans to increase the allowed G-load (probably after strengthening the construction, but that's just my guess)

 

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"Grumman built the F-14 to be a 9.5G aircraft and tested it to 12 G"

9.5G is weird, tbh. If that was a projected operational limit that would mean that the aircraft was overweight. However, that looks like the correct number for the structural limit if the max operational G-load is 6.5Gs.

When it comes to 12G, I believe that it's possible that some individual cases occured where the aircraft (either during ground tests or while being piloted by test pilots) pulled 12Gs in perfect conditions with minimal to no damage. But that doesn't really say that its structural limit is that high. What it might say though is that such aircraft as the F-15 might pull like 18Gs in similar conditions. Add some yaw or bank and the plane will break apart. That's what we don't have in DCS as far as I know
 

Well, since the aoa limit was 28 units (e.g 22 degrees) that looks like something very-very far from what service pilots could do. But anyway, that doesn't contradict what I wrote about perfect conditions pulls


Anyway, It would be really great to see any documentation about 9.5Gs you wrote about. So far all I could find stated only 6-7.5Gs

 

Nearly everything you wrote here is wrong.  Do you have any books handy on the F-14's design, or are you limited to internet sources for the time being?  Ciminera's books would be useful in dispelling some of these notions, as would Cooper and Cooper/Bishop, for starters.  You could also look at HUD film of the F-14D air show demo if you find written sources un-credible want visual confirmation that an F-14 can hit 9.5 or 10g without spontaneously disassembling or bending like a coke can.

 

Incidentally, you did get one thing right - test pilots and Grumman did rate the F-14's effective G limits higher than fleet pilots (not to mention NATOPS) did!  Whereas the fleet pilots contented themselves with some 12G yanks and subsequent maintenance inspections revealing "not a bolt out of place" (a quote from CPT Keith "Okie" Nance), test pilots and Grumman instead considered the airframe to be either "symmetrically unlimited" or pilot-limited for symmetric pulls, due to the mechanism Spurts mentioned wherein the lifting body effect (remember the tunnel was a designed airfoil, not just a flat surface) relieved the wings at high AoA.

 

Of course, with an asymmetric pull you can over-G a Tomcat pretty easily, just as you can over-G a 9g-symmetric F-16 at 4g with an sufficiently asymmetric pull - generally the F-16 will yell at you before you get there, though!  This sort of thing is part of why the Air Force developed and installed/integrated an overload warning system before increasing the F-15's G-limit from 7.33 to 9 symmetric as part of the mid-1980s MSIP process.

[Spurts]

1 hour ago, cheezit said:

The A3D was heavier (MTOW of 82,000 lb vs 74,000 and change as the final MTOW for the Tomcat), no?  And of course the F-111Bs that had some cat shots and traps during carrier suitability testing were much heavier - fair game not to count those since the aircraft (thankfully) never served!

 

Looking over several variants of the A3D on Avialogs (https://www.avialogs.com/aircraft-d/douglas/itemlist/category/306-a-3skywarrior?start=12) shows that even as the weight increased with later variants the Max T.O. Cat weight doesn't exceed 73,000.  Not that I am finding anyway.  I never mind an honesty check if I ended up missing something.  You are right about the F-111B though, showing a near 78,000lb Max TO Cat weight.  I never consider it since it never went to service.

Edited April 11 by Spurts

[cheezit]

On 4/11/2025 at 5:41 PM, Spurts said:

Looking over several variants of the A3D on Avialogs (https://www.avialogs.com/aircraft-d/douglas/itemlist/category/306-a-3skywarrior?start=12) shows that even as the weight increased with later variants the Max T.O. Cat weight doesn't exceed 73,000.  Not that I am finding anyway.  I never mind an honesty check if I ended up missing something.  You are right about the F-111B though, showing a near 78,000lb Max TO Cat weight.  I never consider it since it never went to service.

My source for the 82,000 MTOW for the A3D was, sadly, the plane's Wikipedia article, which in turn claims to source it from the 1988 publication "McDonnell Douglas Aircraft since 1920: Volume I", which I do not own a copy of to check.  I see the same that you do looking at the 1967 SACs for the A3 variants (EA-3B, TA-3B, RA-3B, etc, but no KA-3B/EKA-3B) that the MTOW for a cat shot doesn't ever exceed 73,000 lbs and for land doesn't exceed 78,000 lbs - probably the 82,000 figure either is erroneous, or pertains only to the ~85 tanker/tanker+EW variants.

[WarthogOsl]

2 hours ago, cheezit said:

My source for the 82,000 MTOW for the A3D was, sadly, the plane's Wikipedia article, which in turn claims to source it from the 1988 publication "McDonnell Douglas Aircraft since 1920: Volume I", which I do not own a copy of to check. 

My copy of "The Encyclopedia of World Airpower" shows 82,000lbs, as does the appendix of Heater Heatley's "The Cutting Edge."

[PhantomHans]

On 4/11/2025 at 3:23 PM, cheezit said:

test pilots and Grumman instead considered the airframe to be either "symmetrically unlimited" or pilot-limited for symmetric pulls, due to the mechanism Spurts mentioned wherein the lifting body effect (remember the tunnel was a designed airfoil, not just a flat surface) relieved the wings at high AoA.

I think I saw video of an older guy talking about this but dont recall his name, but iirc he was a Grumman test pilot.  It makes me think that our HB F-14 may actually have too LOW of a symmetrical G limit before breaking!

[Spurts]

it used to be higher. You would get a series of systems failures before the wings came off. 20G ripping the engines from the mounts and shattering the INS but the wings remained.

[WarthogOsl]

13 hours ago, PhantomHans said:

I think I saw video of an older guy talking about this but dont recall his name, but iirc he was a Grumman test pilot.  It makes me think that our HB F-14 may actually have too LOW of a symmetrical G limit before breaking!

Probably Kurt Schroeder, as he's been interviewed a few times.  I think Dale Snodgrass (whose father worked at Grumman) also called it a 10G airplane.

[Bealdor]

10 hours ago, Spurts said:

it used to be higher. You would get a series of systems failures before the wings came off. 20G ripping the engines from the mounts and shattering the INS but the wings remained.

 

1 hour ago, WarthogOsl said:

Probably Kurt Schroeder, as he's been interviewed a few times.  I think Dale Snodgrass (whose father worked at Grumman) also called it a 10G airplane.

Should be episode 1 of the F-14 Tomcast.

[PhantomHans]

15 hours ago, Spurts said:

it used to be higher. You would get a series of systems failures before the wings came off. 20G ripping the engines from the mounts and shattering the INS but the wings remained.

Should it revert back to that?

 

Also I should start tracking how many Gs I'm actually pulling.  I probably rarely get close to 20 if ever.