F-14 performance discrepancies

[Hummingbird]

So I've discovered a rather massive discrepancy in the STR of the F-14 as altitude increases, at 15,000 ft for example I am only able to achieve a sustainable load factor of 3.4 G's @ 0.62 IMN in an F-14 with 4x AIM9 + 4x AIM7's and 50% fuel (55,600 lbs total), where'as the manual states 4.3 G's for the same weight, loadout, speed & altitude.

 

 

Considering people have been mentioning an inability to keep up with the F/A-18 in level flight at altitude I'm thinking this is a thrust related issue, and probably not drag a related one, but I can't be sure ofcourse.

 

So I'd probably advise Cat pilots out there to avoid dogfighting at altitudes above 5,000 ft for now until this is fixed.

Edited April 26, 2019 by Hummingbird

[Jowen G. Bruère-Dawson]

Thanks for sharing this !

[VampireNZ]

Yea - the 'Cat has seemingly been progressively nerfed power-wise since its first release.

Entered the vertical with an SU-27 at the same speed & G after the latest patch and it was clearly pulling away from me the whole way uphill (and carried on till about 100 knots...) like I was flying an L-39...

 

Rather interesting as all the RL Top Gun advice is to enter the vertical...

[Hummingbird]

I'm thinking it's an error in thrust degradation with increases to altitude, as the performance at SL feels accurate. It could ofcourse also be related to drag at specific AoA, but considering the authentic feeling performance at SL and a lot of people mentioning problems keeping up with other jets at altitude I'm suspecting it's a thrust issue.

[Eagle7907]

On a somewhat related, is the simulation correct for taxi thrust? That also seems a bit underpowered. Seems like the airplane weighs +100,000 lbs. To maintain taxi speed I have been having to set a constant 80-85%.

 

 

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[Dino Might]

There was a prior thread concerning this - the following is my interpretation, so forgive me if it is not entirely correct, but it is what I got out of the thread.

 

 

 

FM dependent on thrust and drag. They had things set to match B performance charts, even though drag (and consequently thrust) were not exactly right. In running the TF-30s, they recognized the incorrect airframe drag, so they revised it such that it would be more accurate and could be used to baseline both engines. Now the airframe drag model should be more correct, but the thrust for the GE engines on the B is not matched for the B performance charts yet.

 

It will be set right if it has not been done already. I can't remember if an expected date for new revisions on the thrust modeling would be finished for the B.

 

More than likely there will be some kind of iterative approach, as these things are not easy to nail down in one go even with extensive wind tunnel and flight test data.

It's also important to only change one set of variables at a time to be sure the correct behaviors and sensitivities are established, so the current mismatch is likely a necessary interim step.

Edited April 27, 2019 by Dino Might

[fat creason]

We are currently undergoing some thrust and drag tuning based on a new battery of FM tests we created. The tests were indicating we were overpowered but we quickly realized some of these tests were misleading in terms of specific excess power measurements. Increased thrust is coming as part of these ongoing changes as we get the model to match the excess power charts all the way from 1G flight up to 6.5G maneuvering flight.

 

Sometimes the iterative approach required to tune FMs causes things to get worse before they get better. Look for some handling qualities tweaks in the future as well. I’ll make a post detailing these changes when they’re complete.

Edited April 27, 2019 by fat creason

[Ala12Rv-watermanpc]

We are currently undergoing some thrust and drag tuning based on a new battery of FM tests we created. The tests were indicating we were overpowered but we quickly realized some of these tests were misleading in terms of specific excess power measurements. Increased thrust is coming as part of these ongoing changes as we get the model to match the excess power charts all the way from 1G flight up to 6.5G maneuvering flight.

 

Sometimes the iterative approach required to tune FMs causes things to get worse before they get better. Look for some handling qualities tweaks in the future as well. I’ll make a post detailing these changes when they’re complete.

 

Awesome!!, thanks!:thumbup:

[Hummingbird]

We are currently undergoing some thrust and drag tuning based on a new battery of FM tests we created. The tests were indicating we were overpowered but we quickly realized some of these tests were misleading in terms of specific excess power measurements. Increased thrust is coming as part of these ongoing changes as we get the model to match the excess power charts all the way from 1G flight up to 6.5G maneuvering flight.

 

Sometimes the iterative approach required to tune FMs causes things to get worse before they get better. Look for some handling qualities tweaks in the future as well. I’ll make a post detailing these changes when they’re complete.

 

Excellent :thumbup: Atm it feels exactly like that, i.e. a lack of thrust and an overabundance of drag at high AoA.

 

 

Any rough ETA on when to expect the next tweaks? :)

Edited April 27, 2019 by Hummingbird

[Jowen G. Bruère-Dawson]

Thanks Fat creason... Good luck with your work

[eatthis]

i had a drag race with an f18 on the deck both clean and i couldnt pull ahead at all lol surprised me!

[Eldur]

On a somewhat related, is the simulation correct for taxi thrust? That also seems a bit underpowered. Seems like the airplane weighs +100,000 lbs. To maintain taxi speed I have been having to set a constant 80-85%.

 

This is a general DCS issue... but more or less pronounced depending on the aircraft.

[Eagle7907]

This is a general DCS issue... but more or less pronounced depending on the aircraft.

 

 

 

Ah okay. Now that you mention it, you’re right. It seems all modules have this behavior all the way to the A10. It does seem more pronounced with the big cat.

 

 

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[eatthis]

On a somewhat related, is the simulation correct for taxi thrust? That also seems a bit underpowered. Seems like the airplane weighs +100,000 lbs. To maintain taxi speed I have been having to set a constant 80-85%.

 

 

Sent from my iPhone using Tapatalk Pro

 

check your parking brake isnt on

[Eagle7907]

Although would obviously be the problem, it’s not. Handle is in and light is off.

 

 

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[Davee]

Although would obviously be the problem, it’s not. Handle is in and light is off.

 

 

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Wheel brakes inverted in the "Controls/Axis" commands?

[Eagle7907]

Wheel brakes inverted in the "Controls/Axis" commands?

 

 

 

Nope. Because when I press down. The pedals in the sim go down. When released the mini hud show released. It’s not the brakes guys.

 

 

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[The Falcon]

So I've discovered a rather massive discrepancy in the STR of the F-14 as altitude increases, at 15,000 ft for example I am only able to achieve a......

 

.....So I'd probably advise Cat pilots out there to avoid dogfighting at altitudes above 5,000 ft for now until this is fixed.

 

 

Thx you so much, and thanks to people like you that this sim will be improved

[Buschwick]

So I've discovered a rather massive discrepancy in the STR of the F-14 as altitude increases...

 

...So I'd probably advise Cat pilots out there to avoid dogfighting at altitudes above 5,000 ft for now until this is fixed.

 

I agree. I've been flying flight sims over 20 years now and this is the most frustrating experience I've ever had. Seems like the cat weighs a million pounds while at full burner...and loses energy like it's a kite.

 

Shoulda waited.

[key_stroked]

I agree. I've been flying flight sims over 20 years now and this is the most frustrating experience I've ever had. Seems like the cat weighs a million pounds while at full burner...and loses energy like it's a kite.

 

Shoulda waited.

 

It was fine when they released it. But they swung the nerf bat too hard and neutered the cat. It needs its balls back.

[Hummingbird]

I really hope a fix will land tommorrow :)

 

I say this as I can't really bring myself to fly the Cat atm because of how massively it is underperforming, all your oppponent has to do is use the vertical and the game is basically over for the Cat.

[stuart666]

I dont think its that bad. Ive killed multiple F15's and F18's in multiplayer with it. That said its lost something at the bottom end. You used to be able to put it in mill power and 15 AOA and go around like a merry go round all day. Now, you really have to stick it in burner, and it bleeds energy fairly easy. Thinking about it, when you stuck your wings back, it was pretty reluctant to accelerate as well as it once did.

 

 

Still done the best with this one than any other play in multiplayer. I think the radar and the RIO still helps.

[Hummingbird]

I dont think its that bad. Ive killed multiple F15's and F18's in multiplayer with it. That said its lost something at the bottom end. You used to be able to put it in mill power and 15 AOA and go around like a merry go round all day. Now, you really have to stick it in burner, and it bleeds energy fairly easy. Thinking about it, when you stuck your wings back, it was pretty reluctant to accelerate as well as it once did.

 

 

Still done the best with this one than any other play in multiplayer. I think the radar and the RIO still helps.

 

It actually is quite bad, you don't have to go higher than 15,000 ft before sustained performance is ~25% under real life values, and the higher you go the worse it seems to get.

 

Hence training ACM with the aircraft atm doesn't really make much sense as it isn't possible to develop useful tactics when performance is that much lower than it should be.

 

Ofcourse you can still train landings, take offs, refueling and BVR (which is what I spent much of yesterday doing), but WVR ACM is not worth it atm.

 

But HB knows about the problem and will correct it, so all is good, I am just being impatient about getting my favorite toy back to full working order :D

[Brigg]

We are currently undergoing some thrust and drag tuning based on a new battery of FM tests we created. The tests were indicating we were overpowered but we quickly realized some of these tests were misleading in terms of specific excess power measurements. Increased thrust is coming as part of these ongoing changes as we get the model to match the excess power charts all the way from 1G flight up to 6.5G maneuvering flight.

 

Sometimes the iterative approach required to tune FMs causes things to get worse before they get better. Look for some handling qualities tweaks in the future as well. I’ll make a post detailing these changes when they’re complete.

 

Excellent news, thx fella:)

[stuart666]

It actually is quite bad, you don't have to go higher than 15,000 ft before sustained performance is ~25% under real life values, and the higher you go the worse it seems to get.

 

Hence training ACM with the aircraft atm doesn't really make much sense as it isn't possible to develop useful tactics when performance is that much lower than it should be.

 

Ofcourse you can still train landings, take offs, refueling and BVR (which is what I spent much of yesterday doing), but WVR ACM is not worth it atm.

 

But HB knows about the problem and will correct it, so all is good, I am just being impatient about getting my favorite toy back to full working order :D

 

 

 

 

I look at it from the point of view, the relative lack of power (because its either power or drag) is going to be a good primer for the A model when we get it.

 

 

 

I dont fly high so much, in multiplayer dominated by Aim9X and Aim120 there is no point. But I did manage to get it in the slot and stick the nose above the horizon, put it in 15AOA and burner, and brought it around to surprise an f15 that was all over me. I would agree that going vertical makes no sense at the moment. But in truth, im not sure it really makes sense against F18s armed with Aim9X anyway. Even a Mig29 got me that way.

 

 

 

I have to admit, ive not been flying it of late, simply because its such hard work. But it can be done, certainly against unimaginative pilots.