Latest Patch - Spitfire Neg G changes

[SEE]

Just been testing the new patch and apart from all the other things mentioned it seems we have a change to the neg G.

Nose down engine stops - wait a second whilst keeping nose down and engine returns to full power.

Canopy closed view is much better.

[1./JG2_Miller]

I tested it one hour ago and put the nose of my spitfire down for about 5 secs. My engine somehow catched fire and seriously struggled to return to full power. After another 5 minutes it finally stopped working and I had to crash land into a field. It was also shaking like I just flew into Hurricane Irene. :-P

[SEE]

I cannot replicate that. I just tried the Spit on line - seems that the FM has been changed too. The Spitty handles very nicely and seems to have had changes to its stall characteristics as well as the neg G.

[sorak]

There could be still placeholders for unfinish sound also in the beta.. Maybe laterr on they will add more sounds to fill the gaps like they stated.

[David198502]

good to know about the negative g characteristics of the biritsh fighters now! i was complaining in another thread about hunting spits doing insane negative g manouvers.but that was ai.im glad to know that this aspect was reworked!!thx see for the info.

[SEE]

good to know about the negative g characteristics of the biritsh fighters now! i was complaining in another thread about hunting spits doing insane negative g manouvers.but that was ai.im glad to know that this aspect was reworked!!thx see for the info.

I don't know about the AI David but I find it easier to chase down with the new patch - you may end up posting again....:)

[Das Attorney]

Yes - good to see they've made the neg G cut out more pronounced. Really liking a lot of things about this patch.

[41Sqn_Stormcrow]

I haven't tried the beta right now but I hope we get back some of the Merlin sensitivity so that Clod Merlin does not feel as arcadish as old IL2 cut out.

For those who cannot handle realistic cutout an option for simplified cutout could be implemented and everybody would be happy instead of dumping down the sim aspect of the game for all.

[IvanK]

I haven't tried the beta right now but I hope we get back some of the Merlin sensitivity so that Clod Merlin does not feel as arcadish as old IL2 cut out.

For those who cannot handle realistic cutout an option for simplified cutout could be implemented and everybody would be happy instead of dumping down the sim aspect of the game for all.

What do you believe to be realistic cutout ? By that I mean cockpit indications, sounds and at what G should the symptoms commence ?

[TomcatViP]

I think it's just fine.

...and I am a flying for half the beast for half the Hurri :cool::cool:

[SEE]

I haven't tried the beta right now but I hope we get back some of the Merlin sensitivity so that Clod Merlin does not feel as arcadish as old IL2 cut out.

For those who cannot handle realistic cutout an option for simplified cutout could be implemented and everybody would be happy instead of dumping down the sim aspect of the game for all.


If you haven't tried it, what makes you think it's been dumbed down? :confused:

[ACE-OF-ACES]

Just been testing the new patch and apart from all the other things mentioned it seems we have a change to the neg G.

Nose down engine stops - wait a second whilst keeping nose down and engine returns to full power.

Canopy closed view is much better.
I didn't notice it comming back to full power.. But I do like the cut out effects.. reminds me of my old F100 when it started to run out of gas ;)

[IvanK]

I think it's generally pretty good, you hear a few sputters, the noise dies out, with it being too rich, maybe a few backfires would be appropriate, as the timing would be off as the engine dies down.

Luthier had stated a long time ago that their records indicated the cutout should commence at 0.5g, but they reduced it to 0.1g as far as I can remember. I think somewhere between these would be a better compromise.

This has been debated in this forum at length. As far as at what G does the cut begin at that is documented at 0.1G i.e a 0.9G reduction from 1G flight...i.e. getting close to 0G*. The RAE flew a bunch of instrumented aeroplanes to determine onset thresholds as part of a study aimed at curing the issue. Here is a page from the report. Its available in the UK National Archives as AVIA 13/234 :

http://img593.imageshack.us/img593/7585/vegcutfile2.jpg
This complete document is with the Devs.

[*Edit replaced -1.0G with 0G]

[IvanK]

Err not quite. G meters are accelerometers and in straight and level flight indicate 1G. As you start pushing they go towards 0G on the scale. Here is a G metre in a Yak 52 sitting on the ground i.e. at 1G.

http://img190.imageshack.us/img190/1876/gmeteryak521g.jpg


0.1G would have the needle just above the 0 mark. Anything less than 1 is a negative acceleration.

My typo in previous post (since corrected) that means the G meter would be just above 0G reading 0.1G when the negative G cut starts.

[41Sqn_Stormcrow]

If you haven't tried it, what makes you think it's been dumbed down? :confused:

The cutout was made old IL2-like in one of the first ever patches. I think we should have something inbetween retail cutout and what we have now. Currently it is too much like IL2 which just had a fake cutout sequence modelled.

While the retail cutout was a bit too sensitive (no inertia of the floater modelled obviously) it was basically the right approach I think.

[Crumpp]

My typo in previous post (since corrected) that means the G meter would be just above 0G reading 0.1G when the negative G cut starts.

In other words, the cut out is instantaneous once negative accelerations are experienced.

That is because ANY negative acceleration will cause an interruption in the fuel metering on a float carburetor.

[TomcatViP]

Accelerometer in automobile might measure lateral accelerations which are null if you are driving straight ;)

not such thing in a plane

[TomcatViP]

What do you believe to be realistic cutout ? By that I mean cockpit indications, sounds and at what G should the symptoms commence ?

May be a slight mvmnt frwrd of the pilot head each time the fuel flow is cut when the speed is high (>200mph) ?

[Crumpp]

Maybe its just the baseline is different, but a parked aircraft or one flying straight and level would still be experiencing 0 vertical acceleration right?

No it is under 1G acceleration just as you and I are sitting at our computers....

[Osprey]

Otherwise we'd all float off the planet.

As long as it'a accurate then it's all good. I would say that PC Pilots have a harder time because we are unable to feel acceleration and g, and stick sensitivity is more sensitive (ie I would rather have a 2ft stick from the floor and not a desk stick)

Splutters occur often when I trim, I need to change my trim solution because in 1946 it was fine, in COD it appears to actually work lol.

I thought that Das Attorney made a silly post. Just because they made it more pronounced and perhaps easier to chase down by your 109 should they make the mistake of cutting their engine does not make it an improvement. What matters is that it is accuracy even if that is to your disadvantage. If your objective is to make IL2 as easy as possible for you so that you have fun by winning all of your fights then just play offline with invulnerability, unlimited ammo and unrealistic ammo set up.

[whoarmongar]

I have no problem with accurate negG cutout, However I do have to question if a quick spike in negG would cause an instant fuel cutout. Surely the float chamber has some fuel in it when a quick spike of negG occurs? Perhaps the cutout shouldnt be so immediate, I dont know but I just think there would be a very short delay before the negG "event" occured.
I have read many pilot reports of neg G cutout when "bunting" the aircraft nose down, but I havnt read of anyone complaining of negG cutout when climbing and just trimming forward a bit to reduce the rate of climb, as modelled in CloD.
whilst on this subject surely after the fuel starve cutout there should be a overrich "flood" that causes spluttering and a cloud of black smoke (unburnt fuel) for perhaps a couple of seconds. does this happen in game ? I never fly external view but I cant say I have noticed the black smoke.

[Crumpp]

How long do you think a few ounces of fuel last's in a WWII fighter engine consuming 40-160 gallons per hour?

Even in a Lycoming O-360 A1A consuming 8-12 gph, the consumption is high enough and the cut out is for intensive purposes, instantaneous.

Certainly in a climb a float type carb will react if subjected to negative accelerations. In normal climbs, a gust or turbulence acceleration is rapid onset and very short duration so the skipping is not noticed by most pilots. If you have a digital rpm and manifold gauge or an EIS you will see it.

Bunting was a common tactic used by Bf-109 pilots to escape Spitfires on their tail in fact.

A bunt is just a maneuver involving a negative g pushover, especially in an air-to-ground attack or leveling out after a zoom climb.

[ATAG_Snapper]

I have no problem with accurate negG cutout, However I do have to question if a quick spike in negG would cause an instant fuel cutout. Surely the float chamber has some fuel in it when a quick spike of negG occurs? Perhaps the cutout shouldnt be so immediate, I dont know but I just think there would be a very short delay before the negG "event" occured.
I have read many pilot reports of neg G cutout when "bunting" the aircraft nose down, but I havnt read of anyone complaining of negG cutout when climbing and just trimming forward a bit to reduce the rate of climb, as modelled in CloD.
whilst on this subject surely after the fuel starve cutout there should be a overrich "flood" that causes spluttering and a cloud of black smoke (unburnt fuel) for perhaps a couple of seconds. does this happen in game ? I never fly external view but I cant say I have noticed the black smoke.

The black smoke occurs with both the Spits and the Hurries.

[TomcatViP]

Absolutely true ! The sum of external Force acting on a solid is null if the solid is at rest ;)

However when you say that you hve just pulled 5G it does not mean that you hve pulled 5g +1G of the normal gravity. It's only 5g (otherwise the G that you feel won't be the same if it was an horizontal turn or a vertical pull up). Then at level flight G =1 . Bank at 60 G=2 (see pic bellow)

By the way that where the Il2 spit was eating E ;)

PS: the neg G cut-out is just perfect : Don't make any modification for god Sake !

[Crumpp]

I most definitely am not accelerating while sitting at the computer. I may have two forces acting on me (gravity and the normal force of the chair pressing back against gravity), but am currently in a stable state of 0 acceleration.


You are under 1G acceleration sitting at your computer just as I am. You are also not accelerating just as you are saying......

How can that be???? :confused:

An airplane in level flight is under 1G. The force of lift provides the centripetal force required to keep the airplane at a constant altitude.

When our butts are planted in a computer chair, it is the chair and the ground pushing back against that 1G acceleration of gravity that provides the center seeking force to keep us on the surface of this spinning ball we call Earth.

Acceleration is change in velocity over time, which when you are sitting is 0m/s^2. By definition, when you are at rest, or traveling at a constant state, there is no acceleration.

Not when you are sitting on a round ball that is spinning....

The earth is spinning so by definition we are always accelerating...

Hence the acceleration of gravity!!! :cool:

Any motion in a curved path represents accelerated motion, and requires a force directed toward the center of curvature of the path.

http://hyperphysics.phy-astr.gsu.edu/hbase/cf.html

The confusion here is frame of reference. From your bodies Center of Gravity, there is a balanced force so you have no acceleration. From the Earths center of gravity, you are under a constant state of acceleration.

Back to airplanes....

G-meters are calibrated from 1G level flight....

http://www.aircraftspruce.co/catalog/inpages/flightdatafc50.php

Why??

An airplane in a constant altitude turn must ALWAYS offset 1G of force in order to maintain that altitude. Most of you are savvy enough on the physics to understand that lift equals weight in 1G level flight.

When our airplane turns, it must provide the amount of force required to meet the centripetal or center seeking force required to keep us on a curved path. Fortunately in a constant altitude steady state turn, this amount of force has a fixed relationship to angle of bank.

Otherwise, the simple calculus and math required to determine reasonable prediction of airplane performance would not be so simple!! :o

At 60 degrees angle of bank, we need produce 2 times the weight of our aircraft in total force to maintain a steady state constant altitude turn. One times the weight is needed to offset the acceleration of gravity and One times the weight to provide the centripetal force required to keep us on our curved path.

From the frame of reference of the our airplanes CG and thankfully, us as the pilot, we perceive these two different acceleration vectors as one. Even though the airplane is banked our butts still want to stay down planted in the seat. Our flashlight hung on the canopy latch still hangs down pointed at the floor.

If we look at our G meter, it reads a steady 2G, just as it should and all is correct in the universe!

How does a G-meter work?

An accelerometer is a damped mass on the end of a spring in its simplest form.

For example, a stationary, single-axis accelerometer is adjusted so that its measuring axis is horizontal. Therefore, its output will show G Force measurement to be 0 g, and will continue to be 0 g if it is placed in a vehicle moving at a constant velocity on a level road. But if the automobile driver brakes sharply, the accelerometer will give a reading of about −0.9 g, which corresponds to a deceleration. However, the jerk due to a change in motion in the vehicle and gravity pull of the ground on the accelerometer should not be looked at as the same thing.

But if the accelerometer is turned around by 90°, so that its axis points upwards, it will calculate G Force to be +1 g upwards even though the vehicle is still stationary. Here, the accelerometer is exposed to two forces: the gravitational force and the ground reaction force of the surface it is placed on. Remember that the accelerometer can measure only the latter force, due to mechanical interaction between the accelerometer and the ground.

http://www.gforces.net/a-comprehensive-guide-on-measuring-g.html

[VO101_Tom]

I most definitely am not accelerating while sitting at the computer. I may have two forces acting on me (gravity and the normal force of the chair pressing back against gravity), but am currently in a stable state of 0 acceleration.

Acceleration is change in velocity over time, which when you are sitting is 0m/s^2. By definition, when you are at rest, or traveling at a constant state, there is no acceleration.

Hi. Honestly, I do not understand what you ask. The accelerometer measures the forces, wich acting on the airplane, not the current movement of the aircraft. If the name confuses you, call it "G-meter". Its default value (standing or flying horizontally): 1. If you push the stick is reduced, when you pull increases. During inverted flight -1 ...

[VO101_Tom]

Gravity is not caused by the rotation of the earth, all mass creates gravity. The only thing close enough to us to feel is the mass of the earth, but large enough objects (i.e. the moon) also exert gravity on us. No, it has nothing to do with the moon spinning either.

Have you ever worked with accelerometer, it most definitely does not read 1g in a stationary car when turned on its side. Done here, not teaching physics if I'm not getting paid...

Ehh. Forget the cars. :)
The accelerometers measuring along the longitudinal axis in the cars, and along of the vertical axis in the aircrafts. If you working with car acc.meters, you have to do, just rotate it 90 degrees and you will see that there is 1G. In aircrafts was built that way because, the vertical forces can cross the structural load limits during tight turns or high speed maneuvers.

[Crumpp]

Gravity is not caused by the rotation of the earth,

Nobody ever said it was caused by the rotation of the earth.

Read again what I wrote in my previous post.

all mass creates gravity

Correct. And the distance from the masses center determines the centripetal or center seeking force required to keep you in the same spinning frame of reference.

:cool:

That is why you and your airplane lose weight when you gain altitude!! The farther from the center, the less center seeking force required. :-)

GRAVITY was explained by Isaac Newton with a formula that says two masses M1 and M2 are attracted to each other by a Gravitational Force. The Gravitational Force, F1, is calculated by the equation below:



F1 = G x M1/R x M2 / R



Where R is the distance between the center of M1 and the center of M2 and G is the Constant of Gravitation.



If you use metric units, M! and M2 are kilograms, R is meters, G is

6.673 / 100000000000 Newton-Meters per kilogram per kilogram, and

F1 is Newtons.



CENTRIPETAL FORCE, F2, is the force that pulls on a string if you tie a rock on the end of a string and twirl the string with the rock on the end around your body. The Centripetal Force is the force that pulls on the string. A similar thing happens when a planet orbits around the sun or when our moon orbits around the Earth or when the space shuttle orbits around the Earth. The smaller object revolve around the bigger objects. The string is like gravity.



F2 = M! x V x V / R



Where V is the velocity (speed) of the rock or satellite



If you use metric units, V is meters per second



ORBITS: A less massive object M1 can orbit around a more massive object M2 if the Centripetal Force of the orbiting object is the same as the Gravitational Force between the two object. If you look at F1 and F2 above, then there is an orbit if F1 = F2. Another form of this equation is



G x M1/R x M2 / R = M1 x V x V / R

Or the speed of the satellite, M1, must be V = SQRT (G x M2 / R)

http://library.thinkquest.org/3806/ORBMECH.HTM

[Crumpp]

Cheesehawk,


VO101_Tom is trying to help you. Listen to him as he is correct.

[touchdown42]

Thank you very much for the link.
very interesting video and it was a pleasure to listen to the old man telling stories from this time.

[Crumpp]

Interesting what a real pilot had to say about the Neg-G

Hey...:mad:

I am real pilot and I told you the same thing from the beginning!! :)

Seriously, great video and thanks for posting it.

[VO101_Tom]

Very interesting interview, thanks the link.