[RESOLVED] FM: Sinks to much during bank & groove.

Latest OB.

Standard CASE I, during abeam turn & in the groove (trap config. DLC in/out. speed-brk out, <54k ibs, 30° bank. On AoA). F-14 looses a lot of lift.

Since 2 updates I/we noticed a high sink rate during the abeam turn & when in the groove. Forcing to use excessive afterburner use, resulting in very unstable approaches & wave-off's.

Most noticeable during: ISA +5, wind 0kt, Carrier-speed 25kt.

Less, but still noticeable during: ISA +5, H-wind 15kt, Carrier-speed 10kt.

Seems like turning abeam into a x-wind & then a head-wind "helps" with the lift, which shouldn't be a factor, if at the same IAS/AoA.

I think HB should check what's going on with the "lift-FM" in land.config when there is & isn't wind involved.

I filed a bug 2 days ago they are investigating as they had already noticed something wrong.

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I hope they get it sorted soon. The Tomcat was a dream to fly a few updates ago, but I've had to put a lot of my video projects on hold because its handling around the boat is just too awful now.

This flight model constant tuning seems so weird. At the beginning it was the rocket ship as it should be, then it was nerfed to lazy. Now it's better and still people complaining about it. How are we suppose to know how the Tomcat should fly?

I hope they get it sorted soon. The Tomcat was a dream to fly a few updates ago, but I've had to put a lot of my video projects on hold because its handling around the boat is just too awful now.

I completely agree. The big FM patch about a month ago made an already very likable aircraft a dream to fly around the boat. Stable in AOA and very responsive to throttle changes with lots of power in reserve. But since the latest patch the handling in the pattern and in the groove is just awful.

Just to clarify guys: What we noticed is, that it seems as after a sortie the weight might not get deleted, or for some reason the drag of the expanded payloads remains. Which then results in excessive use of power.

However the stability has increased in the latest patch. If I fly a case 1 mission (like form instant actions), I have no issue whatsoever with sinking, banking or excessive throttle work, it is pretty much a solid 3 wire all way through, just yesterday I tested a couple case 1s again. 800 stable level through the break, good drop and lift reaction with gear and flaps, drop to 600 with dlc, easily got it on speed, 450 in the 90 - all pretty much without breaking a sweat.

One thing what the latest patch introduced due to the increased stability is a much more direct stick input. So if you had previously your curves set too high, this will like result in the aircraft actually feeling less stable than it was. The delayed inputs also might cause a bit out of configuration approach, which results than in counter actions like excessive throttle work or power requirements.

A good test for example is lowering the curves to 0, or even trying with a minimal negative curve (max like -3 I would suggest), and see if you gain more control back and feel more stability.

The better the stick, the less curves you should need and less deadzones as well. Please try and see if that helps. Thank you.

I have a floor mounted T-50 with a long extension and fly with 0 curve. My previous experience (before last week's patch) was that after trimming to on-speed in the downwind, basically no more stick input in pitch was required for wings-level flight. For the base turn some back stick was required to stay on-speed AOA, but once rolling out in the groove I would basically let go of the stick (except to control roll) and fly the ball with throttle. Once trimmed, the aircraft was very stable in staying on-speed even with power changes. This seems no longer possible.

Just to clarify guys: What we noticed is, that it seems as after a sortie the weight might not get deleted, or for some reason the drag of the expanded payloads remains. Which then results in excessive use of power.

 

However the stability has increased in the latest patch. If I fly a case 1 mission (like form instant actions), I have no issue whatsoever with sinking, banking or excessive throttle work, it is pretty much a solid 3 wire all way through, just yesterday I tested a couple case 1s again. 800 stable level through the break, good drop and lift reaction with gear and flaps, drop to 600 with dlc, easily got it on speed, 450 in the 90 - all pretty much without breaking a sweat.

 

One thing what the latest patch introduced due to the increased stability is a much more direct stick input. So if you had previously your curves set too high, this will like result in the aircraft actually feeling less stable than it was. The delayed inputs also might cause a bit out of configuration approach, which results than in counter actions like excessive throttle work or power requirements.

 

A good test for example is lowering the curves to 0, or even trying with a minimal negative curve (max like -3 I would suggest), and see if you gain more control back and feel more stability.

 

The better the stick, the less curves you should need and less deadzones as well. Please try and see if that helps. Thank you.

What about the DLC behavior? Prior to the recent updates DLC would increase/decrease sink rate with very minimal AoA change--perhaps one or two degrees. In the current version, extending DLC causes AoA to increase excessively. Stowing DLC respectively causes an excessive decrease in AoA as well. When I say "excessive," I mean in comparison to previous iterations of the flight model.

I tested a couple case 1s again. 800 stable level through the break, good drop and lift reaction with gear and flaps, drop to 600 with dlc, easily got it on speed, 450 in the 90 - all pretty much without breaking a sweat.

Have you tried CASE I, with 0 wind & boat doing 25-30kt? The "sinking" is very noticeable in this condition.

The better the stick, the less curves you should need and less deadzones as well. Please try and see if that helps. Thank you.

I tested & I see no difference in different curves. IMHO it's about the FM's, lift, drag & power-response in land-config. /Thank you.

What about the DLC behavior? Prior to the recent updates DLC would increase/decrease sink rate with very minimal AoA change--perhaps one or two degrees. In the current version, extending DLC causes AoA to increase excessively. Stowing DLC respectively causes an excessive decrease in AoA as well. When I say "excessive," I mean in comparison to previous iterations of the flight model.

Agreed. There is a 4kt increase to AoA speed with DLC active. Why the excessive AoA changes?

And that the DLC disconnects all the time due to need of afterburner use doesn't make it easier.

Have you tried CASE I, with 0 wind & boat doing 25-30kt? The "sinking" is very noticeable in this condition.

Carrier speed and WoD have zero influence on your turning performance.

I never have to use anything near full MIL in the pattern. Even at max trap weight with full fighter loadout, 5500-6000 PPH is enough to stay on AoA with a slight descend (200-300fpm). I don't want to step on anyone's toes but the problem may be more user (pilot) related. The Tomcat needs increadibly smooth power and pitch inputs in the pattern, otherwise you will find yourself overcorrecting the whole time. Low AoA situations are especially dangerous. A few degrees above optimum will require a significant thrust addition to get back on AoA, maybe even full MIL or AB.

Just to clarify guys: What we noticed is, that it seems as after a sortie the weight might not get deleted, or for some reason the drag of the expanded payloads remains. Which then results in excessive use of power.

Thats interesting. I did get the impression that after finishing a sortie firing off all my missiles and being rather light (about 48k lbs), I needed more thrust in the pattern than I'm used to when flying clean from the start. Maybe it wasn't my imagination after all

Carrier speed and WoD have zero influence on your turning performance.

RL yes. But this is DCS & you never know what buggs out next?: https://forums.eagle.ru/showthread.php?t=122387 so you see wind/no wind has been bugged before & it screwed up the FM's for +7 months.

Do the test & you'll see a difference (wind 0kt, Carrier-25kt, & H-wind 15kt, Carrier-10kt.).

Also If you fly the same CASE I mission, with same winds, time after time, chances are you'll never notice this, but if you change winds you'll see.

Do the test & you'll see a difference (wind 0kt, Carrier-25kt, & H-wind 15kt, Carrier-10kt.).

Just tested under the following conditions:

54000lbs

Tanks+2SW+3SP+2PH

40°C, 28.10 inHg

This is as bad as it gets considering landing weight, drag and ambient conditions.

I tried with both zero wind and 25kts carrier speed and 10kts wind and 15kts carrier speed.

No difference between the above. In both scenarios, I was able to maintain 15 AoA and a slight descend of about 200-300fpm, even at 30° AOB.

Power settings where quite high but still not full MIL (See screenshot for engine params). Again, this was the worst case scenario. With lower temperature/higher pressure, power setting in the turn is nowhere near full MIL.

I'm sorry but the problem is on your end not HB's.

54000lbs

Tanks+2SW+3SP+2PH

40°C, 28.10 inHg

This is as bad as it gets considering landing weight, drag and ambient conditions.

I tried with both zero wind and 25kts carrier speed and 10kts wind and 15kts carrier speed.

No difference between the above. In both scenarios, I was able to maintain 15 AoA and a slight descend of about 200-300fpm, even at 30° AOB.

Power settings where quite high but still not full MIL (See screenshot for engine params). Again, this was the worst case scenario. With lower temperature/higher pressure, power setting in the turn is nowhere near full MIL.

I'm sorry but the problem is on your end not HB's.

40°C is normal in summertime in PG region. Today's Dubai Int. METAR: OMDB 151200Z 29011KT 200V330 CAVOK 38/24 Q0995 NOSIG.

Your pic shows the power very near MIL, there's very little leverage room. If you're to low after 90, what happens then? You'll be most likely in MIL. I would think the F-14 has enough power even at your extreme density-alt. condition.

EDIT/ Just tested your scenarios & I was in MIL allot. It wasn't much different from 20C/STD. The F-14 feels under-powered in land.config. IMO.

It's not only me, look at the thread. All guys in my squad have the same opinion, some even call it a sinking brick now. :music_whistling:. I wouldn't go so far, but it's definitely not at all pleasant to fly around the boat now.

Guys read IronMikes post whatever you take off with is your landing weight. Yes it sinks like a brick cos the game thinks you weigh 70+tonnes.

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Guys read IronMikes post whatever you take off with is your landing weight. Yes it sinks like a brick cos the game thinks you weigh 70+tonnes.

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IronMikes's bug explanation is not effecting my tests AFAIK.

My tests are done in air-start behind the carrier, or launching from it, bellow max trap-weight.

Hmm interesting I have only found a problem when I have a heavy launch weight. So IronMikes explanation worked for everything I had seen. Launching semi light and hitting a tanker makes it handle ok, tho I did have the engines flame out when I tried to defuel to 4000lbs which seems like a big but not one worth reporting as wth would want to defuel a full jet to 4k lol for some reason it emptied the main tanks 1st flamed out both engines genes went offline doh. So I kicked my squad mates from the server and edited the loading , bug solved

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I would think the F-14 has enough power even at your extreme density-alt. condition.

Well it has, I was a little overpowered when the screenshot was taken, so it should have been more like 96% N2. Thats not much power left but still enough IMO. In the F-14A however, things will look different.

It wasn't much different from 20C/STD.

I have to disagree on this one. In standard conditions, power requirements are significantly lower (about 2-3% less N2), giving you a comfortable power reserve in the turn.

If you're to low after 90, what happens then?

A few percent more N2 and a little less bank will arrest the sinkrate to zero.

All in all, the current FM may be a little underpowered in low density conditions, but its not "sinking like a brick" and there is no need for MIL power. In the above conditions however, there is little room for errors in power/AoA management.

Guys read IronMikes post whatever you take off with is your landing weight. Yes it sinks like a brick cos the game thinks you weigh 70+tonnes.

Interesting, I haven't tested that scenario. FWIW, flying in MP and taking off with 70klbs, I have no problems getting back to the boat. I will do a test in more controlled conditions though.

I did have the engines flame out when I tried to defuel to 4000lbs

WING/EXT TRANS switch in OFF?

My flameout was in a hot jet trying to get the weight down to 58k. Just using the rearm refuel window.

I definitely feel the weight as described by Ironmike. We just hit the tanker after takeoff yesterday on Hoggit but still ended up doing a speed brakes in DLC out pattern.

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Thank you for all your further reports, please know that we do not dismiss any of your impressions and take all viewpoints seriously. We will keep investigating this, but from a developer perspective, all we did over the past couple months is increase performance. Which is what leads us to think that this might be generally a weight/drag related issue. We already inquired with ED about it and hopefully we can find a solution soon.

This is one of the issues very much at the forefront of our minds. However with parts possibly being out of our hands, please understand that it might take a while to find both the true cause and solution.

Your reports do help us a lot, so if you obeserve anything further related to this, please let us know. Thank you.

Our FM tests have not indicated any loss in performance or aircraft drag changes over the past month. These tests run within our own testing framework and not DCS, so newer changes to DCS may not be reflected in our testing environment. If anything, the Tomcat's performance has only been increased in the past 4-6 weeks. We're investigating and working with ED to figure out what's going on, as it certainly seems to fly with decreased performance in-game all of a sudden.

The interface between our FM code and DCS physics is mainly forces and moments, not including the forces/moments from ground reactions and stores. We have very limited control over those two areas as they are calculated by DCS before it all goes into the equations of motion.

We have a few theories as to what's going on, since our testing framework may not be in sync with potential ED changes to the areas mentioned above:

1. Gross weight is somehow not being calculated properly when fuel/stores weight changes.

2. Stores drag model needs more investigation, with certain loadouts/configurations we suspect there are drag discrepancies.

If gross weight is higher than it should be on the DCS side of the fence, the aircraft will need to fly at a higher AoA and airspeed to generate enough lift, resulting in more drag and more power needed. Right now we're seeing lower climb rates in-game as well as sluggish acceleration in BFM and too much power needed around the boat in certain stores/fuel configurations. This could be related to weight, drag, or both, but it's hard to tell since everything looks unchanged in our testing environment.

Once we can get a response from ED we will provide an update.

Your reports do help us a lot, so if you obeserve anything further related to this, please let us know. Thank you.

Once we can get a response from ED we will provide an update.

Thank you! to both of you & good luck with the debugging :thumbup:.

I glad to here other people are experiencing the same as I am. I was beginning to think I was losing the little touch I had trying bank and get in the groove on speed.

Ok, disregard my last posts. After some more testing I found serious issues with the FM, namely when taking off from the carrier vs airstart.

I did five flights, all with the same ambient conditions. In these flights, I tried to stay level and on AoA (15 units) in landing config (gear DN, flaps full, spoilers full, DLC on)

1st flight: TO from CV with Tanks+2SW+4PH, 20klbs fuel >70klbs weight

Barely kept level flight in landing config at 99% N2, 8200PPH and 165kts

2nd flight: Airstart with Tanks+2SW+4PH, 20klbs fuel >70klbs weight

Comfortably kept level flight at 96% N2, 7000PPH and 150kts

3rd flight:TO from CV with Tanks+2SW+4PH, 20klbs fuel, then expanded all missiles and burned fuel down to 4000lns > weight 47klbs

Level flight maintained at 95% N2, 6900PPH and 145kts (Note, approach speed for that weight should be 128kts)

4th flight: Airstart with tanks and rails only and 4000lbs fuel > weight 47klbs

91% N2, 4900PPH and 128kts (spot on NATOPS)

5th flight Airstart with Tanks+2SW+4PH, 20klbs fuel, then expanded all missiles and burned fuel down to 4000lns > weight 47klbs

Same as 4th flight.

It appears that whenever you start from the carrier, weight and/or drag are too high, even from the very start, as can be seen by the difference in required engine power between the 1st and 2nd flight.

With that in mind, I definetly agree with the OP that the FM has issues, I just don't believe they are wind related but rather a problem with ground start weight/drag calculation

I see this is marked as both BUG and DCS BUG. Which part is DCS bug? I have noticed that since the updates the QNH is no longer correct. For example all of my missions where QNH is 29.92, I must dial my altimeters to 30.03 or 30.04 to read proper field elevation. Did ED mess with the atmospheric modeling again and screw up FMs?

I see this is marked as both BUG and DCS BUG. Which part is DCS bug? I have noticed that since the updates the QNH is no longer correct. For example all of my missions where QNH is 29.92, I must dial my altimeters to 30.03 or 30.04 to read proper field elevation. Did ED mess with the atmospheric modeling again and screw up FMs?

Well that's...interesting. Could be related; but if it is, it would be affecting more than the tomcat FM.