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-   -   British FM killing the fun of the game for allied pilots. (http://forum.fulqrumpublishing.com/showthread.php?t=33942)

SlipBall 08-24-2012 09:05 AM

Back a few months ago, when the devs bowed to community pressure on the bouncing rpm needle. It was then that I realized we would most likely have Fm's of popularity, rather then true to life representations. :)

Robo. 08-24-2012 09:13 AM

Quote:

Originally Posted by JG52Krupi (Post 456331)
I have flown the spit a few times these past few days and it certainly is a very stable aircraft it's a joy to fly compared to the 109

Well Krupi, I have to say I personally don't share your opinion all that much. I always feel like I used to borrow dad's 'proper' car when I switch to the 109 regarding the handling etc. Stability is certainly not the strongest point of the Spitfire for her nose dances all around the place (compared to the Hurricane or 109) and she's very difficult to to control and aim, especially at slower speeds and / or in the climb. For me personally it's the matter of rudder response I guess. It's not so bad in mid to high speeds. Also, the stability of 109 got slightly worse in recent beta patches, or so it seems to me. Maybe it's also about flying style etc...

Lack of ammo is mater of what you're used to I suppose, when you adapt it's plenty. I agree it's very tough sometimes, that concerns mainly wings DM from visual point of view. You will find that if hit hard, this is no longer a fighter aircraft, like everything else in game. For flak damage, you also get lots of 'control lost' situations. The holes in the wing are not matching the actual FM imho, that's more of a visual bug. Just like Hurricane or 109 fuel tank explosion - funnily enough you almost never blow up the Spitfire, something is wrong in there!

Your summary is spot on of course, don't get me wrong, just correcting the stability issues for slower speeds, I find Spitfire much harder work in that kind of fight. Try the Hurricane if you care, that IS a very stable gun platform.

NZtyphoon 08-24-2012 09:25 AM

Quote:

Originally Posted by klem (Post 456312)
Crumpp the whole point of my producing that test mission for you was so that YOU could prove your point. My test was only a quick and dirty. Why aren't YOU taking the trouble to do some of the work yourself?

Just for interest here is what the NACA engineer (William Hewitt Phillips)
who compiled the report on the Spitfire VA
http://i91.photobucket.com/albums/k3...s-page-001.jpg

later wrote about the stability of many of the fighters tested, including the Spitfire:

http://i91.photobucket.com/albums/k3...-page-001a.jpg
Quote:

The Spitfire had desirably light elevator control forces in maneuvers and near neutral longitudinal stability. Its greatest deficiency from the combat standpoint was heavy aileron forces and sluggish roll response at high speeds.
Quote:

...these modes did not concern the pilot because his normal control reactions prevented the modes to a point where they were noticeable. That is the planes were spirally unstable but the rate of divergence was small enough that it was not discernible to the pilots.
(from NACA Monographs in Aerospace History Number 12)

If Crumpp wants to continue with his time wasting obsession over the Spitfire's elevators that's fine - it gives him something to do. There are more important issues to deal with, mainly the shortfalls in relative performance.

Incidentally the NACA report on the control characteristics of the Hurricane is available here

JG52Krupi 08-24-2012 09:53 AM

Tbh i have yet to fly the 109 in the latest beta patch but certainly in the previous beta patch the 109 was a terrible gun platform and from my experiance the spit is the better of the two so i will try the 109 tonight, I agree with you about the hurri its the best gun platform.

winny 08-24-2012 10:04 AM

I also found this, it's an explaination of the requirements set by NACA when testing. It explains why they tested for instability, what they were looking for etc.

Written by Robert R. Gilruth 1941 Requirements for Satisfactory Flying Qualities of an Airplane

http://aerade.cranfield.ac.uk/ara/19...report-755.pdf

Ze-Jamz 08-24-2012 10:24 AM

Quote:

Originally Posted by ATAG_Dutch (Post 456259)
You think?

To me it sounds like the same old protagonists/antagonists pissing on a wall.

Exactly

Ze-Jamz 08-24-2012 10:25 AM

Quote:

Originally Posted by Robo. (Post 456263)
On the same old wall :grin:

..still going, it will never stop though..took 7 years in il2

ATAG_Bliss 08-24-2012 10:27 AM

Just wanted to post about the oil pressure / engine damage thing:

A standard engine isn't going to be hurt from decel with momentary loss of oil pressure. What I mean by decel is, the engine went from having fuel and cylinders firing to running out of fuel and engine taking a few seconds to come to a stop. A thin layer of oil is around the main/rod bearings to absorb the punishment of the piston going into its compression stroke only to be exploded the opposite direction with combustion. This is violent on the bottom end as all the preload for the rod bearings and that particular connecting rod go from the bottom side of bearing(s) to, when combustion happens, to the top 1/2 of the connecting rod bearing(s) ( all in a split second). Without combustion, freewheel, all you have is the compression stroke causing stress which is absolutely nothing in comparisone to the grenade in the hole slamming the piston down that is called combustion. The biggest chance for airated oil to cause damage is when you regain fuel and the motor kicks back in again, but even then you would have had to fly in such a way that when you ran out of fuel and the engine is on decel to a stop, that you had enough neg g's or were inverted enough that oil never came back into the sump in the 1st place before you fired back up. Kinda like firing up your car after an oil change. Either way, I think if this was to be modeled it would be such a rare occurance that it wouldn't even be worth doing. Basically putting this in the bug tracker isn't correct IMO.

NZtyphoon 08-24-2012 10:46 AM

Quote:

Originally Posted by ATAG_Bliss (Post 456365)
Just wanted to post about the oil pressure / engine damage thing:

A standard engine isn't going to be hurt from decel with momentary loss of oil pressure. What I mean by decel is, the engine went from having fuel and cylinders firing to running out of fuel and engine taking a few seconds to come to a stop. A thin layer of oil is around the main/rod bearings to absorb the punishment of the piston going into its compression stroke only to be exploded the opposite direction with combustion. This is violent on the bottom end as all the preload for the rod bearings and that particular connecting rod go from the bottom side of bearing(s) to, when combustion happens, to the top 1/2 of the connecting rod bearing(s) ( all in a split second). Without combustion, freewheel, all you have is the compression stroke causing stress which is absolutely nothing in comparisone to the grenade in the hole slamming the piston down that is called combustion. The biggest chance for airated oil to cause damage is when you regain fuel and the motor kicks back in again, but even then you would have had to fly in such a way that when you ran out of fuel and the engine is on decel to a stop, that you had enough neg g's or were inverted enough that oil never came back into the sump in the 1st place before you fired back up. Kinda like firing up your car after an oil change. Either way, I think if this was to be modeled it would be such a rare occurance that it wouldn't even be worth doing. Basically putting this in the bug tracker isn't correct IMO.

+1

Without any proper data as to when and how damage will occur nothing much will be accomplished by attempting to replicate such a condition.

ATAG_Bliss 08-24-2012 10:47 AM

Quote:

Originally Posted by NZtyphoon (Post 456270)
I'm sure it happens - what is needed is some empirical data to show how long it takes for the oil pressure to drop below the minimum safe level. How much negative g is needed to lower the oil pressure enough to cause damage? The Pilot's Notes General, for example, describes one condition imposing too much negative g is a succession of slow rolls - so how many pilots are going to indulge in successive slow rolls during combat? What other combat conditions will impose enough negative g for long enough to damage the engine?

The normal oil pressure for the Merlin is 60lbs/sq.in, with a working minimum of 30lbs/sq.in. For gameplay a rough rule of thumb could be anything below 30lbs and the engine begins to suffer progressive wear (according to the Pilot's Notes General it doesn't take long for damage to occur once the oil pressure drops below the minimum).

The typical rule of thumb for any combustion engine is you need at least 10lbs of oil pressure for every 1000 RPMs. That is bare minimum. The volume/flow of oil needed is different for every engine. One of the reasons to have a good volume of oil / high volume oil pump is the hopes that during normal startup, by the time combustion happens you have already lubricated the bottom end before engine start (during the cranking process). If the pump only put out 10lbs per 1000 RPMs, the engine could be oil starved every time you fire it up. The real key is having high volume when you need it and be able to slave off excess oil pressure via a bypass valve when you don't. Too much oil pressure can also wash the bearings and cause failure as well.


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