Thanks, I’ll have to experiment with it some more (I travel a lot for work and can only really mess with MSFS on the weekends), though it would be nice if the plane had a basic altitude hold/heading hold autopilot function. Unfortunately, I’m not sure at all how the Darkstar’s flight characteristics are modeled vs. altitude (and the related air density, etc.), as on the most recent flight I had with it I just sort of let the plane do it’s thing while accelerating to try to avoid disrupting the process, and it easily reached about Mach 9.75 while passing 200,000 ft MSL. I think it stayed at around that altitude and Mach 9.5+ for somewhere between 5 to 10 minutes before it abruptly decided to go back down to about the Mach 6 that I previously mentioned.
IT WORKS. I finally did it and landed at Cape Canaveral. Mach 9+ following ‘Objectives’ inset.
I have exactly this issue: I make it to mach 9.5 easily, and can maintain it for a while, then suddenly, without any significant change in control input (just maintaining straight and level as much as possible around FL 1200), then suddenly the zoom changes (to simulate a sudden drop in power) and the speed rapidly drops to about 5.6, as you say. I’m doing more flights to try to spot what might be changing on the scram parameters. Please let me know if you figure out why this is happening!
I haven’t figured it out yet, but I have some suspicion that it may be due to some kind of control binding conflict. I don’t really fly the Darkstar enough to want to risk potentially messing up something else by doing a “reset to defaults” on the controls yet, at least without doing some sort of backup of or documenting the current configuration.
So far on the Darkstar flights I’ve done, I get maybe a third of the way through the flight at mach 9+ and then do the rest of the way at maybe mach 6.5-ish. (I’m like, hey, at least it’s more than 6 times faster than sitting in an airliner doing this…) For some reason, I feel like the deceleration often happens right after one of the times I have gone to external view and looked around for a bit with the mouse right click and hold, but that may be just a correlation and likely not a consistent one at that, as I will have done that several times in the flight before the deceleration occurs.
One tip is that, while I don’t know if this would be realistic, the cruise speed after the deceleration appears to be faster if your altitude is higher, e.g. if I let it climb to around FL2000 I can get more like mach 6.5-6.7, so at least that should let you get there a bit faster while we figure out what the issue is.
I just succeeded at getting all the way to Cape Canaveral at mach 9.2. The only thing I did differently was to use trim to try to maintain FL 1200, instead of using the yoke. No idea if that made a difference. I’m wondering if it has to do with temperature requirements for the scram jet. I was watching the temps and they varied a bit, but I want to see the temps when it seems to shut down and drop to mach 5.
It was a one off success for me. It still keeps happening every time. Still no idea why.
I finally figured out the problem with the sudden loss of speed from mach 9 to mach 5. The after burner was flaming out! I don’t know if I was hitting the button (I don’t think so), or what it hast to do with the scramjet, but all you have to do when it happens is hit the after burner switch and will soon be back to mach 9+. smh
Sounds good, I’ll try that the next time it happens. I know I definitely wasn’t touching the throttle at all the times this has happened, but it might be something where there’s a bit of jitter in the signal (like you sometimes see when looking at a device in Game Controllers → Properties or when adjusting curves with some input devices) and the system sees 100% → 99% momentarily or such and thinks you’re pulling the throttle back.
It was actually running out of fuel for the turbines (normal engines). I’m confused about the continued turbine fuel consumption during scramjet operation. I thought the turbines should automatically switch off. Most of the write-ups talk about firing up the turbines during the descent. So, I don’t understand the use of after burners to keep the scramjet at full power.
Regular engines should be off. Scramjet is enough to keep you at Mach 10 easily.
Press the fuel cell switch and then the scramjet switch. The latter is under a red cover (click the cover to open it)
First time Solo on Darkstar from Frankfurt to KSEA without guidance.
I switched on the Sramjets at Mach 2.8 (alarms) and they immediately kicked in at M3 and shutdown Eng 1&2.
Can’t get to Mach 10 though, I was only able to get to Mach 9.81.
300nm from KSEA, I shut down Scram Jets at FL80k, glided to FL50k, then restarted Jet Engines, Landed safely no issues, thanks to lot of zero visibility practice & lessons from fsacademy.
Looking forward to doing it again to achieve Mach 10
Yep you can exceed Mach 10 on this thing. The climb has to be just right
Fastest I’ve hit is mach 10.07
Look into the missions and technique threads im building. Its a work in progress as I have to fly each route or technique multiple times to make it more standard and tighter constraints. But Id love to get a Darkstar community going.
Theres a lot to unpack in this thread. Im going to upload videos in a threat “Darkstar: why youre flying it all wrong” to demonstrate that the aircraft is immensely more complex than people realize.
I attribute this to the fact it does the mission easily enough.
As long as your flight is like the mission then the Darkstar is easy.
But the mission only explains half the systems and none of what they do. I believe they lifted the flight model and systems from SR71 or concord.
Example, the plane’s stability is terrible. The control surfaces are not enough to manage the plane’s CG. This is true with the SR71 and the SR71 had to manage its fuel tanks to rebalance the CG.
At take off you run your engines at 90% and you use all fuel pumps. But as soon as you have taken off you begin your climb. When the nose naturally pitches to about 30deg you will lose acceleration.
Then you go to 100%. Then when that speed tapers off you go to afterburner and turn OFF the aft fuel pump.
This means youve used some of the weight in the aft but the fuel pump being shutdown prioritzes the side pumps.
Probably unintentional to programming you can not force the front tank to be the only one used.
This arrangement makes the Darkstar MUCH more responsive to controls.
Furthermore the Scramjet is temperature dependent. Not speed dependent as the mission implies.
The temperature of the scramjet is speed and altitude dependent. At 5,000+F it doesnt make much difference but when you configure for near idle long distance flights it makes a big difference.
Whats happening to you is youre probably running into these issues.
Thank @IDNeon for the tips.
I ran into several issues, you are totally right on the scramjet being temperature dependent, over a long flight, I reached Mach 3.5 without ever turning on the after burnera and they won’t come on, even at FL80k.
I played around with the Tanks and still can’t hit Mach 10. Every time I hit M9.85 it starts decreasing again. What’s the ideal altitude and speed to sustain Mach 10.
Should I continuously be diving to FL50k and climbing to FL120k to hit Mach 10+
You dont even need the Inverted Roll. Works also without it. For Land just use ILS.
Pretty easy, even from inside.
I have 4 engine control via Thrustmaster Airbus quadrant hardware.
The engine 3&4 throttle controls seem to work fine, but for some reason only engine 4 is lighting up, not engine 3. Anyone have any theories what might be wrong?