Low level max speed and power....too low
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Being a massive fan of all the V-bombers, I've read a fair number of books, real flight manuals and other materials on the Vulcan. It's clear that although 240-300kts was a common low level speed in training, in wartime attacks would be carried out at circa 360kts, with once only dash speed of 415kts!
The max speed we can achieve in the JF Vulcan is about 340kts, flat out. This seems too low and is at odds with the real data out there. Clearly Vulcans were not routinely flying around at 415kts, this would have been a wartime 'Outrun this MIG-21' or 'Escape the WE177 blast radius' speed. But...I would expect to reach circa 360-370kts with ease.
Is there a reason why the JF Vulcan doesn't have this Low Level performance?
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Having spent a few hours tearing around Lincolnshire at low level, I have been able to reach 415 kts. 97% fuel, no payload so AUW in the high 170,000s.
The really bad news is that to do so was not 'easy' and the primary drag figure had to be heavily adjusted:
"In the modern flight model, this defines the target that will be distributed over all the surfaces of the aircraft when building the airplane used in the aerodynamic surface simulation. Once the aircraft is built, it will then be normalized to match exactly the target ." (MSFS SDK).
what I had to do was reduce Cd0 from a realistic 0.0242370 to a 'might as well not be there' 0.00512370. Five times less drag than the realistic figure for an increase in speed of roughly 60kts. That is bound to have repercussions elsewhere.
There is no doubt that in order to get the Vulcan flying anything like a Vulcan I have had to be 'creative' - I have a feeling the core game flight model's normalisation process is screwing up the drag because it is really not intended to calculate something which is not GA or an airliner, and whilst most other aircraft may get away with it the Vulcan is just so far from anything else that the game does what it thinks is right and is actually very wrong.
I'll keep looking at it and see if I can achieve something more comfortably realistic but without throwing anything else off.
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Wow Ok, that’s sounds bad news on the surface. Is this purely an issue with the performance at the extremes of performance? Can we assume the drag performance is correct at the rest of the speed range?
I don’t think anyone would want an artificially boosted flight model across the board, just to reach a very rare 415kts. Ultimately I can live with lower top speeds if the rest of the flight model is accurate and on point……
Thanks for looking into it.
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@Adam106 said in Low level max speed and power....too low:
Can we assume the drag performance is correct at the rest of the speed range?
The entire flight model is a compromise because MSFS does not deal well with a thick delta wing. This is where the problem with normalisation comes about - the game's core flight model cannot deal with the actual shape of the aircraft. I have grown up with Vulcans, so this for me was one I wanted to get absolutely right and (for example) the fact that the mach tuck starts at 0.94M instead of 0.88M and I can find no way to adjust that without compromising the rest of the flight model is a massive frustration! In terms of the specific of your question, the drag, well the actual figure is accurate but how the 'normalisation' works and affects the overal performance is down to Asobo. Figures and performance in the normal flight envelope seem to be on the mark. Induced drag has had to be massively increased because (again) the game cannot deal with a large triangular shape being pitched up to create drag. It means you can use aerodynamic braking on the landing run, unfortunately it also means you will bleed airspeed slightly too quickly if attempting toss-bombing unless you are very careful. I'm hoping that the promise of returning full flight model control to developers in the next version of the game will give me the chance to correct the various areas which I am not happy with.
Having said that, my research has included conversations with several Vulcan pilots and one at least will be flying this in the near future and whatever feedback comes my way will be worked into it as best I can. Climb performance, mach numbers, endurance and (most importantly) handling across the altitude range should actually be closer than our previous versions (P3D and X-Plane) because we are fairly well tuned-in to where it should be but we'll see what the above feedback gives and work on from there.
You mention manuals . . .
image url)And that's without the books! Just today, I was deep in the servicing manuals because of a slight issue noted with the nosewheel. I set the correct figures based on the actual measurements of the airframe, the game didn't like. So I worked it backwards and have reached a point where the problem is no longer an issue.
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