Finding outside air temperature

[Skinny_Huesudo]

Current OAT is crucial for calculating true air speed from IAS and viceversa.
AFAIK, careers show only temperature at ground level, and I've seen an OAT gauge in the He 111 only. Also, only the Me 262 has a TAS gauge.
Are there any other ways to finding OAT or TAS from the cockpit or without looking at the map?

EDIT: if map icons are enabled, finding out ground speed shouldn't be too difficult. IIRC, each grid square is 10x10 km, so you just have to time it and do a bit of math and conversions. But that's a bit cheaty, and some multiplayer servers don't have map icons enabled.

Edited January 30, 2020 by Skinny_Huesudo

[Yogiflight]

1 minute ago, Skinny_Huesudo said:

and I've seen an OAT gauge in the He 111 only.

Ju88 and Bf110 have it, too.

[MikhaVT]

Does Tacview have some way of reporting TAS? People were mentioning before that it could show G load.

[busdriver]

17 hours ago, Skinny_Huesudo said:

EDIT: if map icons are enabled, finding out ground speed shouldn't be too difficult. IIRC, each grid square is 10x10 km, so you just have to time it and do a bit of math and conversions. But that's a bit cheaty, and some multiplayer servers don't have map icons enabled.

 

Not a cheat at all...very basic RL fighter pilot knowledge. Feel free to clip this out and tape it to your monitor 

 

180 km/h (~110 mph) = 3 km/min; in 10 minutes you will fly 3 grid squares

240 km/h (~150 mph) = 4 km/min; in 10 minutes you will fly 4 grid squares

300 km/h (~185 mph) = 5 km/min; in 10 minutes you will fly 5 grid squares 

360 km/h (~225 mph) = 6 km/min; in 10 minutes you will fly 6 grid squares

420 km/h (~260 mph) = 7 km/min; in 10 minutes you will fly 7 grid squares

480 km/h (~300 mph) = 8 km/min; in 10 minutes you will fly 8 grid squares

540 km/h (~335 mph) = 9 km/min; in 10 minutes you will fly 9 grid squares

 

I'll let you figure out how long it will take to fly one grid square. 

 

 

 

 

 

Edited January 31, 2020 by busdriver

[Ram399]

It might be a somewhat crude way to calculate OAT, but you could get a rough estimate by using the ground temp and just walking it up the standard lapse rate.
I don't really know how in depth the temperature modeling goes for IL 2, but I'd imagine its not far off from -2 degrees Celsius per 1000 feet/300 meters.

In effect, under standard conditions a ground temp of 20 C should hypothetically be 18 C at 1000' AGL and then 16 C at 2000' and so on.
This would of course vary depending on a number of local conditions.
For example, the current METAR at my airport has the ground temp at 16 C, and winds aloft are indicating 12 C at 3000'.
That's 2 degrees warmer than it would at ISP, but considering that the current pressure is higher than usual at 30.04 in Hg it more or less fits (Woe to the man who tries to predict Florida weather anyhow).

For TAS you'd need pressure altitude, OAT which I think you'll have to get using the rough lapse rate method, and then just IAS.

Pressure altitude can be found using the field altitude, barometric pressure, and the temperature at ground level, all of which IL 2 luckily provides us.
Pressure altitude = (standard pressure - current pressure setting) x 1,000 + field elevation
Using the current in-game conditions from my IL 2 career for May 26th, 1943 at Anapa airfield this time:
Current pressure: 758 mm Hg (29.84 in Hg), Field Elevation: 49 m (160 ft)
PA = (29.92 - 29.84) x 1,000 + 160
PA = 240' at Anapa

So we'll calculate for my Bf-109 G4 flying at 2000 meters (6,561 ft) over Anapa, with a ground temp of 24 C roughly adjusted using lapse rate to 11 C, my IAS of 400 km/h (215 knots), and a pressure altitude of 6,641'
If we run that through the TAS formula (which I'm going to do on my electronic E6B cause I'm lazy, and can also be done here: http://indoavis.co.id/main/tas.html)
I should have a hypothetical TAS of approximately 238 Knots, or 440 km/h.

Now if we want to get really fancy we can use that to calculate both GS as well as wind correction.
The wind at Anapa is currently Northeast (I'll assume its from 45) at 5 m/s (~10 knots), and I've got no idea how we'd manage to get winds aloft data so we'll just use that.
I want to fly straight north on a heading of 0, and at my TS of 238 kts.
Technology has spoiled me (and also I don't remember the formula) so I'm gonna us the electronic E6B again, you can find it on the app store its called Sporty's E6B, I highly recommend it- just relearn the formulas before any checkrides lol.
(Can also do it here: https://e6bx.com/e6b/)
Anyhow the magic computer says my GS should be 231 knots, and my wind correction a positive 2 degrees.

All in all though, as far as IL 2 goes, I generally just go dead reckoning all over the place and worry more about getting blown out of the sky than I do about GS and all that fun stuff lol.
Also forgive me for any mistakes I might have made, its 2 AM and I'm procrastinating an essay.

[Skinny_Huesudo]

2 hours ago, Ram399 said:

Pressure altitude can be found using the field altitude, barometric pressure, and the temperature at ground level, all of which IL 2 luckily provides us.
Pressure altitude = (standard pressure - current pressure setting) x 1,000 + field elevation

I thought pressure altitude was simply putting the altimeter to 29.92/760 and reading the measurement

[Dakpilot]

6 hours ago, Ram399 said:

 

Technology has spoiled me (and also I don't remember the formula) so I'm gonna us the electronic E6B again, you can find it on the app store its called Sporty's E6B, I highly recommend it- just relearn the formulas before any checkrides

 

I am lazy,  and we are indeed spoiled by tech today, however your magic electronic E6B will go wrong or the battery's will go flat at the most inopportune time! 

 

I had a double GPS failure (we always had two mounted for redundancy) 

 

No prob the trusty (and tested) back up hand GPS is always in the flight bag... Which also failed

 

All this over Sudan during the civil war on the wrong side of the lines with isolated thunderstorms and fuel critical 

 

Not the best time to dig out the E6B, map and protractor. 

 

Anyway bit off topic, but if it can go wrong, it will! 

 

Anyway at least write down the pesky formulas somwhere handy ? ?

 

Cheers, Dakpilot 

[BlitzPig_EL]

Back when we were flying original IL2, one of the Pigs was involved in a mod group, and needed help verifying if temps were properly modeled.  So we all went up in He-111s, which had thermometers, on the Crimea map and climbed in formation and noted temp changes with altitude, and sure enough, that map was modeled with the standard lapse rate.

 

Have not done it in this version, but I'll bet that at least one of the maps is indeed modeled with the standard lapse rate.

[busdriver]

9 hours ago, Ram399 said:

All in all though, as far as IL 2 goes, I generally just go dead reckoning all over the place and worry more about getting blown out of the sky than I do about GS and all that fun stuff

 

You can't do any dead reckoning without having some sense of your ground speed. It is after all, flying a heading/track for a specific amount of time based upon a specific ground speed. Having a grasp of your ground speed can give you a better sense of how long it will take you to get to your mate that managed to trap 4 bandits on his six. 

 

I suspect you're simply using your pilotage skill set (map reading big features to small features). 

[Ram399]

8 hours ago, Dakpilot said:

All this over Sudan during the civil war on the wrong side of the lines with isolated thunderstorms and fuel critical

Wow that sounds like a hell of a story.
I've got the old cardboard E6B and a formula sheet buried in my flight bag waiting for their day to come lol

4 hours ago, busdriver said:

I suspect you're simply using your pilotage skill set (map reading big features to small features).

You are correct, I got the terms confused.

12 hours ago, Skinny_Huesudo said:

I thought pressure altitude was simply putting the altimeter to 29.92/760 and reading the measurement

Thats a the way of doing it in the plane, but as far as I'm aware there is no way in IL 2 to adjust your altimeter setting so I used the ground formula.
If there is a way to adjust that please let me know lol.