F18C Sustained Turn Rate

[wilbur81]

A quick post as a reference:

There is a fair bit of misinformation floating about regarding the DCS Hornet and it's Sustained Turn Rate (over) performance in the form of user created EM diagrams, Youtube videos, etc. I submit that ED has pretty much nailed it. Here is a completely slick Hornet with 60% internal gas, at near-sea level, through a few max G turns...But keep in mind, I've flown these WITHOUT the paddle switch employed, as a real USN Hornet would be (and which would be reflected in real world EM performance charts) flown, real world. This is obviously only one, non-extensive, test, but you get the picture. The paddle makes a fairly significant difference.

Max sustained turn rate in this test was 18.5 Deg per sec. These were all max stick deflection pulls, in full AB. You can definitely get the little chart at bottom left to read higher in the 23-24 deg per sec range, but if you actually watch the live "object box", those dps are not sustained but momentary, and at low airspeeds... which makes the chart itself a bit misleading. Truly sustained, after testing both the Viper and the Hornet, the Viper has a consistent 1.5-2 deg per sec. sustained advantage when watching the live object box in TacView.

STR - Slick Hornet - SeaLvL.trk Tacview-20240402-215526-DCS-STR - Slick Hornet - SeaLvL.zip.acmi

Edited April 3, 2024 by wilbur81

[HWasp]

10 hours ago, wilbur81 said:

A quick post as a reference:

There is a fair bit of misinformation floating about regarding the DCS Hornet and it's Sustained Turn Rate (over) performance in the form of user created EM diagrams, Youtube videos, etc. I submit that ED has pretty much nailed it. Here is a completely slick Hornet with 60% internal gas, at near-sea level, through a few max G turns...But keep in mind, I've flown these WITHOUT the paddle switch employed, as a real USN Hornet would be (and which would be reflected in real world EM performance charts) flown, real world. This is obviously only one, non-extensive, test, but you get the picture. The paddle makes a fairly significant difference.

Max sustained turn rate in this test was 18.5 Deg per sec. These were all max stick deflection pulls, in full AB. You can definitely get the little chart at bottom left to read higher in the 23-24 deg per sec range, but if you actually watch the live "object box", those dps are not sustained but momentary, and at low airspeeds... which makes the chart itself a bit misleading. Truly sustained, after testing both the Viper and the Hornet, the Viper has a consistent 1.5-2 deg per sec. sustained advantage when watching the live object box in TacView.

STR - Slick Hornet - SeaLvL.trk 110.71 kB · 3 downloads Tacview-20240402-215526-DCS-STR - Slick Hornet - SeaLvL.zip.acmi 25.24 kB · 3 downloads

 

 

It is obvious, that you lack basic understanding of the subject you are trying to post about.

Please, at least try to educate yourself about basic concepts, like what maximum sustained rate is, before trying to correct others...

 

 

[Cab]

59 minutes ago, HWasp said:

 

It is obvious, that you lack basic understanding of the subject you are trying to post about.

Please, at least try to educate yourself about basic concepts, like what maximum sustained rate is, before trying to correct others...

 

 

It would be useful for the discussion to hear what you think the OP gets wrong.

[HWasp]

59 minutes ago, Cab said:

It would be useful for the discussion to hear what you think the OP gets wrong.

Just to keep it short and simple:

Maximum sustained rate occurs in this case, where the 7.5G limit (in this config) can be first maintained without losing speed at constant max.AB. That speed will be around 400 or less for the given weight. OP is flying much faster than that, resulting in lower rates than the maximum available (even 490 in the second turn). OP is also obviously not keeping constant max AB, as that would result in acceleration at those speeds and Gs.

What you see on the tacview are 2 random turns at different speeds (not even held constant..,), neither of which are anywhere close to the actual maximum performance of the aircraft.

[Cab]

Thanks

[Razor18]

Just like Wasp said it.

Also refer to as "corner speed". It is somewhere around 360-380-ish kts for the Hornet depending on weight and altitude. And you only pull the stick so much as to "sustain" this speed, nowhere near "max stick deflection", because max deflection is only to see the instantenious turn rate, but you can not SUSTAIN it.

When at corner speed, if you see your speed going up, pull the stick a bit more, if you start slow down below that, release the stick a bit until speed catches back up. THis way you can have max turn rate "all day long" (until running out of gas of course realistically). Anywhere faster, and your turn rate will be lower because of G limit, anywhere slower and you will not be able to pull and SUSTAIN max G.

Edited April 3, 2024 by Razor18

[Theodore42]

I'm not sure OPs methodology is sound but

I've noticed the EM charts for jets with afterburners seem to indicate the max sustained turn rate is at or near the G limit, not the corner speed.

[HWasp]

4 hours ago, Theodore42 said:

I'm not sure OPs methodology is sound but

I've noticed the EM charts for jets with afterburners seem to indicate the max sustained turn rate is at or near the G limit, not the corner speed.

Well, both are at the G limit in this case. Corner speed is the minimum speed, at which the aircraft can pull the maximum G available (regardless of speed loss). In this case, the lowest speed, where 7.5G is available. This will also produce the max ITR.

Max STR will come at a higher speed, where the Ps0 line meets the 7.5G limit.

OP flew much faster than either of these speeds for the given weight, so it's all invalid.

[HWasp]

14 hours ago, Theodore42 said:

I'm not sure OPs methodology is sound but

 

 

I've finally got to replay the track in DCS, and this is much worse, than I thought. OP has set the temperature to 41 degrees Celsius in the "test" to get the wanted results.... 

So it turns out this is not a case of simple incompetence and lack of knowledge, but an actual attempt at disinformation (a really bad one though )

 

Not sure if this should be just laughed at or reported to the mods. I would think, spreading misinformation on purpose here just to bait people is a bit too much. 

[HWasp]

Just to make it clear for those people, who are not familiar with this:

Outside air temperature has a very large effect on jet performance. Usually a standard temperature of 15 degrees Celsius is used for tests and diagrams. DCS default is 20 C.

Higher temperature leads to decreased performance.

[Kefa]

Where is the documentation that specifically states that opening g limits past 7.5g, i.e. using the 'paddle' will increase maximum sustained turn rate?  I am willing to bet that the real life Hornet natops em diagrams that nobody seems to have, including ED, only tested the jet up to 7.5g.   

For example, the F-14A natops has em diagrams at about 6.5g and also out to 7.5g., and all that shows is that P's (including Ps=0 line) are still on the decrease regardless of the expanded g limits.  It is just my opinion, but I do not think that the paddle equates to a 'turbo' button on the jet at least for sustained turn rates.  If anything the paddle will give you expanded instantaneous turn rate.  Meaning that typical Hornet corner velocity of 7.5g at 310knots will now allow the pilot to pull to 9g with a bit more speed;  all while at the cost of  higher energy bleed rates.   

Edited April 6, 2024 by Kefa

[Cab]

15 hours ago, Kefa said:

Where is the documentation that specifically states that opening g limits past 7.5g, i.e. using the 'paddle' will increase maximum sustained turn rate?  

I don’t think there is any real world documentation for that. But it does seem to be the way the jet behaves in DCS.

[RoddersAndDodders]

I haven't done it in ages, but you can get 20-21-ish sustained as per the figures that were released in a GAO document (it was bashing the Super Hornet a bit so it was picking the points where the classic Hornet had an edge) pretty much bang on. The issues is that it's just a single datapoint, and the Hornet is on a bit of a knife edge doing it - if you get slow you really get slow fast, and if you get fast the G limiter starts limiting your turn rate. Pulling the override just make it a little more F-16 like where it can do good STR over a greater range of speeds but this is IMO abused by people who then complain it over-performs. I typically do it at 360-400KIAS depending on weight but if you're fighting someone it's much more fluid than hitting numbers like that.

IIRC - The big advantage of the F-16 is the rate speed is high over a portion of the envelope and because it can use vertical and gain speed so fast, it can force the hornet to get slow by being able to sacrifice some speed to get the nose around while not losing out much on the ITR.

Also, any time you're >15,000ft the Hornet starts to lag behind pretty much everything. I personally think ED did a good job for public only data sources.

[wilbur81]

On 4/7/2024 at 9:12 AM, RoddersAndDodders said:

I haven't done it in ages, but you can get 20-21-ish sustained as per the figures that were released in a GAO document (it was bashing the Super Hornet a bit so it was picking the points where the classic Hornet had an edge) pretty much bang on. The issues is that it's just a single datapoint, and the Hornet is on a bit of a knife edge doing it - if you get slow you really get slow fast, and if you get fast the G limiter starts limiting your turn rate. Pulling the override just make it a little more F-16 like where it can do good STR over a greater range of speeds but this is IMO abused by people who then complain it over-performs. I typically do it at 360-400KIAS depending on weight but if you're fighting someone it's much more fluid than hitting numbers like that.

IIRC - The big advantage of the F-16 is the rate speed is high over a portion of the envelope and because it can use vertical and gain speed so fast, it can force the hornet to get slow by being able to sacrifice some speed to get the nose around while not losing out much on the ITR.

Also, any time you're >15,000ft the Hornet starts to lag behind pretty much everything. I personally think ED did a good job for public only data sources.

Indeed. 

Here's a nice little break turn video of a small-motored Canadian CF-18 in 1988 doing 360 degrees in about 16 seconds... averaging a nice little 22 degrees per second, and with energy to spare. 

 

Edited April 17, 2024 by wilbur81