Quote:
Originally Posted by cheesehawk
However, I'm a bit taken back by the above post, sounds to me like you're setting up a scenario that "Even if a vet says I'm wrong, I'm going to insist that I'm right?"
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That's a very over-simplistic attitude to take.
Firstly, people tend to have pretty imperfect memories. That's why we write things down. Very few people will remember precise details about aeroplanes that they flew 70 odd years ago.
I last flew a Bulldog about 10 years ago. I can remember the numbers which were most important to me; climb at 80 knots, loop entry at 140, stall turn entry at 120, VNE was about 200 knots, but you'd only get that going downhill very steeply (at which point, if you're 17 and will live forever, puling as hard as you can will get you about 6 g - "do what you want - it's going to the scrapyard tomorrow!").
I can remember that it used to be happier to stall turn one way than the other, but I couldn't honestly tell you which way was the easy way.
I couldn't tell you the engine limits off hand; there's a tendency to just remember that green is good and red is bad, so if it's green it's good and that's it. I know it'll handle negative g without complaint, because I did it.
The stall was well mannered, but I couldn't tell you the stall speed because I wasn't interested in stalling it; I wanted aerobatics. Anyway, there was plenty of buffet to warn you if you were close to the edge of the envelope.
I landed it quite a lot of times, but I can't even remember the speeds for that - 70 knots on approach? Probably a bit less over the fence and then you're not looking at the ASI anyway...
That's 10 years ago - ask me again in 60 and it'll be a wonder if I can remember what a Bulldog even was!
Secondly, it's not even as though you can just talk about "a Hurricane". Even in 1940 there were a heck of a lot of potential mod states knocking around.
The sim is seeking to model the performance of a couple of Hurricanes in defined mod states. Information relating to a different mark or mod state won't necessarily read across.
Of course, this observation equally reads across to current flight experience. Nobody operates Hurricane Mk I aeroplanes in their 1940 mod state anymore.
The average warbird knocking around has a civil Merlin (500 series for the single stage engines, 700 series IIRC for the two stage engines, though quite often you'll also see single stage engines retrofitted into aeroplanes that would originally have had two stage engines), or a transport command merlin (T.25) rather than an authentic fighter Merlin, because the latter offer considerably longer overhaul intervals. Most of the time they have FS gear disabled because they're only interested in low level work at airshows; hence the unfortunate tendency to retrofit single stage engines into aeroplanes which would originally have had two stage engines*.
It can actually be very difficult to work out exactly what engines and mod states current warbirds operate in, because the pilots often don't much care, the PR people haven't the slightest idea, and the engineers are generally too busy. In fairness, it's not the sort of question that they'll generally be asked...
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In other news, I have been experimenting with the Rotol Hurricane this evening using the latest patch, and it's
crazy. I get black smoke and misbehaviour at even slightly reduced positive (like 0.9ish g I guess; not much point getting out the stopwatch and calculating g from pitch rate and TAS; the rates would be too low for the results to be sensible). It's set off by turbulence, and you'd probably also get it from a gently phugoid (which would probably be the most repeatable way to test & quantify it; trim for say 200 mph IAS at 10,000 feet and then pull to x mph IAS slower than the trimmed speed and release the stick - naturally this this will generate a stick-fixed phugoid given the nature of the sim's modelling methodology - anyway, a given value of x should correspond to a fixed g load for the first cycle, and this is probably repeatable to smaller g increments than directly hand-flying a pushover).
The cut behaviour is obviously wrong, quite apart from the fact that it's on a hair trigger, because we're straight into rich cut with no preceding lean cut.
*Of course, a single stage engine will give more bhp at any given boost level because less power is consumed driving a single supercharger stage than driving two. Single stage engines are also lighter. So if you only want up to about +18 psi at low level then a single stage engine will deliver more performance, especially since single stage engines are obviously lighter, and the lack of an intercooler/aftercooler means that you've instantly gained a load of extra radiator if you're prepared to plumb the intercooler/aftercooler radiator into the main loop...