Why still no dive acceleration difference?
 

:confused:Dear All

Why thru so many versions still the very big defect--same dive acceleration

for all aircrafts---is not fixed?

As we know, FW,spit,p47,la....and so on have their own respective dive
acceleration which to some extence dominate the result of the combat.

It is really uncomfortable when diving in a Fw with a La almost neck to neck

Why it is not fixed, is it because of the limit of IL2 engine?

Because in game, g applies the same to all aircraft. Just like in real life.

thanks for concerning

however i want to correct u

G does affect everything on earth the same

however the air friction does not, plus the motor power, the shape of the plane, the weight of the plane

with the air friction, the feather obviously can not reach the ground as fast as the stone ball.

this make dive acceleration very different.

please go WIKI if u do not fully understand

also it has been record in RAF documents for the acceleration difference test of different spit fire. a lot of doc support those differences.

And thru the BBC history, u can clearly hear the old pilots saying their P47
can easly catch up with the FW190 when diving which other lighter planes can
not, even D9 dora can not compete the diving acceleration of P47

I do appriciate D team's effort

and love so much the IL2 sim which brings me a lot of fun

However, to be serious

IL2 will forever be a HANDICAP without this problem fixed

almost 10 years since the publish, man, I am slightly not patient enough now

But the diving speeds do vary in Il-2. Plus you can't compete with say a Lavochkin fighter against a 190 as you'd lose parts of your aircraft when diving too fast anyway. With all due respect I don't understand what you mean, perhaps you can give an example (starting altitude, engine settings etc).

I meant the speed increase difference in certain period during diving.

for example, spit early type may have speed increase from 200KM/H to 400KM/H in 10 sec during diving
while spit late type will have the speed increase from 200KM/H to 500KM/H in 10 sec during diving at same altitude and throttle condition

In 4.11 ver and before, La will share the same speed increase with FW 190 when chasing after it till critical speed limit during the diving

It's a bit late here, I will post the test documentation from from archive tomorrow

Hope this explaination can help to clarify.

Have you actually done tests in-game or are you just thinking that this is the case? I'm not trying to be obtuse but years ago I did some testing with a couple of players side by side and there was an obvious difference between different types of aircraft. It wasn't quite as pronounced as some people thought they would be... but it was there. I wish we still had the tracks but this was years and years ago.

I agree.

Only a couple of weeks ago a squad mate and myself were practising for a SEOW mission (HSFX i know, but), and we were testing how to best fight J2M's up high in a 47, and we did some side by side dive tests. All planes do not dive the same for sure.

please please

now set a quick mission

altitude 2000.

u will find Fw190A9 1944 be at 720km/h before hit the ground with 100 throttle

try La5 1942 same, 720km/h before hit the ground 100 throttle


please do that test. it is easy and fast to prove the defect

also please remember to press the "pause" botton before crash

please please try it from 10000m, and see the difference.

I am serious, do not take it as a joke

Please go WIKI if u do not understand what i am talking about.

Sorry for anything offensive

please also go Il2 compare to check La5 1942 and Fw190A9 ---- altitude vs TAS

U will really support me if u read the diagram and understand the difference.

"La5 1942 can not compare Fw190A9 in TAS at all Altitude except within 2km steep diving."

does it sound rediculous?

also please make sure u understand the difference between

diving speed limit

&

diving speed acceleration

I do understand the difference. i also understand that 2000m is not enough to show much, and that its not just the speed at the bottom, its the time to get there. Put them both side by side with to people in, and do the test from higher, and then come back.

It may well be that it should be more pronounced, but you will notice differences.

I think you are incorrect

1. 2000m dive for la5 1942 will increase it's speed from 260km to 720km which is it's limit
more distance is meanless, it will be shreded into pieces.

2. certain distance of 2000m, fixed speed at the start (260km/h) and fixed speed at
the end (720km/h), the acceleration rate is FIXED,
u can not reach the same speed by the end with different acc. rate, isn't it?

3. the case u mentioned diving from 10000m and see the difference does not because
of the acceleration, may be it is because of the speed limit.
limit of la is 720km, 860km for 190A9.
La of cause can not follow you thru out the diving if you start from 10000m

4. my point is: the distance between la5 and FW should be increasing once start diving
instead of maintaining the distance till the critial speed limit of La5

Well i'm certainly not from tests myself and DD_squawk did with respect to J2M's and P47's, we noticed one plane pulling away from the other, way way before the Vne of either plane.

Unless you have the 2 planes side by side, you won't and can't see it, have you tried this with someone else?

Well

I have suffered a lot in dogfight server in which I was caught up by La with same E stage
under 3000m.

That's why i start to reseach this issue~~~:)

dear D team member / admin

please see the fomular

set:
accelerate rate= a
starting speed=v0
end speed=vt
distance=x

The accelerate=a=(vt^2-v0^2)/(2x)
=(720km/h^2-260km/h^2)/(2*2000m)
=8.7m/s
=almost just G itself

this is the dive accclerate rate for everything in IL2,

for every bomber and piston fighter,

for both feather and rock in Il2 if any.

so simple and unrealistic

is this all we got in IL2 even in the future?

wrong post, pls delete, sorry

I did a test, 90° dive at 5000m, 30% fuel, default weapon,
accelerate time 300km/h~700km/h:
LA5FN 12.43s
FW190A6 12.95s
P47-D27 12.25s
TEMPEST MK.V 12.23s
almost the same?

it's a shame to P47 and TEMPEST

yes I am agree with that.

It is a shame to all heavy interceptive fighters

think about it :

One of the biggest advantages of these heavy fighters is to dive to get
the speed advantage and then pull into a hammer action verticlely,

However, these heavy fighters are emasculated so far in all versions

Up to level top speed, the better climbing plane accelerates better. Looking at the planes given, based on level speed and climb rate, the order should be Tempest, P-47, La-5FN and Fw 190A-6 and the differences small. All true.

If you want bigger differences, don't dive vertically, use a shallow dive, and try higher speeds. Take a Fw 190A-9 and a Spitfire IX 25lb, start at 550 km/h at 1.5km altitude and dive them to a place 15 km away. Check their speeds.

In TAIC test between the Zero and P-47 when they started the dive from 10000ft at 220MPH IAS and dived until Zero reached maximum allowed speed (325MPH IAS). It took 30 seconds for that and the P-47 had 100 yards advantage over Zero.

Disapointing, isn't it? :grin:

100 meters is close enough to get shot down.

I guess those planes are only good divers if they're fast to begin with. You should never be slow in a P-47. If you're at the same speed as a Zero, you've already lost.

These aircraft are not all that much different. They are similar in size weight power and performance, it only makes sense that they perform similarly, besides a vertical dive will be measuring the effects of gravity much more than any other factor.

As for relative performance in a fight, how the pilot uses the strong points of his aircraft against the weak points of his opponent is much more important than the actual performance. I get my butt kicked by guys in inferior aircraft all the time because they are better pilots.

S!

In situations with me flying a Zero vs. a Spit or P-47 or whatnot, if we start in same E situ me in the six of the other plane (where else ;) ), they always easily extend away after a short dive. I almost never get near the Vne because of the slow acceleration.

Zero is a kite that just doesn't have the mass for the dive acceleration and it clearly can be seen in-game.

yes, should have been more pronounced

I do not agree

1. cut wing and round end wing are different very much from each other
2. power are different, Tempest has 2000 HP while Zero has only 1200 HP.
3. weight for La is around 2000kg when FW is 4000Kg or more

I dont think they can perform in the same way during the diving

how about La5, it is also a light plane with out mass enough to perform
a fast dive....why i can not get rid of it in FW till it reachs it's critical speed
limit??

TAIC is "Technical Air Intelligence Center".It was established Washington, D.C. (Anacostia) in 1944, as a joint Army-Navy organization with British participation. To this center was assigned the responsibility of collection, evaluation, and dissemination of all technical intelligence on the Japanese Air Forces.

That's why they tested P-47 and Zero (lot of other planes as well) and 100 yards(~100m ) was the difference between real planes in test. If you think that difference should be bigger than maybe you have to adjust your expectations to match the reality.

Diving vertically down? Or at what angle to the ground?

From the top of my head, 30 degrees.

We all here agree, that real life rarely meets our expectations. Particularly, when someone thinks, he is wa-a-ay much better pilot, then he actually is. :lol:

The only person I heard talking about the Zero was talking about real pilots flying real aircraft during a real war.

The aircraft that you were talking about were contemporary competing designs which in the big picture had similar overall performance, that was what I was referring to.

Now please go ahead and and continue arguing the same point ad nauseum for our amusement.

LOL, what he said.....a man's got to know his limitations.

[Smart@ss comment] Maybe they measured the distance between the two impact craters. http://usefulshortcuts.com/imgs/skyp...136-giggle.gif [/Smart@ss comment]


;)

I've posted this before but for the OP and others who seem to have little idea: The soundtrack is great BTW.

http://www.youtube.com/watch?v=_NWaHlnI_LQ

Badaim, Saqson

Teasing and joking doesnt help you to improve yourself:-x

I am not here without proof or prepare

why can not you guys sit down and do the reaserch seriously

What u r laughing only shows your ignorance

I am disapointing with your "senior member" title

u will have to calculate a lot of factors before you can laught at me

shape, zero floating resistance, engine power, weight, propeller type and condition, deformation for the plane at different speed...and so on

Who were laughting at this topic are really simple mind and ignorant

I am here to help to improve IL2, to provide simers the best expierience,
instead of seeing some jokers.

--------------------------

--------------------------------------------------------------------------------

D team member, and who do not want to be the joker

Please check this like for ME262 compare documentation

http://www.wwiiaircraftperformance.o...erman-jets.pdf


and do the test in the Il2 4.11

here is the test in IL2 4.11 for the diving

starting altitude 5000m, throttle 100, stating speed 300km/h,
testing scope : 300 to 700 km/h

the result is below

Bf109G6as： 12s

Me262：11.7s


Isnt it showing something ridiculous?

D team member, and who do not want to be the joker

Please check this like for ME262 compare documentation

http://www.wwiiaircraftperformance.o...erman-jets.pdf


and do the test in the Il2 4.11

here is the test in IL2 4.11 for the diving

starting altitude 5000m, throttle 100, stating speed 300km/h,
testing scope : 300 to 700 km/h

the result is below

Bf109G6as： 12s

Me262：11.7s


Isnt it showing something ridiculous?

-----------------

please show your link of the documentation or so

Is it a memior or serious testing documentation?

I have docs showing the diving difference between different aircrafts

in game test we clearly found that the almost verticle diving will cost only

12 seconds from 300km to 700km

what will take "30 seconds to gain 100 yard"

what kind of steep dive will take 30 seconds???

D team member and Non jokers

the pic below will talk

http://www.wwiiaircraftperformance.org/wade-dive.jpg

http://www.wwiiaircraftperformance.org/wade-data.jpg

Not withut (a) telling us where the initial document is from, and (b) telling us what it is supposed to represent.

And what the heck has the second image got to do with dive acceleration rates?

Either find some data from actual tests on real aircraft that proves the Technical Air Intelligence Center results are wrong, or drop the issue. So far, all we have had is speculation and waffle from you.

The second image is showing the details of the planes only, the first is showing the diving diffrerence, and obviously it is not dive speed limit

you want to improve the Il2 or u want to win some dispute?

I have other souce showing the difference,

you can apply the same question to all source i provide coz it is internet.

if you do want to win a dispute instead of reaserching ,

let me tell you

you WIN!!!


I propose these only because I LOVE IL2


Thats all

Go away, do the research. Provide the evidence, then bring it here. Real evidence. With actual data describing the results from properly defined tests. Not pictures that tell us nothing at all.

Or f*** off and troll somewhere else.

Here's one more real life disappointment for you:
Who cares?

Really good, the one who do the reaserch and help to improve

deserves f*** off somwhere

really well, this is the way you treat serious people

Really nice

I found the potential problem, and come to 1c, to D team, to see some
help i can provide or some improvement can be made

I even spend time to serch the net and do the test myself.

now, Instead of being listened and think again and double check

I deserve f*** off

Really nice,

what a real simer

no problem you dont respect yourself, no one else will

I found the potential problem, and come to 1c, to D team, to see some
help i can provide or some improvement can be made

I even spend time to serch the net and do the tests myself

Now, instead of being listened and thinking again and double check

I deserve f*** off

Really nice,

what a real simer

Could some kind moderator please lock this pointless thread, and preferably block the clueless troll?

let me see if it will be locked

Let someone reasonable judge if this is point less

The one who raise the personal attack should be BANed indeed

Let me tell you

some other groups/teams now are seriously treating the diving issue

acutually it is not a easy issue to be solved.

it is very very complicated issue may invole IL2 engine defect.

I tell you again, I am not someone who wander around for nothing

I am here coz I lay hope to Dteam and Il2

and baning someone for saying something real but not comfortable is the Freedom institution your country so proud of?

you attacked me and u want me baned. woo....

No. Telling clueless trolls to f*** off is what my country is proud of. :-P

TAIC is very serious, have you read what I wrote about it? Report that deal with A6M5 and P-38,P-51 and P-47 is TAIC report No 38. A6M5 was tested against some Navy planes too,F6F-5, F4U-1D and FM-2. Results are published as TAIC Report No 17.

So far you didn't provided any evidence that would suggest that there is something fundamentally wrong with the game. IIRC Your picture that shows dives is from the post war magazine article.

And you will be hard pressed to find any RL test with planes diving at 90 deg straight into the ground or any 90 deg diving test for that matter, ~45 deg maximum angle during the dive is more typical.

I would like to advice you;

the best way to avoid telling the wrong one to f*** of

is to read more book and start calculation.

would you please show me the link or so, I am new here

I am not here to attack someone

acctually I will be happy if I am proved wrong coz I will not have to be
plaged by this issue anymore and can fully enjoy the Il2

However, thru my/our calculation, things are different with those shown
in Il2

acutually, I do not believe the 45 degree dive is similar to 90 degree seriously

and this is the the blank point we are trying to figure out.

Fw 190 defence action will always start with a split s followed by a certain period of almost 90 degree dive

so the veticle dive has it's meaning

letme show you some clue here

with the speed increased, the back-drag force will increase pronouncely
due to 1, deformation , 2, propeller pitch, 3, propeller tip speed,4, air wave darging force.

with this backward force increased largely.

the heavier aircraft should prevail in the diving.

roughly it is the result I got, and I am quite comfident it is meaningful
and to some extence correct.

rofl!

I am not native speaker, but i am trying to solve something

the point is to express

you'd better continue to wish I am baned

by the way

can you speak Chinese well?

No. But you are trying to communicate in English - and failing.

sounds u r happy to find this

instead of finding some truth

mayshine, I've recommended you to do this test:Have you done it?

I can also assure you that the issue has been brought up again and again over the years and that il-2 is fairly accurate at typical combat speeds. The limitations will be reached only when you reach very high speeds, where the effects of near sonic flight are not as strong as they are in real life.

I fairly know this, I start Il2 by 2004,

of cause spit will lag behind when it is closing to it's limit and start shaking

but

what I want to propose is fast and verticle dive

a intensive speed increasing dive, u sure they will perform in the same way?

obviously 15Km is not a steep dive

by the way

even one man I knew who knows Oleg and now part of paticipation of the "world of Plane"

he doubt the steep dive in IL2

In terms of physics:

dive acceleration = earth gravitational constant + excess thrust / mass

It is easy to see that as long as excess thrust is larger than zero, mass will reduce the planes acceleration. Excess thrust will be less than zero when the plane is above level speed for that power setting. Also, in typical flying conditions, earth gravitational constant >> excess thrust / mass, so excess thrust / mass doesn't really matter.

If you don't care about physics, at least search for the TAIC test FC99 mentioned, read it, and adjust your expectations. That time would be a lot better spend than making another dozen posts on the issue here.

Good , finnally I found some one who pose the formular

but I want to correct u in some point

G actually the advantage to heavy planes

see my formular posed previously.

F= ma, a=(m*g - back force)/m

when the backward force become larger and larger

the mass * G will become more and more helpful to speed up the plane.

that means the plane will bigger mass and less back force will be faster

and the back force is complicate,

it is regarded to the strenght of the plane, air wave darg force, pro pitch
propeller tip speed, the shape of the wing, wing load and so on

I dare not to simplify all this in to a univeral A = 8.7m/s as I calculated
previously

Do you still think I do not know physics?

to make it more obvious

set g=10, m = 10 , back force = 50

first plane mass = 2m
second plane mass = 1m

F=ma

a1: a2
= (2m*g-backforce)/2m : (m*g-backforce)/m
=150/20:50/10
=7.5:5

a1 is 50% faster

So in this extreme case plane have 2,5m/s advantage in acceleration. What will be the difference in distance after 12-13 seconds?

And in the end try with different values for drag for each plane like it is in most real life cases.

I just put everything simply in to the "backforce"

even the air fricition and what so ever are supposed to be within the "back force"

and

if the missing drag u mentioned is the drag force by the engine

JTD have already said Mass*G >> engine thrust or so

"earth gravitational constant >> excess thrust / mass, so excess thrust / mass doesn't really matter."

he is wrong?

I edited my previous post I wrote first version before you posted the calculation with "backforce". As you can calculate than do the full calculation and show us the results which proves how the game is wrong.

Just out of curiosity, how much difference you expect in dives?

come on!!!

in this extreme case it is not 2,5m/s advantage

its 50 % speed acceleration advantage

se FW = a1, La = a2
by the time la dive to from 300 to 500km/h , FW will get the speed of 600km/h

enought to do a verticle hammer action.


u know I can feel a lot of people are just defending theirself instead of
looking for truth

sorry I am not sure, but certainly will be different for current version

please do not be offenced,

you know I just try to........

acutually i am happy to be wrong

However I will try to provide more figures in the coming days

so late here now

yep, and it is only valid for 90 degree dive. You will have to multiply gravity force (mxg) with sine of the dive angle (assuming zero degrees of AoA) in a very simplified case. In the end, the final effect is marginal as tests show and as it is correctly modeled in Il-2 that has the basic physics 100% right.

I should be more precise and use m/s^2, I meant acceleration in my post and I still call it just 2,5m/s^2.

Even with this numbers distance between the planes will be less than 200m. Now plug in real numbers for FW and La and do the calculation again. When you include real numbers for mass, drag and thrust difference between La and FW will be very small.

LOL! You are so funny Mayshine. You tell us we aren't listening, and we don't know what we're talking about, but you have not listened to a bloody word anyone has said here, then you have the unmitigated gall to say that you would be happy to be proven wrong. That's Bull.

You are engaging in mental masturbation, pure and simple.

Have fun.

1)FC99, 30 degree dive is very different from 60 degree dive,leave alone 90 vertival.

http://www.wwiiaircraftperformance.o...e52-taic38.pdf

P51D and zeke，@10000ft，begin dive at 200MPH（IAS），after 27s， reach 325IAS ，P51D is 200 yards ahead of zeke。

This test is probably a shallow dive(30 degree), in my opinion, if dive in 45-60 degree, P51D will get much more advantage. So we need more data on 45 degree dive.


2)

http://www.wwiiaircraftperformance.org/sl-wade.html


As speed building up, the drag force of airscrew increases sharply because the tip of airscrew is approvching sonic.

Does il2 model this increasing drag of propeller? Does il2 model enginee exhaust gas boost at high speed?

3) http://www.spitfireperformance.com/spit9v109g.html


In il2, Does bf109 outdive spitfire at initial stage of dive?

Accelerating from 200 to 325 the difference will be mostly the same, if diving for 27 s the difference will be bigger. However, in a steeper dive the limiting speed of 325 IAS will be reached sooner, therefore you'll be diving for less than 27 s, and separation will be smaller.

http://www.wwiiaircraftperformance.o...e52-taic38.pdf

page 3-4


There is a "zoom"(should be nearly 90 degree upwards) test about P51D and Zeke with same cruising speed and altitude, side by side.


If il2-4.11m perfectly reproduce this "zoom" record, this thread's "boom" discuss can be closed.

Not really, as JtD already pointed, time is big factor here. If you dive vertically you will reach max allowed speed very fast and you will have not enough time to build big separation. And remember, when we are talking about planes like P-51 or P-47 and A6M5 we are talking about polar opposites of WWII fighter world.

That's basically the biggest difference you can expect and it is still not some huge separation some are wishing for.

Let's go back to mayshine's calculation for a moment.
Now let's put some real numbers for mass. I'll use FW190A5 and La5 values for mass. For now we will assume that drag(backforce) is the same although drag is somewhat higher for FW, I'll use drag = 4000 for both planes in time =0.
How much difference you can expect if they started the vertical dive from 2000m to the ground with starting speed = 260 Kmh?

Zoom is not necessarily 90 deg and in case of WWII fighters 90 deg zooms are mostly useless due to low power/weight ratio.

But again, difference is very small just 300 ft(~100m) from cruise flight up to 500ft after the zoom from dive. Considering that everything under 500m (~1600ft) is shooting distance for most Il2 players it is not enough to just put your plane into dive or zoom and expect that will solve all of your problems.

According to what? Your own personal expectations?

So what does this document tell us? "The condition of the Zeke 52 during test was good, so that significant comparative combat results were obtained, but certain airframe discrepancies prevented obtaining maximum speed and climb performance" - or in plain English, the Zeke tested was either underpowered, damaged, or both.

And what else do we learn? That this Zeke was slower in level flight than a P-51D, P-38J and P-47D. No surprise there. That it was more manoeuvrable at low speeds than the US fighters. Again, no surprise. But what do the dive tests tell us? That in the tests conducted, an underpowered/damaged Zeke can't out-accelerate the US fighters starting from 200 IAS or so. Zek vs P-51D, 10,000ft - after 27 seconds, when the Zeke reached 'red line' 325 IAS, the P-51D was 200 yards ahead. Not a lot, and presumably a 'good' Zeke would be doing better. Similar results with the P-38J. The P-47D out-dived this Zeke, but with less of a margin.

As for Blackberry's comments about vertical zooms, that is too ignorant to be worth commenting on.

FC99 do you know the drag formular?

I am working on it and found some problem in the speed.

I shall propose the result after double check


the formular is

Drag force (air friction to plane itself)

Drag= air drag coefficient*0.5*air density*air speed^2*wing demension

air drag coefficient should be the result from the lab and in Il2 data

can you just use the digit provided in Il2 software data?

coz your team are easier to dig out the date encoded

and see the difference in my simplified model between planes

(m*g-drag)/m

Good comment.zeke was lightly damaged.

BTW,the weight of a/c plays important role in a dive, the steeper the diving is, the more dive accelaration for heavier a/c.

In a steep dive, p47D may outdives p51d a liitle although p47's has less margin in a shallow dive than p51d over zeke.

Backforce increases sharply as speed build up. The heavier a/c is, the more ability of retaining high speed which is above a/c's maximum level speed.


In P51-zeke's test, they just did a shallow dive and then zoomed up. The zoom's beginning speed must be lower than 325PMH IAS.


At first, they zoomed up from cruising speed,that was 210MPH IAS=250MPH TAS, when P51d reach 130MPH=150MPH TAS, zeke was 90m lower. So how much kinetic energy was spent to get altitude?

0.5(250^2-150^2)= 20000

If they begin from 325MPH IAS=389MPH TAS

0.5(389^2-150^2)= 64410

We assume that there is a linear relationship between "kinetic energy" and P51D's zoom advantge to "damaged" zeke52.

So this time, p51d should be 3.22*90=290metres higher.


That is to say, when p51d @325MPH IAS@10000ft, and find a (lightly damaged) zeke on his 6 with same altitude and speed. And the distant between them are 450 metres. P51D may try a zoom, and will probably (450+290)=740m higher than zeke when p51d's speed drops to130 MPH IAS.

Surely 740m is enough for avioding being hit by zeke's cannon.

Forthermore, let's assume zeke could bear 450 IAS@10000ft, if they zoom from 450MPH IAS=539MPH TAS

0.5(539^2-150^2)= 134010=6.7 times of so called small "90m",that is 603 metres higher.

Surprising？Somebody will say zeke was underpowered and lightly damaged， I admit it， however， our caculating basis is on medium-low speed data, merely 210MPH to 130MPH IAS, it seems that p51d's zoom advantage will be more remarkable in high speed zooming, given by same amount of kinetic energy consumed.

Perhaps, p51d will gain sth.300meters advantage over 109 by starting a high speed (450MPH IAS)zoom, who knows? You can not simply deny that possibility.

FWA5 0,0236
La5 0,025

Why don't you just work backwards and calculate how much different planes should be for separation after dive to meet your expectations.
BTW how big the difference should be in your opinion after 2000m vertical dive?

If everything else is equal.

Distance between them will not be converted into altitude and if P-51 zoom at 90deg up as you suggested previously A6M5 will just cut the corner, use more energy efficient maneuver , close the distance to P-51 and in the end it will have nice fat P-51 close and slow right in its gunsight.

Happens online all the time.


Maybe, maybe not. Anyway, question is not about couple hundreds meters, it's obvious that some expects lot more than that. When you are slow on top of the zoom and enemy is 300 m behind you you are dead meat, more often than not and when that happens, it's not the problem with the game physics, it's pilot's error, as simple as that.

It has been known for years that the game accelleration rates are not that accurate. I think the documents from which the games rates are taken are from shallow test dives (as mentioned) so cannot really be extrapolated to 90 degree dives.

In this situation, there probably should be large initial differences due to weight, power and friction, as this was guaranteed escape tactic for the FW, P47 and others, against the lighter aircraft. Maybe TD can tweak the FM's in this area.
:)

Acceleration rate in dive is product of thrust, gravity and drag. Same equations are used no matter the plane attitude. Gravity is the same in the game no matter what the plane is doing. Thrust and drag are inside reasonable margins under level flights and climbs so there is no reason to believe that they are wrong during dive, especially during the initial phase.


We could but we prefer to have FM as realistic as possible.

The final test would be P47-vs-something else.

We all know that the p47 'dropped like a brick'... if this doesn't happen in comparison to other a/c... we quiet simply have a FM problem .. period!
;)

This is a valid, if not 'niche' point brought up by mayshine.. whether anybody likes it or not, is irrelevant.
and..
Yes Yes.. we've done the aeronautics and formulae ad-nauseum ;)

Interesting.... and you actually believe this statement to be the 'absolute truth'

It is time to rethink FM policy... :)

Based on guesswork, or data?

Actually, it's not "we all know", but "some think". I know that it dropped faster than a brick, and it does in game. A brick neither produces the thrust a P-47 produces, nor is it anywhere near as aerodynamic. However, this applies to about all WW2 fighter aircraft.

Anyway, you are more than welcome to do the research, dig up a few tests and take it from there.

especially during the initial phase.............

I have a question, does bf109g6as outdive spitfire IX or fw190A8 during the initial phase in 4.11m?

Is this data correct in 4.11m?
 

Bf-109-G2
[Mass] kg
Empty 2320.0
TakeOff 2830.0

[Squares] m^2
Wing 16.16
Aileron 1.02
Flap 2.00
Stabilizer 1.90
Elevator 1.20
Keel 0.70
Rudder 1.10

[Polares]
lineCyCoeff 0.094
Cy0_0 0.15.............................................. .
AOACritH_0 21.0............................................
AOACritL_0 -16.0...........................................
CyCritH_0 1.48.............................................. .
CyCritL_0 -1.0230048.....................................
CxMin_0 0.027............................................. ..
parabCxCoeff_0 6.7E-4....................................

Spitfire.LF.IXC
[Mass]
Empty 2650.0
TakeOff 3300.0

[Squares]
Wing 19.0
Aileron 1.32
Flap 2.125
Stabilizer 1.90
Elevator 1.20
Keel 0.85
Rudder 1.10

[Polares]
lineCyCoeff 0.092
AOAMinCx_Shift 0.0
Cy0_0 0.1
AOACritH_0 16.0
AOACritL_0 -17.0
CyCritH_0 1.4
CyCritL_0 -0.7
CxMin_0 0.0232
parabCxCoeff_0 5.4E-4


P-47D-27
[Mass]
Empty 4630.0
TakeOff 6583.0

[Squares]
Wing 25.87
Aileron 1.45
Flap 2.76
Stabilizer 3.50
Elevator 2.05
Keel 1.30
Rudder 1.10

[Polares]
lineCyCoeff 0.092
AOAMinCx_Shift 0.9
Cy0_0 0.17
AOACritH_0 16.0
AOACritL_0 -15.0
CyCritH_0 1.25
CyCritL_0 -0.8
CxMin_0 0.0256
parabCxCoeff_0 4.8E-4


Bf-109G-2 = 0.027 * 16.16 = 0.43632
Spitfire.LF.IXC = 0.0232 * 19.0 = 0.4408
P-47D-27 = 0.0256 * 25.87 = 0.662272


Bf-109G-2
0.43632/2830 = 1.5417667844522968197879858657244e-4

Spitfire.LF.IXC
0.4408/3300 = 1.3357575757575757575757575757576e-4

P-47D-27
0.662272/6583 = 1.0060337232264924806319307306699e-4

Tell me you don't touch any of the flight models.....

Excess thrust......not the same!

:rolleyes:

Mayshine's question has been answered, dive acceleration difference exist in game already.

And P-47 falls like the brick in comparison with most other aircrafts.

Depending on initial conditions and your definition of "initial phase" that's probably possible.

FM data you posted for several planes looks like 4.11 data.


And JtD is wrong in what exactly? AFAIK F=mg, g is a constant and is the same for every object in game.

Of course it is Fatcat. This is not the issue and completely irrelevant as to why your FM's would not exhibit any differences in dive acceleration. It does not answer the original poster's question.

Take the force triangle for a dive. A component of weight contributes to thrust based on the angle of dive. The difference between the force on the axis of motion in the dive and the force on the axis of motion for level flight is your initial excess force that will move the aircraft to its new equilibrium point velocity. The derivative between that and equilibrium is your average excess force along that vector....

Then apply the same formula...

Force = Mass x Acceleration

Rearrange it to solve for Acceleration: The acceleration of gravity is considered constant but acceleration is not constant.

Acceleration = Force/Mass

You then have the aircrafts acceleration rate to the equilibrium point.

Now I am not a computer programmer but I am sure there is a way to look at the code to see if it following those principles.

But it does. The original poster asked in the topics title why there are no dive acceleration differences. There aren't because gravity is the same for all planes. As soon as you consider anything else, the dive accelerations are different. Had he asked why all the dive accelerations are different, the question would have required a much more complex answer.
The answer was specifically given to the question asked.

The amount of excess thrust determines an aircraft dive acceleration.

The acceleration of gravity is constant but that excess thrust is not constant. It is a characteristic of the design and each aircraft will have a different acceleration in a dive.