Sustained turn rate tested

[Hummingbird]

It's not like it's impossible, is it? AFAIK, there are certain conditions where the F-15 has a greater STR than the F-16, even though the F-16 outperforms the F-15 in STR in most other conditions. So it is possible that the same could apply here, right? It's obviously not as simple as x > y in all conditions.

 

I'm not going to sit here and say either FM's are perfect, and I never could say that, but I guess my point is it's possible that the conditions favor the F-15. Maybe it's realistic behavior, maybe it's not.

 

Only thing that could affect the comparison in such way would be if the Mirage & F15's engines differed enormously in performance at the height range of 0 to 15,000 ft, which just isn't the case.

 

As such if the Mirage is able to beat the F-15 in both STR & ITR from Mach 0.2 to 0.9 at 15,000 ft, then it will be the same at SL.

 

The exact same is the case if we pick the F-16, at 15,000 ft it features the same advantage over the F-15 that it does at sea level.

[Hummingbird]

Let's look at a few figures here:

 

 

Mirage 2000C

Fully fueled & loaded weight (clean): ~10,500 kg

T/W ratio: 0.95

Wing loading: 256 kg/sq.m

High lift devices: Full span camber increasing slats

 

F-15C Eagle

Fully fueled & loaded weight (clean): ~19,800 kg

T/W ratio: 1.07

Wing loading: 358 kg/sq.m

High lift devices: None

 

 

Subject of lift:

At first glace one can see that Mirage features a substantially lower wing loading than the F-15 (100+ kg/sq.m.), however this difference will obviously be reduced when also considering body generated lift, however the difference in wing loading is large enough that body lift will most likely not negate it. More crucially however is the fact that the Mirage features full span high lift LE devices whilst the F-15 features none at all, and this is a big deal as such devices usually increase lift by 50% or more.

 

Subject of thrust:

The F-15C enjoys a small advantage here, but being a bigger aircraft it also needs it as its therefore naturally also a lot more draggy than the Mirage - a crucial factor during sustained maneuvering.

 

In short: I don't see any chance that the F-15C would be anything but inferior in both STR & ITR at sea level to 15,000 ft and likely also higher. The F-15C might reverse the trend at higher altitudes if its engines are more efficient up there, but otherwise the disparity will stay the same.

Edited December 28, 2015 by Hummingbird

[RoflSeal]

To me it looks as though the STR of the F-15C at 15,000ft should be better then the Mirage. Take the approximate midpoint of the values of 10,000ft and 20,000ft you come out at a STR of 13.5-14.0 deg/s at M0.9 and and 12.0-12.5deg/s at M0.7 at 15,000ft. I don't know why the F-15C is being compared to in the first place anyway *shrugs*

Edited December 28, 2015 by RoflSeal

[NineLine]

We'll see.

 

Atm though the Mirage is performing at Sea Level as it should be performing at 15,000 ft.

 

Well I am not gonna try and stop you, but testing doesn't make a lot of sense on a version that's already outdated, just saying ;)

[Exorcet]

I can see the ITR argument, but the Mirage has the additional disadvantage of using pure delta wings for STR, which are going to be more draggy than the F-15's wings, slats or not. Would make a bigger difference than the fuselage contribution I think.

 

M2000 AR = 1.91

 

F-15 AR = 3.02

 

EDIT

 

The F-15 chart is 66% fuel, to the M2000's 50%, and the F-15 has a larger fuel fraction anyway, so it looks like the F-15 is vastly superior when it comes to sustained performance. The charts make them look close to even when the F-15 has a weight penalty. The two missiles on the M2000 would hurt it more than on the F-15 though.

Edited December 28, 2015 by Exorcet

[Hummingbird]

I can see the ITR argument, but the Mirage has the additional disadvantage of using pure delta wings for STR, which are going to be more draggy than the F-15's wings, slats or not. Would make a bigger difference than the fuselage contribution I think.

 

M2000 AR = 1.91

 

F-15 AR = 3.02

 

EDIT

 

The F-15 chart is 66% fuel, to the M2000's 50%, and the F-15 has a larger fuel fraction anyway, so it looks like the F-15 is vastly superior when it comes to sustained performance. The charts make them look close to even when the F-15 has a weight penalty. The two missiles on the M2000 would hurt it more than on the F-15 though.

 

Delta's don't suffer much in terms of induced drag in comparison to the F-15 which is a cropped delta wing design itself.

 

Also regarding drag there's a massive size disparity between these two aircraft, which will have a great effect on the total drag. The F-15 does after all need double the thrust to achieve the same speeds ;)

 

The two missiles on the Mirage are going to add quite a bit of drag as they are on pylons, thus you should see a´noticable difference in STR when the aircraft is clean.

 

Same is true for the F-16 once you start putting on wing pylons - fortunately it can carry two IR missiles on its wing tips however which have a neglible effect.

[Exorcet]

The wings are similar in a way, but AR difference is very large, ~150%. They are both low AR wings, but the different planforms should lead to different induced drag contributions and lift slopes.

 

The F-15 has higher absolute drag agreed, but it has higher thrust as well. The fact that they reach about the same speed suggestions that the thrust to drag ratio is proportional. The induced drag will be less of an issue in a top speed dash though. In any case, we have the charts. To me it looks like the F-15 doesn't have a significant disadvantage if there is one at all.

 

I agree on the missiles, the M2000 being small and having pylons in addition to the missiles will make their impact larger. The F-15 fuel load given in the chart details is no small amount though. Perhaps clean the M2000 would squeeze a clear advantage over the F-15, but this would be with a fuel % and fuel fraction advantage.

 

 

On a tangent, and a bit of a stretch at that, but is it coincidence that the M2000 and MiG-21 underperformed at launch? Could this be a core issue, at least partially?

[Hummingbird]

The wings are similar in a way, but AR difference is very large, ~150%. They are both low AR wings, but the different planforms should lead to different induced drag contributions and lift slopes.

 

We are down in an area where it won't matter much though, esp. when we factor in the lifting fuselage area.

 

The F-15 has higher absolute drag agreed, but it has higher thrust as well. The fact that they reach about the same speed suggestions that the thrust to drag ratio is proportional. The induced drag will be less of an issue in a top speed dash though. In any case, we have the charts. To me it looks like the F-15 doesn't have a significant disadvantage if there is one at all.

 

I agree on the missiles, the M2000 being small and having pylons in addition to the missiles will make their impact larger. The F-15 fuel load given in the chart details is no small amount though. Perhaps clean the M2000 would squeeze a clear advantage over the F-15, but this would be with a fuel % and fuel fraction advantage.

 

I'm also wondering why the ingame Mirage can't pull the high AoA maneuvers it should be capable of. The ingame F-15 loves being thrown into mini cobras, yet the same isn't possible in the ingame Mirage.

 

On a tangent, and a bit of a stretch at that, but is it coincidence that the M2000 and MiG-21 underperformed at launch? Could this be a core issue, at least partially?

 

Who knows, could just as well be the use of incorrect thrust, drag & lift figures.

[jojo]

In M-2000 you have full FBW which limit your AoA to 29 degree on low speed.

 

But this limit depends on speed, so at higher speed, lower maximum AoA...

 

I perfectly makes sense for FBW design.

[Corsair]

Don't expect max AoA above 250-ish knots. Such would cause overstress, drag peak that could lead to departure from controlled flight. As jojo said, FBW is here for that

[IvanK]

Here are the remaining relevant Mirage 2000 charts from the fighter symposium document. these are calculations from the Authors who were at the time subject matter experts though Northrop reps :

 

 

 

X marks the spot for a certain US fighter soon to be featured in DCS ... from exceptional source data :)

 

 

 

 

 

 

[Corsair]

Because they have strictly identical performance.

[jojo]

Because their flight behavior is very similar...

 

Same engine, same aerodynamic, same FBW.

 

French Mirage 2000-5F are upgraded former Mirage 2000 C.

[Hummingbird]

 

X marks the spot for a certain US fighter soon to be featured in DCS ... from exceptional source data :)

 

 

 

 

15 deg/sec at 15,000 ft? You've got my attention! :baby:

[tflash]

So, to sum up, the facts are:

 

1/ the source is not Dassault.

 

2/ the tables are for 15k, not SL.

 

3/ the charts are for Mirage 2000-5, not Mirage 2000-C.

 

I have no time for this, I'm going to fly the Mirage :=)

[Hummingbird]

So, to sum up, the facts are:

 

1/ the source is not Dassault.

 

2/ the tables are for 15k, not SL.

 

3/ the charts are for Mirage 2000-5, not Mirage 2000-C.

 

I have no time for this, I'm going to fly the Mirage :=)

 

The charts are for the same aircraft we have ingame, there is no aerodynamic difference, thus they apply 100%.

 

The table applies for 15,000 ft, yes, but that makes it rather easy to calculate the performance at SL.

[Elo001]

Because they had permission to print them in their manual. They can't just print anything in there from a legal perspective. This doesn't mean their flight model is purely based on the BMS charts. I'm sure they have used more sources for that.

 

http://forums.eagle.ru/showpost.php?p=2618052&postcount=2

[ineth]

An opinion....

 

It is nice to see the level of the Simmers in here but here is one simple fact. If you think you should fly the F15 because it sustains more g's do so.

Take the powerhorse easy way out and fly a wonderful plane and rule the skies.

 

What you fail to understand is that the M2000 was not designed with the F15 as an opponent in mind and even if the Soviet counterparts outperformed it too, if and in anyway, the M2000 was the labor of France and Dassault so that they stay unattached and dependent on foreign manufacturers for matters regarding their own national safety.

 

It is true that several other planes seem to have superior performance and weaponry (i would take an Excocet carrying M2000 over any Harpoon carrier on any given day though) but be warned. A dedicated hardcore M2000 pilot is going to perform a wonderful touchdown returning to base while the casual powerjokey on F15s or Su27s will keep trying to figure out how with sustained 9ers and flawless performance charts they ended up hanging on the underside of a chute.

 

ps

If Dassault never had made the M2000 we would not have the Rafale today, and that gentleman, is what it is. And it is Brilliant.

 

Fly safe.

 

Greek/German origin.

Flying sims since 1984.

Using computers since 1977.

Favored FS's:F/A18 Interceptor, F19 Stealth Fighter, Gunnship, F16 Combat Pilot, Flight of the Intruder, A320, Falcon 4.0, MSFS 2004-X, DCS

[GGTharos]

The F-15 happens to be a very familiar and exceedingly well documented benchmark when it comes to performance. It's used as a comparison point by a lot of us because there's a lot of available real information with respect to a bunch of its flight characteristics.

 

What you fail to understand is that the M2000 was not designed with the F15 as an opponent in mind

[NineLine]

Please try to keep data listed here either real world or from DCS World. The discussion of other sims, or material from those sims is not allowed here. This is a simulation of the real plane, not another sim or game.

[Hummingbird]

Cpt. Smiley,

 

Just curious, will the drag adjustment mentioned in the list of upcoming fixes solve the Mirage's lack of performance in STR and bring it back up to the values listed by Pawloski & Ball?

 

Based on Pawloski & Ball's estimates the Mirage should be capable of the following STR performance at SL w/ 2x IR missiles & 50% fuel:

 

4.0 G's @ Mach 0.4

6.7 G's @ Mach 0.6

8.3 G's @ Mach 0.7

9.0 G's @ Mach 0.75

 

 

I believe these figures by Ball & Pawlovski to infact be quite conservative considering that their F-16 estimates fall short by over 1 deg/sec & 0.2 G's in STR at 15,000 ft in comparison to the official performance of the heavier F-16C in an identical loadout condition.

Edited January 3, 2016 by Hummingbird

[IvanK]

The F16 in their report is the J79 powered F16

[Nealius]

The discussion of other sims, or material from those sims is not allowed here. This is a simulation of the real plane, not another sim or game.

 

The charts provided by Razbam are from a different sim. If you have that much of an issue with discussions of other sims then tell your third-party developers to not borrow/publish data from other sims. The community has no control over this.

Edited January 4, 2016 by Nealius

[Hummingbird]

The F16 in their report is the J79 powered F16

 

Not according to the chart which lists the F100-PW-220NSI being used for the estimates.

[IvanK]

Not according to the chart which lists the F100-PW-220NSI being used for the estimates.

 

We are talking about the Palowski report for the RMAF symposium arnt we ?

The one comparing Mir 2K, F20A and F1/J79.