True Altitude?

[Soldier_Fortune]

Originally Posted by KG26_Alpha

I'm pretty sure ambient temperature, at ground level at least, has been modeled for a long time.

The fact they produced a v4.11 "read me" showing map temps doesn't mean they were not present long before v4.11

Desert maps ambient temps were @ 80-90' back on v4.07 iirc
You only had to look at the temp gauge on your aircraft with the engine off on the runway to see ambient temperature was in the map.
Which was always a bit strange as the engine was cold but the temp gauge registered outside temp.

I can't recall if the ambient temperature was present long before the patch 4.11: frankly I never paid atention to the outside temperature gauges until several weeks ago.
Now I've the game updated to 4.12.1 and I'll not downgrade it to a previous version to check that.
Might be those gauges originally were present for 'flavor' purposes only, without any other appreciable effect on the game's behavior (it wouldn't be the first time nor the last we saw something like).
But the fact is the IAS/TAS charts show the outside temperature was constant, it being 0 ºC for any map and any altitude, and we know they worked perfectly.

As I was telling you, I never paid atention to the outside temperature gauges until several weeks ago. And it was accidentally: while I was testing a bomb mission flying a B-25, I looked at the TAS gauge in the bombardier post after setting the bombsite with the aid of the IAS/TAS chart, and I saw that there were significant differences between the two readings. And I thought: "Shit! Is it a new bug?"
After some calculations with the E6-B, I could see the TAS gauge's reading was true. And looking to the outside temperature gauge for my very first time, I saw that the reading matched that of the real atmosphere for that altitude.

I have conducted numerous tests to confirm this, flying different planes in different maps.

Air density at altitude is the interesting factor though it seems something had changed.

It is very important to understand that ground level temperature, altitude and density are closely related, and all together influences the TAS.

The standard formula for the air density at a given altitude below 11,000 m is:

AIR_DENS(Z) = AIR_DENS(0) * [(TGL + LAPSE_RATE * Z)/ TGL]^4.25

Where:
AIR_DENS(Z): air density at a given altitude Z
AIR_DENS(0): air density at 0 m ASL (1.22 kg/m3)
TGL: free air temperature on the surface (std temp = 288.15 ºK or 15.15 ºC). This temperature may be different than the standard temperature.
LAPSE_RATE: -0.0065 ºK/m, it is the constant rate at which temperature decreases with altitude.
Z: altitude ASL, measured in m.

So that formula explains why a plane, flying at a given altitude, may fly at a slower or faster TAS regarding of the Ground Level temperature.
The E6-B allows a pilot to calculate the TAS in one step, knowing the outside temperature, the indicated altitude and IAS: he doesn't need to know or to calculate the air density.

A word form TD would be enlightening.

+1.

[hafu1939]

As a FMB user trying to replicate real WWII events I need to calculate with TAS in flight plans. I use since 4.11 a freeware utility called AtmosCalculator. You can find it here: http://www.newbyte.co.il. This calculator is satisfactory for the use in Il-2, I hope it can help to solve your problems.

[Soldier_Fortune]

Originally Posted by hafu1939

As a FMB user trying to replicate real WWII events I need to calculate with TAS in flight plans. I use since 4.11 a freeware utility called AtmosCalculator. You can find it here: http://www.newbyte.co.il. This calculator is satisfactory for the use in Il-2, I hope it can help to solve your problems.

Hi hafu1939!

Thank you for to share that tool with us.

But if you are a FMB user, surely you will need to considere the wind speed and its direction also (well... it's if you are including any wind in your designed missions).
In such case, the E-6B would be almost a 'must have': with that tool you will can calculate a lot of things relative to the flight.

In this link you will find general information about the E-6B: http://en.wikipedia.org/wiki/E6B

Following this link you can download de user manual of the E6-B in .pdf format: E6-B Instructions

And in this link you'll have a realistic on-line simulation of the E6-B (it's a bit tricky to use: with left click and dragging you can move the disks; and with right click you can zoom it in and out): http://www.pilotinside.com/images/tools/e6b/e6b.htm#top

Give it a try, and let me know if you find it useful.

Have fun!

[KG26_Alpha]

I use Pilotwizz app on my Iphone

[Soldier_Fortune]

Originally Posted by KG26_Alpha

I use Pilotwizz app on my Iphone

Good!

That app has many of the features of an E6-B... and surelly with it you can compute faster than me.

However to recreate the enviroment of the '40s, for me my E6-B, a printed map, a pair of pencils, my plotter, and a song of Glenn Miller or the Andrews Sisters, are essential. LOL

The main difference between the app and the E6-B is you can use your iPhone inflight, wihile I must pause the game for to make my calculations, because I need my two hands to handle the E6-B.

Please, when you can, have a look at the links I've posted before.

[KG26_Alpha]

Im very familiar with the Wizz Wheel E6B

I just find it so obsolete (slow) for IL2 1946, with "Pilotwizz" I can use it on the fly very quickly

Also

The test maps from earlier in this thread >>> http://forum.1cpublishing.eu/showthread.php?t=40740 I used are showing @ -5' temp at @ 4000m

This still calculates from the tables as I have been using for years.

270kph ias
330kph tas
4000m alt
OAT -5'C

So somethings making them drop long if all the calculations are correct...........What inputs are the AI using for their bombing routines, as they don't seem to have a problem ?





.

[Soldier_Fortune]

Originally Posted by KG26_Alpha

Im very familiar with the Wizz Wheel E6B
...
Also

The test maps from earlier in this thread >>> http://forum.1cpublishing.eu/showthread.php?t=40740 I used are showing @ -5' temp at @ 4000m

This still calculates from the tables as I have been using for years.

270kph ias
330kph tas
4000m alt
OAT -5'C

So somethings making them drop long if all the calculations are correct...........What inputs are the AI using for their bombing routines, as they don't seem to have a problem ?

.

Hi KG26.

After reading your last post, I've conducted a test for each of both maps mentioned in that treath: Crimea and Moscow1 (winter).
I've done them with a B-25J because this aircraft is equipped with all the relevant guages for these tests: OAT, IAS/TAS, and Altimeter.

The payload were 2 x 1000 lbs bombs, being the targets:
- Crimea: a ring target placed in the air base of Simferopol (altitude = 800 ft =243 m ASL).
Moscow: the same type of target at the same altitude ASL, placed in the air base near to Vyazma.

The following data were obtained from the gauges readings (none was calculated, except the speeds in km/h):
CRIMEA:

- Wind speed = 0
- OAT at GL: 25 ºC
- Altitude during final approach to target: 13050 ft = 3970 m
- OAT at level bombing: 0ºC (should be -1 ºC)
- IAS = 160 mph = 258 km/h
- TAS = 200 mph = 323 km/h

MOSCOW WINTER:

- Wind speed = 0
- OAT at GL: -17 ºC
- Altitude during final approach to target: 13615 ft = 4150 m
- OAT at level bombing: -40ºC (should be -44 ºC)
- IAS = 160 mph = 258 km/h
- TAS = 186 mph = 300 km/h

Comparing this readings with the IAS/TAS charts, the data of the Crimea map are quite similar to them. The reason: the OAT at that altitude presents an irrelevant difference (-1 ºC).
But the outcomes obtained in the Moscow Winter map are too different when they are compared with the charts, due to the OAT differences as at GL as well as at flight altitude, like it is expected IRL.

I've engaged the Autopilot to have complete freedom for to read the gauges inflight, and because I was interested to see how the AI did do it.
May be an average AI bombardier is a bit idiot...the point is that it missed its targets in both maps, with the bombs falling too short and too far.

Anyway, I think the AI uses the gauges readings as inputs for the bombsite.

I have screenshots of the gauges in both missions. Tomorrow I'll try to upload them, and also I shall perform several flights in both maps to find out what data are the best to adjust the bombsite.

We will see the results... I hope.