[NO CHANGE] Hornet FM tweak in 17/08 update?

[marcoacv]

Flying level at 40k feet no matter how hot, cold or freezing the hornet does not reach the 1.8mach disclosed. I tested without weapons and low on fuel. This loss of performance is notorious.

 

 

 

 

 

 

 

 

 

 

https://www.youtube.com/channel/UCKnltjOl7wUhhCxSaYJUW9Q?view_as=subscriber

Edited August 24, 2020 by marcoacv
My YT channel link

[Swift.]

Flying level at 40k feet no matter how hot, cold or freezing the hornet does not reach the 1.8mach disclosed. I tested without weapons and low on fuel. This loss of performance is notorious.

 

What makes you think you will get best speed at 40k?

[marcoacv]

What makes you think you will get best speed at 40k?

Performance

 

Maximum speed: 1,034 kn (1,190 mph, 1,915 km/h) at 40,000 ft (12,000 m)

Maximum speed: Mach 1.8

Cruise speed: 570 kn (660 mph, 1,060 km/h)

Range: 1,089 nmi (1,253 mi, 2,017 km)

Ferry range: 1,800 nmi (2,100 mi, 3,300 km)

Service ceiling: 50,000 ft (15,000 m)

Rate of climb: 50,000 ft/min (250 m/s)

Wing loading: 93 lb/sq ft (450 kg/m2)

Thrust/weight: 0.96 (1.13 with loaded weight at 50% internal fuel)

 

 

 

https://en.wikipedia.org/wiki/McDonnell_Douglas_F/A-18_Hornet#Specifications_(F/A-18C/D)

[Quid]

According to the -402 powered F/A-18C flight envelope, your top speed is going to be achieved at around 36,000-37,000 feet. I went ahead and tested it with a completely clean Hornet and it's just barely below the advertised 1.8M. The HUD held at 1.78M, while TACVIEW says 1.79M on the replay. This was on a 15 degree Celsius/29.92Hg day.

[Swift.]

Was just about to say, the things I'm looking at put the best speed for a -400 at about FL350-360. Don't know where to get a -402 performance charts manual, but I wouldn't take wikipedias numbers for anything.

[Quid]

Was just about to say, the things I'm looking at put the best speed for a -400 at about FL350-360. Don't know where to get a -402 performance charts manual, but I wouldn't take wikipedias numbers for anything.

 

GAO Report B-260367/NSIAD-96-98.

[DLEGION]

i'm more worried about F18 not being able to reach mach 1 with full amraam load… while F15 can reach mach 2.2 with 6 amraam and 2 aim9 (in DCS)

how is F18 supposed to intercept things ?

[Swift.]

i'm more worried about F18 not being able to reach mach 1 with full amraam load… while F15 can reach mach 2.2 with 6 amraam and 2 aim9 (in DCS)

how is F18 supposed to intercept things ?

 

Hornet definitely can reach >1.0 when laden, and supersonic speeds aren't required for an intercept. Interception isn't "catching up" to the bogie, its heading them off at the pass; use geometry, not brute force.

[Curly]

In dcs, she has kind of a itr plateau like the viper. Above ~20-22° Aoa she cuts the corner and is limited to ~28° Aoa between ~ m0.34 and ~m 0.42 at sea level (clean and with 2a9&2a120).

Same picture at 15kft, but here she achieves ~30° aoa at ‘corner’.

 

I think it should be more like 34° Aoa, that is at least what I have red...

 

 

 

 

Max AOA at CL max at 15k ft is 34 degrees.

https://ntrs.nasa.gov/citations/19950007836

The G limiter is what is preventing AOA greater than 34 degrees.

 

Corner is where CL max meets the airframe limitation. In this case the 7.5 g limiter.

 

CL max for the airframe is 1.8 at an AOA of 40.

 

To achieve that AOA you need to be below the G limiter.

 

https://www.nasa.gov/centers/dryden/pdf/88489main_H-2149.pdf

 

While There is no AOA limiter on the airframe. Pitch rate, NZ and AOA feedbacks will dampen pitch rates. It looks to that what you’re bumping into either the NZ limiter or aggressive integrator at action above 30 degrees of alpha.

 

https://apps.dtic.mil/sti/pdfs/ADA140143.pdf

[marcoacv]

i'm more worried about F18 not being able to reach mach 1 with full amraam load… while F15 can reach mach 2.2 with 6 amraam and 2 aim9 (in DCS)

how is F18 supposed to intercept things ?

Agreed.

Some people do not fly in multiplayer and unfortunately do not notice the changes that occur. I just came here to report that the plane lost performance and that is a fact.

[marcoacv]

Hornet definitely can reach >1.0 when laden, and supersonic speeds aren't required for an intercept. Interception isn't "catching up" to the bogie, its heading them off at the pass; use geometry, not brute force.

Try to intercept someone flying in multiplayer. You really believe that the F18 Hornet is that weak!

[VIXEN413]

hey all,

 

in my initial post I mentionned a few observations that lead me to do my own tests.

i based my observation on Natops, perfo manual (nfm-210) and some info of the GAO report

 

few observation that I did are in line with what others found too somewhat. So of course, the FM and drag is still a WIP so all this is to take with a pinch of salt and these are just observations. that's all

 

I took an f/a 18c loaded with 2 aim9 and 2 aim7, fueled to 60%.

the indicated weight in that config on the - 210 mention 33696lbs but dcs got us up to 33852 in that loadout.

close enough.

wing pylons has to be removed too for this. keeping them gave me some very weak result so. yes, they tax a lot of performance. each one of these SUU63 has a drag index of 7.5 in the perfo manual, centerline SUU62 also needs removal (DI of 3)

standard day at 29.92, 15degC wind calm.

 

1 Glim

I was wondering about the G limit given by the limiter. I compared some weight/Glim from the natops table to what we have in dcs and itvs almost bang on. so, all good there. only one small discripancy at 39000lbs that showed a limit at 6.3 instead of 6.5. (6.5 was attained whith weight under 38200.

great stuff.

 

2: max speed

the - 210 shows M0.95 at sea level and M1.02 at fl320 in MIL

 

DCS gave me 0.96 and 1.03 respectivelly so almost bang on! slight difference might come. from the difficulty to locate max MIL onnmy TQS without entering AB zone 1...

with AB, the plane goes to M 1.05 at SL and M 1.76 at fl360

here, I obtained some more slugish results with respectivelly M1.04 and 1.71

very close indeed but it seems that the drag wall is coming a bit too soon and the plane has a hard time to reach advertised speeds at optimum altitude.

 

3 acceleration

 

this gave a bit more answers.

we have - 210 infos and also some in the GAO report.

the GAO is very optimistic and one has to keep in mind that those numbers might be changed for better numbers to seduce congressmen... but ok, let's see them too.

GAO mention aim 120 witch has a slightelly better drag performance on the natops manual but after teying it out, it did not made a difference in DCS actually.

 

all test are done with full AB of course.

 

at 10000ft

from M0.8 till M1.08 takes 20s (21s in GAO) and DCS showed 22s

very close but the faster you wanna get, the bigger the Delta time with real performances.

from M0.8 to M1.15 takes 29s but in DCS an average of 38s

from M0.42 to M1.2 should be 60s but DCS gave us 92s

it is to be noted though that after 60s we reached M1.16 so the acceleration to M1.2 took 32 more sec just for 0.04....

 

data at 30000ft also shows quite a difference witch was weired.

 

data at 35000ft on the other hand were once more "bang on"

accelerate from M0. 8 till 1.2 takes 63s and DCS gave me 64s

awesome!

the GAO, like I said, might be optimistic as it gives us 56s....

M.8

did an accel from 0.8 to M1. 6 in 151s while - 210 gives us 145"

 

next up I ll play with turn capabilities too ;)

 

So we can see that ED did a pretty good job with the Flight caracteristics of the hornet in terms of speed and acceleration but somehow, the plane either hit the drag wall a bit too soon and ends up with slow acceleration on the high speed side of it's enveloppe or that it lack a bit of humpf in it's AB thrust.

 

nonetheless, I m impressed that the results are quite close. well done ED.

The thing to get right too now is also pylon and payload drag as those takes a big and notorious performance hit with the f18

 

best regards

[FightsOn]

hey all,

 

in my initial post I mentionned a few observations that lead me to do my own tests.

i based my observation on Natops, perfo manual (nfm-210) and some info of the GAO report

 

few observation that I did are in line with what others found too somewhat. So of course, the FM and drag is still a WIP so all this is to take with a pinch of salt and these are just observations. that's all

 

I took an f/a 18c loaded with 2 aim9 and 2 aim7, fueled to 60%.

the indicated weight in that config on the - 210 mention 33696lbs but dcs got us up to 33852 in that loadout.

close enough.

wing pylons has to be removed too for this. keeping them gave me some very weak result so. yes, they tax a lot of performance. each one of these SUU63 has a drag index of 7.5 in the perfo manual, centerline SUU62 also needs removal (DI of 3)

standard day at 29.92, 15degC wind calm.

 

1 Glim

I was wondering about the G limit given by the limiter. I compared some weight/Glim from the natops table to what we have in dcs and itvs almost bang on. so, all good there. only one small discripancy at 39000lbs that showed a limit at 6.3 instead of 6.5. (6.5 was attained whith weight under 38200.

great stuff.

 

2: max speed

the - 210 shows M0.95 at sea level and M1.02 at fl320 in MIL

 

DCS gave me 0.96 and 1.03 respectivelly so almost bang on! slight difference might come. from the difficulty to locate max MIL onnmy TQS without entering AB zone 1...

with AB, the plane goes to M 1.05 at SL and M 1.76 at fl360

here, I obtained some more slugish results with respectivelly M1.04 and 1.71

very close indeed but it seems that the drag wall is coming a bit too soon and the plane has a hard time to reach advertised speeds at optimum altitude.

 

3 acceleration

 

this gave a bit more answers.

we have - 210 infos and also some in the GAO report.

the GAO is very optimistic and one has to keep in mind that those numbers might be changed for better numbers to seduce congressmen... but ok, let's see them too.

GAO mention aim 120 witch has a slightelly better drag performance on the natops manual but after teying it out, it did not made a difference in DCS actually.

 

all test are done with full AB of course.

 

at 10000ft

from M0.8 till M1.08 takes 20s (21s in GAO) and DCS showed 22s

very close but the faster you wanna get, the bigger the Delta time with real performances.

from M0.8 to M1.15 takes 29s but in DCS an average of 38s

from M0.42 to M1.2 should be 60s but DCS gave us 92s

it is to be noted though that after 60s we reached M1.16 so the acceleration to M1.2 took 32 more sec just for 0.04....

 

data at 30000ft also shows quite a difference witch was weired.

 

data at 35000ft on the other hand were once more "bang on"

accelerate from M0. 8 till 1.2 takes 63s and DCS gave me 64s

awesome!

the GAO, like I said, might be optimistic as it gives us 56s....

M.8

did an accel from 0.8 to M1. 6 in 151s while - 210 gives us 145"

 

next up I ll play with turn capabilities too ;)

 

So we can see that ED did a pretty good job with the Flight caracteristics of the hornet in terms of speed and acceleration but somehow, the plane either hit the drag wall a bit too soon and ends up with slow acceleration on the high speed side of it's enveloppe or that it lack a bit of humpf in it's AB thrust.

 

nonetheless, I m impressed that the results are quite close. well done ED.

The thing to get right too now is also pylon and payload drag as those takes a big and notorious performance hit with the f18

 

best regards

 

Awesome stuff! That is good research. I think the major problem is not with power, but with AOA capability, and the insane amount of drag on the real jet when it's at such high AOA. Currently the Hornet in DCS has the correct power, but limited AOA/drag, so it seems like a rocket ship during maneuvering flight. If the devs can give us a better model of High AOA capabilities, and the associated drag rise, I think the jet would feel less 'overpowered' to us who've flown it.

 

Also...in DCS during BFM the jet is normally not saddled with all the crap we had to carry IRL. All the pylons, multiple external tanks, FLIR etc..

[RentedAndDented]

I don't know that it is that simple. The GAO document also gives a sustaiined turn rate that the DCS F/A-18 also closely matches (2 AIM-9, 2*AIM-120, 60% fuel).

It's had an adjustment some time ago with pylons, they now add a lot of drag and this would be the condition in which it is actually fought. In this case I think the F-16 will be winning but I haven't checked.