British FM killing the fun of the game for allied pilots.

[lane]

Originally Posted by NZtyphoon

Just for interest here is what the NACA engineer (William Hewitt Phillips)
who compiled the report on the Spitfire VA


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




(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

Nice post!

[Robo.]

Originally Posted by Crumpp

[B]It means the game shape is easier to precisely maneuver and get guns on a target than the real aircraft.

How do you know this?

[SlipBall]

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.

[ATAG_Bliss]

Originally Posted by NZtyphoon

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.

[Crumpp]

If Crumpp wants to continue with his time wasting obsession over the Spitfire's elevators

GEEZUS!!

How many time does it have to be said!!

There is nothing in that snippet:

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

That contradicts the NACA conclusions! You confuse the comments on LONG PERIOD OSCILLATION with the SHORT PERIOD OSCILLATION measured by the NACA and noted by the RAE!!

Not the same thing...APPLES and ORANGES!!

[5./JG27.Farber]

Did I misunderstand?

Originally Posted by ATAG_Bliss

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.

Originally Posted by NZtyphoon

+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.

I agree with Bliss but...

Lets read the 3rd point again...




Seems it will damage the pitch which will return to fine and then overspeeding of the engine that will cause the damage.

Originally Posted by Robo.

Very well! I'll do that at some point (if no one is faster).

Maybe I should put it up then or it will never get done?

[ATAG_Snapper]

Originally Posted by 5./JG27.Farber

Did I misunderstand?






I agree with Bliss but...

Lets read the 3rd point again...




Seems it will damage the pitch which will return to fine and then overspeeding of the engine that will cause the damage.




Maybe I should put it up then or it will never get done?

I thought the overspeeding prop after an engine cut was already modelled in this sim. Seems I have to quickly reduce throttle or the revs quickly climb above 3500+ when the engine restarts. Am I wrong on this?

[5./JG27.Farber]

Originally Posted by ATAG_Snapper

I thought the overspeeding prop after an engine cut was already modelled in this sim. Seems I have to quickly reduce throttle or the revs quickly climb above 3500+ when the engine restarts. Am I wrong on this?

You guys would know better than me but as Robo is a red pilot 1st I thought him offering to add it as a bug / feature ment it was not.

Ive just been thinking about it actually and it applies to a CSP. Is this not an automatic pitch propellor? What mark of engine is this manual for?

Trying to research this myself but red stuff is all new to me, found this:

http://spitfiresite.com/2010/06/batt...ropellers.html

[NZtyphoon]

Originally Posted by 5./JG27.Farber

You guys would know better than me but as Robo is a red pilot 1st I thought him offering to add it as a bug / feature ment it was not.

Ive just been thinking about it actually and it applies to a CSP. Is this not an automatic pitch propellor? What mark of engine is this manual for?

Trying to research this myself but red stuff is all new to me, found this:

http://spitfiresite.com/2010/06/batt...ropellers.html

The Pilot's Notes General don't apply to any particular mark or make of engine, they were issued to all pilots and used in conjunction with the Pilot's Notes issued for different aircraft types and models. The PNs Gen comments on propellers and overspeeding:

[5./JG27.Farber]

Originally Posted by NZtyphoon

The Pilot's Notes General don't apply to any particular mark or make of engine, they were issued to all pilots and used in conjunction with the Pilot's Notes issued for different aircraft types and models. The PNs Gen comments on propellers and overspeeding:

ok so whats the date of publication of this article?


Snapper, Dutch and Osprey I take it from your sarcasim that you object to having any negative flight model aspects added even though you constantly cry for a better, truer and more historically accurate flight model. I find it kind of odd when someone else makes a point that might add a realistic characteristic that you belittle the entire thread. Lets just get the facts so we can present them! Not sustain the red vs blue stance.

We can go over the 109 after if you like, I would enjoy that more. The narrow track landing gear physics do not operate as I have read them (when one wheel is on the ground and the other is not which causes the grounded wheel to move toward the centre - turning the aircraft over) for starters.