PSA: F-14 Performance/FM Development Status + Guided Discussion

[Victory205]

You were confused because I misspelled the acronym for Speedbrakes. If you retract either device once you start the approach turn, you’re going to struggle to get squared away. If it’s in the groove to catch a settle while slow and you have to go to mil, you won’t be able to recover and need to go around. You’ll probably already be waved off by paddles.

This will be far less of an issue in the A with the next hotfix. It didn’t happen often because pilots were generally squared away on approaches in the Fleet.

No tactile feedback for the AB zones from the throttles. You can feel them in the seat of your pants however due to longitudinal acceleration forces. 

[lunaticfringe]

12 minutes ago, Victory205 said:

No tactile feedback for the AB zones from the throttles. You can feel them in the seat of your pants however due to longitudinal acceleration forces. 

Thank you!

[Snappy]

Hello,

I just wanted to say thank you to Fat Creason and Victory205 for their continued huge efforts in further refining the flight model of the F-14. I have only an approximate idea how much testing , changing and re-evaluating is involved to get it within single digit or less percentage points of the available data while at the same time trying to make it respond correctly  and feel right according to the real pilot’s input on how the real aircraft flew.

So thank you both and everyone else involved with the FM very much!

 

Kind regards,

 Snappy 

Edited October 22, 2021 by Snappy

[Quid]

18 hours ago, Snappy said:

Hello,

I just wanted to say thank you to Fat Creason and Victory205 for their continued huge efforts in further refining the flight model of the F-14. I have only an approximate idea how much testing , changing and re-evaluating is involved to get it within single digit or less percentage points of the available data while at the same time trying to make it respond correctly  and feel right according to the real pilot’s input on how the real aircraft flew.

So thank you both and everyone else involved with the FM very much!

 

Kind regards,

 Snappy 

 

Hear hear!  Thank you very much to the team for all your hard work on this.

[Hummingbird]

Yup, their work is highly appreciated and admired!  (Often called the HB F14 the best module within DCS world, and for a reason) 

Also incase anyone wants to complain about how long it took:

1) It's no trivial matter, infact it's an insanely complex task to simulate real aero performance. So patience is required if you're expecting quality work. 

2) It took ED, a much larger team, even longer to start fixing the F16's FM. (mainly due to different priorities, but nontheless) 

 

So whilst I am quick to post my  test data amd feedback with every FM patch (like the Nov 2020 one), it's not out of slight or to criticize, but out of a desire to have help point out any potential issues the devs might have missed, and ensure the FM is as accurate as can be. I feel I have to do this due to my shared passion for these aircraft.

 

I also think most of the devs of DCS world, in the last few years, have begun to appreciate how passionate a lot of their costumers are about the modules performing precisely up to real life specs. As well as how highly revered they become when it is achieved. 

My hope is that eventually the FM will always be top priority amongst all devs within DCS world, as to me it is the most important aspect of any flight sim module. 

 

Edited October 22, 2021 by Hummingbird

[Lt_Jaeger]

I'm not very concerned if or if not the Tomcat can turn with x g for y minutes at z speed, I'm more interested if the real thing was really that twitching in the  pitch department. With the last change there is some new  "nervousness" around the pitch axis, which I find hard to anticipate.

On the other hand feels the plane far more stable in BFM.

I'm No pilot and no aeronautical engineer and English is definitely not my first language, so I find the new behavior hard to describe and just wonder if this is a interim thing or if we are really close t to the final state. 

[Callsign JoNay]

I don't feel the pitch nervousness, but I'm finding it harder to coordinate turns during routine cruising. My slip needle is all over the damn place.

[captain_dalan]

32 minutes ago, Callsign JoNay said:

I don't feel the pitch nervousness, but I'm finding it harder to coordinate turns during routine cruising. My slip needle is all over the damn place.

Me too, but still, i somehow like it. It will take some getting used to it, but in a good way. I actually got my first  level 3g turn 220ish nots without losing or gaining airspeed. The key is to keep her coordinated and i'm going to enjoy mastering that. 

BTW, just tested the F-14A at subsonic turning (3, 5 and 6.5g). I won't bother you with the details but it's as precise (if not more) as the F-14B. I was flying through the checkpoints inside 1-4 knots, which is beyond the precision of the table. Also, took the A up to 36000ft, with 2x AIM-54, 2x AIM-7M and 2x AIM-9L, and reached mach 2.06 or something. Didn't test accelerations, but top speed seems also fairly precise at this altitude. 

Didn't test transsonic and supersonic turning capability. That is more twitchy and will require more work, especially down low, where a slight bank change will take you to the drink.

[illegal1984]

Clearly better. Now, if I get dumb and slow the second guy kills me instead of the one I engaged. The way it should be. Kudos HeatBlur!

[SgtPappy]

14 hours ago, captain_dalan said:

Me too, but still, i somehow like it. It will take some getting used to it, but in a good way. I actually got my first  level 3g turn 220ish nots without losing or gaining airspeed. The key is to keep her coordinated and i'm going to enjoy mastering that. 

BTW, just tested the F-14A at subsonic turning (3, 5 and 6.5g). I won't bother you with the details but it's as precise (if not more) as the F-14B. I was flying through the checkpoints inside 1-4 knots, which is beyond the precision of the table. Also, took the A up to 36000ft, with 2x AIM-54, 2x AIM-7M and 2x AIM-9L, and reached mach 2.06 or something. Didn't test accelerations, but top speed seems also fairly precise at this altitude. 

Didn't test transsonic and supersonic turning capability. That is more twitchy and will require more work, especially down low, where a slight bank change will take you to the drink.

Yea, honestly, I can see how darn close this flight model is after using the scripted STR mission - my flying is so sloppy so I need to try more data points with less climbing and diving - but this should give a rough idea of how close Heatblur got the F-14A! I believe comparing it to the F-15 was folly as we had originally assumed that the F-15 was exactly matching its graphs.

 

Edited October 23, 2021 by SgtPappy

[maxsin72]

I must say, after many bfm matches, that new FM is much better than the old one. The plane is no more tanked and now is able to sustain turn rate at 300/350 knots IAS without losing speed. So i'm happy about that. I've also seen f14b top speed went from mach 2.2 to mach 2.1 and f14a top speed is mach 2.2 in quick mission free flight Nevada clean cfg (weapons and fuel tanks jettisoned) , so a bit far from mach 2.34. But globally the new FM is good. 

[draconus]

52 minutes ago, maxsin72 said:

The plane is no more tanked and now is able to sustain turn rate at 300/350 knots IAS without losing speed.

That's definition of str, right?

And last time I heard M2.34 was only achieved in a special test bird with manual intake geometry control.

[maxsin72]

4 hours ago, draconus said:

That's definition of str, right?

And last time I heard M2.34 was only achieved in a special test bird with manual intake geometry control.

Yes you are right, this is what we had not with the old FM. I've heard that with special F14 cfg they reached mach 2.5 and i've also read of someone who made a photo to the intake of one operational F14A and there was written mach 2.42. Mach 2.34 is for operational F14A.

I've also tested (free flight Caucasus) max sl speed: F14B a bit more than mach 1.1 (760 KIAS) F14A mach 1.25 (850 KIAS). Is it normal the F14B is so much slower than F14A at sea level?

P. S. i know tf30 has higher thrust at high mach number. 

Edited October 24, 2021 by maxsin72

[Panny]

With the old FM I managed to get to M 2.42 in the F-14A. I'll try again with new FM

[Hawkeye91]

Are the carrier catapult launch physics and post launch flight model accurate? I remember reading a few things from SMEs that the Tomcat was NOT a hands off aircraft like the F18 after a cat launch. In the F18, the FBW seeks the post launch AoA in combination with the trim setting. In the Tomcat, you're suppose to actually hand fly the plane off the deck once out of the shuttle. It seems the current iteration, it acts like an F18 on launch and hits that AoA on launch without the need for much input. Am I way off the mark here? Perhaps is a DCS core limitation like a lot of carrier related things are.

Edited October 25, 2021 by Hawkeye91

[Baz000]

Actually, I was wondering the same thing myself because after watching a lot of youtube of F-14 cat shots it looks like the stabs move to be what appears to be full deflection by I think the pilot. Furthermore, it looks like execution of pilot lateral stick motion (you can see spoiler movement) sometimes started while the plane is just at the end of the carrier deck is used to execute the clearing turn from the cat. I wasn't able to tell close enough if there was also a corresponding rudder deflection too. These pilot actions on launch seem to give the Tomcat a characteristic roll and yaw side slip look upon launch. Conversely, however in certain launch cases where an immediate clearing turn isn't performed by the pilot and departure is straight out climb. (I think in the movie The Final Countdown, you see such a launch by the Jolly Rogers alert flight)[you also see them ride the elevator up with pilots strapped inside and perhaps engines running, which IDK was done just for the movie or what... They also had their lights on which doesn't follow standard SOP]

Anyways, in the case of a straight out departure it looks like the Tomcat doesn't have that characteristic roll and yaw being so apparent which leads me to think this behavior is influenced by pilot flight control inputs.

But, I too was wondering the very same thing about the cat shot takeoff behavior... Oh, sometimes my pilot has a brief blackout too for some reason on a cat shot in DCS too.

[maxsin72]

Interesting story about max speed https://theaviationgeekclub.com/former-f-14-rio-tells-the-story-of-when-he-and-his-pilot-pushed-their-tomcat-beyond-the-aircraft-advertised-top-speed-of-mach-2-34/

 

 

Edited October 26, 2021 by maxsin72

[SgtPappy]

On 10/24/2021 at 8:25 PM, maxsin72 said:

Interesting story about max speed https://www.google.it/amp/s/theaviationgeekclub.com/former-f-14-rio-tells-the-story-of-when-he-and-his-pilot-pushed-their-tomcat-beyond-the-aircraft-advertised-top-speed-of-mach-2-34/?espv=1

 

 

Link is broken. This one should work: https://theaviationgeekclub.com/former-f-14-rio-tells-the-story-of-when-he-and-his-pilot-pushed-their-tomcat-beyond-the-aircraft-advertised-top-speed-of-mach-2-34/

[maxsin72]

7 minutes ago, SgtPappy said:

Link is broken. This one should work: https://theaviationgeekclub.com/former-f-14-rio-tells-the-story-of-when-he-and-his-pilot-pushed-their-tomcat-beyond-the-aircraft-advertised-top-speed-of-mach-2-34/

Thx for the update

[captain_dalan]

Has anyone taken the old lady through her paces above mach 0.8 down low yet? As in testing her above the peak Excess power? IS she close to the specs for 6.5, 5 and 3 at the top end?

Edited October 27, 2021 by captain_dalan

[fat creason]

Just a heads up, there are a few changes coming in the hotfix but I just barely missed the hotfix deadline with several more. Those changes and more will be in the next real patch.

[captain_dalan]

3 hours ago, fat creason said:

Just a heads up, there are a few changes coming in the hotfix but I just barely missed the hotfix deadline with several more. Those changes and more will be in the next real patch.

Roger that! When is the next hotfix scheduled for? 

[fat creason]

Based on the timing I want to say tomorrow or Friday but not totally sure...

Edited October 27, 2021 by fat creason

[Hector45]

5 hours ago, fat creason said:

Just a heads up, there are a few changes coming in the hotfix but I just barely missed the hotfix deadline with several more. Those changes and more will be in the next real patch.

I remember you guys mentioning ground roll physics were nearing completion, any update in that department?

[Callsign JoNay]

On 10/21/2021 at 10:24 AM, Hummingbird said:

I apologize for initially getting it wrong, I accidently tested at 400 KTAS @ SL when I should've been at 410 KTAS. I'm getting within 0.1 G at most speeds.

The devs did a great job on the FM.

 

So the consensus is the FM is almost right on the money for the A? Are there any diagrams to test against performance with Phoenix pylons?

I'm trying to figure out how their weight is modeled and I can't recall seeing an official hearblur answer. The rumor I've heard is that the weight and drag are modeled correctly, and rhe absence of gross weight change when they are removed in the ME is just a false indication (glitch) in the mission editor. However, I have never felt any additional sluggishness with the pylons attached, so I did a test last night on the most current open beta.

 

I tested 3 aircraft:

#1- An F-14B with empty Phoenix pylons and 8100 lbs fuel.

#2- An F-14B with no pylons and 8100 lbs fuel.

#3- An F-14B with no pylons and 10,300 lbs fuel. I chose this fuel quantity because as I understand it Phoenix pylons weight ~500 lbs each plus ~100 for each fairing.

 

Unlimuted fuel set in options so rhe gross weight stayed consistent through the test. I started at 500 feet sea level, 350 kts. Then I accelerated to 400 kts at full military power and began a smooth pitch up until wings symbol was 30 deg on the pitch ladder. I engaged attitude hold to minimize inputs that might cause inconsistent lift/drag. Then I held mil power until the aircraft dropped below zero on the VSI.

Both of the 8100 jets seemed to perform exactly the same, stalling out at 26,500 feet. The no pylon 10,300 jet stalled out 1500 feet below them at around 25,000 feet.

It seems to me that the weight of the pylons is not modeled. And the mission editor says a clean bird is 44,040 lbs which would seem to include the weight of the Phoenix rails according to publicly available info on the Tomcat's IRL gross weight. So it's confusing. Are the Phoenix rails weightless even though the ME says they weigh something? Is the gross weight as indicated in the ME inaccurate? It seems like it must be if the current FM matches the performance of the 4x AIM-7 4x AIM-9 loadout in the performance diagrams shared in this topic.

Video of my test below. Feel free to tell me if I screwed something up, or if any of your own tests indicate something different than mine. Just trying to get to the bottom of this.