myHelljumper

This is an error. I just checked and to reset the designation you have to cycle weapon system command aft then fwd.

Hi, I'll have to check but IIRC no, in order to un-designate in CCPL you have to return to pre-selected or memorized mode using weapon system command aft. You also can designate as much as you want so there isn't really a need to un-designate.

Yes, I'll share the stick deflection to commanded G graph when I get home, but it's not a straight line.

Hi, No, no need to add curves as the ratio between stick deflection and commanded G load is already non-linear. And yeah, basically the more G you want the more force. The forces are fully artificial as there is no link between the stick and elevons, is it generated by a spring box.

That's the forces, it's from the future update to the manual :).

Hi, No, the training missions are not up to date. I'm working on improving/updating them but it takes a lot of time. You can use the manual in the mean time, almost everything there is up to date. You can also use Chuck's guide for a more compact format. Thanks.

Yeah, we are splitting hair here. While we want to be open about our model and try to demonstrate its accuracy where possible, I feel like this is going to be an endless debate.

Because the aircraft can do 14 nm per 10 000 ft at 280 kt as described ? Since the procedure falls short only if we drop the gear, I conclude that the landing gear might have too much drag.

Yeah as I said before I forgot to write that, my mistake. That's how the procedure is described, I think that's because that gear will take 20 seconds to lock and you need some time to notice it didn't work and to use the emergency gear handle. Also, 230 kt is a minimum speed (I guess I forgot to add that too), you should slow down at least to under 270 kt at it is the maximum speed for the gears. 230 kt should be the speed just before the flare. I'm also barely able to make it work when doing the final at 230 kt, maybe the gear induced drag is a bit too much.

Sorry I should've been more precise, the procedure scenario starts at 30 000ft and gives 41 nm. Also the gear should be dropped at 5000 ft when the speed is 230 kt. So the whole proc is : 280 kt indicated should give you 41 nm from 30 000 ft (~14 nm per 10 000 ft). 280 is chosen because it's close to the best glide speed (~260 kt) and inside the engine relight domain. The slats should be forced in. Stabilize at 5000 ft to slow down to 230 kt minimum then drop the gear. Maintain 230 kt in final.

From my dead engine tests with 100% fuel I have 39 nm until touching the ground following the procedure speed. Using 200 kt I have 35 nm Using 260 kt I have 42 nm. Looks like it work as expected to me.

And you are ignoring all the other facts that indicates that this is a 2000B with a M53-5. The 5% per 15°C is true for the M53-P2, I don't know about the M53-5.

So you are now choosing to ignore direct pilot feedback that indicates that this is not a 2000C but rather a 2000B with a M53-5 engine to make the video align with your views ? Rather than concluding that we cannot use this video as a source for STR ?

As I said we are sure that the airbrakes efficiency is correct, then the only other variable is the aircraft drag with AoA. The Jx being similar does not mean anything temperature wise as we don't know the reference Jx for a M53-5 engine. Every data point for the 2000C with M53-P2 engine that I've shared is working with our model, and the only thing you choose to use as a reference an aircraft with another engine. It only means that the module should be capable of at least 4.8 g at 400 and 340 kt. We can't share more than what we did already so you guys will have to use this information to make your opinion.

No, thrust is not static and changes with speed and altitude. We know the M53-P2 thrust profile from publicly available information, we don't know about the M53-5 thrust profile.

Using the B version video is not pertinent as we have even less information on the engine performance. But we can agree to disagree here. I only used the crash video to demonstrate that there is drastic increase in drag with AoA but I agree that it's not that useful. If you want to talk about the 5-12° AoA range, we can use the break procedure as a reference as the initial turn is mostly done in that range: The initial turn should be started at 1500 ft AGL, 350 kt. Angle of bank should be 60°, engine at idle and airbrakes out. The turn should be maintained until 200 kt then the AoB should be reduced to 40-45°. Since this turn uses the airbrakes, its accuracy is dependent on the airbrakes effect being accurate, but IIRC we used a good reference for their efficiency. You will see that when close to the maximum landing weight, the above procedure can be followed with around a 40° turn left to the down wind at 200 kt. That's inline with the info that we have.

It's relevant that the Mirage does not suffer from a critical increase in drag from high AoA as the engine thrust was reduced enough to decelerate but the higher AoA did not increase the speed loss rate further. I know it's not hard data but in the previous FM where the STR was lower than it was now, holding above 14° AoA back then with a healthy engine was already not really a confortable situation so the reduced drag at high AoA and thus increased STR makes sense here. Hydraulics is on our todo list for improvements. The procedure being doable at lower speed is not a sign of an issue, you should just get less glide range as it not the best glide speed.

230 kt is chosen because it keeps the engine rotating at at least 10%, which gives enough hydraulic power for the control surfaces. I should add to the dead engine landing procedure that you should at 230 kt from 5000 ft you should be able to fly 4 nm to the runway. Why would we change the FM to make it match with a data point that we know is incorrect (wrong airframe and engine) ? The Mirage can really take some AoA without much drag increase thanks to the unstable design that reduces the elevon drag at AoA, the slats (not relevant in the dead engine landing case) and the strakes. This this video where a 2000D with a malfunctioning engine keeps flying way past 14° AoA:

Unfortunately, as no public data exists, we cannot fully demonstrate that our model is realistic. This is the limitation when working on these kind of aircraft, but people have to put a little bit of faith on the dev teams otherwise a lot of aircraft would not be doable.

It's a straight in approach, you should be at less than 30° from runway heading when stabilizing at 5000 ft and should not have more than 45° roll angle.

So the procedure goes as follows: 280 kt indicated should give you 14 nm for 10 000 ft. 280 is chosen because it's close to the best glide speed (~260 kt) and inside the engine relight domain. The slats should be forced in. Stabilize at 5000 ft to slow down to 230 kt minimum. Maintain 230 kt in final. This procedure does not give fuel or configuration information but we can guess that in such emergency external stores would be jettisoned so the procedure must be possible with basically full fuel and no stores. I'll record a track later.

We can talk about the dead engine landing procedure if you want, this one was used to tune the aircraft drag and lift.

@HWaspI wasn't aware that the aircraft was a twin-seat with a M53-5 engine, this makes this comparison not very pertinent except for rough estimate of where the STR should be as 10% trust can change it a lot. Thank you again for the detailed analysis of the other parts of the video that showed a difference with our model. I just want to clarify that this particular video was not used as a data-point to tune the Mirage FM, as said before the turns are not perfect sustained turns and are there are too few of them to build a coherent model. I just watched it again recently and spotted some near sustain turns that we could use to have an idea of the accuracy of the Mirage FM.

The training missions are outdated for not but I'm working on it. The module manual and Chuck's guide are you best friends.

I find it unlikely that the aircraft would start from anything else than 100 on the pad as per SOP. After that as JoJo said 200 kg is coherent. Unfortunately we can't know for sure unless we ask the pilot from the video. I'll test 30 °C turn performance a little bit later. Edit: I personally find it more likely that the aircraft started at 100% fuel as its the SOP and a lots of performances checks assumes this fuel state for the aircraft. But you are free to disagree :).