Level bombing in freezing weather

[Crious]

Hi generally i have perfect results in level bombing in TAW conditions.

E6BX helps a lot to establish a root to the target as well as to feed some of the bombardier settings before take off.

As well as weather temperatures are "normal" i am almost dead accurate. But in freezing weather conditions lofte7 doesnt work as accurate as it ... sould be.

You see my bombs land behind the target at temperatures les than -15 c.

In game we get 3 different altitude measurements. One from instrument panel one in bombardier position and a third if the "help" is on at the bar at the base of the screen. The problem is that all three of them are way different at hi altitudes when the weather is icy.

Even if i take into account the elevation of the target subtracting from what i see in the instruments bombs fell behind the target.

My only solution is to fire up a little or way more before croshair meet the target. Does the development  team has to suggest anything on the matter?

I have the feeling that instead of setting the altimeter to the nearest airfield elevation transmitter we should be able to set that according to barometer conditions.

Same goes for the bza in me 410 and arado 234 (in every weather condition this time).

Thanks in advance for any reply 

[AEthelraedUnraed]

6 hours ago, 335th_GRAlbatros74 said:

I have the feeling that instead of setting the altimeter to the nearest airfield elevation transmitter we should be able to set that according to barometer conditions.

Well, realistically pilots wouldn't have had the current barometer conditions at any other places than friendly areas - they'd have had forecasts at best. But anyhow, since the air pressure is static in game (it's constant across the map and across a single mission), IMO it doesn't really make sense to set it to anything else than the actual air pressure.

 

Since you use the E6B already anyhow, you may want to have a look at its front side (the two dials). I couldn't find it on E6BX, but here's a different site that does have it: https://mediafiles.aero.und.edu/aero.und.edu/aviation/trainers/e6b/. It has a dial for compensating altitude for the air temperature, although I'm not exactly sure how the complete conversion chain of indicated->true altitude goes.

[Crious]

3 hours ago, AEthelraedUnraed said:

Well, realistically pilots wouldn't have had the current barometer conditions at any other places than friendly areas - they'd have had forecasts at best. But anyhow, since the air pressure is static in game (it's constant across the map and across a single mission), IMO it doesn't really make sense to set it to anything else than the actual air pressure.

 

Since you use the E6B already anyhow, you may want to have a look at its front side (the two dials). I couldn't find it on E6BX, but here's a different site that does have it: https://mediafiles.aero.und.edu/aero.und.edu/aviation/trainers/e6b/. It has a dial for compensating altitude for the air temperature, although I'm not exactly sure how the complete conversion chain of indicated->true altitude goes.

Thanks for the site.

As far as the actual air pressure setting i am afraid that there is not such in the game. The only thing we get is setting our current airfield altitude to zero; but how accurate is the air pressure reading at the top of the altitude dial?

[AEthelraedUnraed]

7 hours ago, 335th_GRAlbatros74 said:

As far as the actual air pressure setting i am afraid that there is not such in the game. The only thing we get is setting our current airfield altitude to zero; but how accurate is the air pressure reading at the top of the altitude dial?

Actually, you can set the altitude to AMSL (actual pressure). On my PC, it's Alt-A, but I'm not 100% sure I never changed it so the default binding *might* be different (I don't think so though).

 

Anyhow, I think I understand the procedure now.

Let's first get our readings:

To the left is the indicated altitude above the nearest airfield, which is practically useless in this situation. In the middle is the indicated altitude AMSL, which is approximately 4370m. In the small window, we can see the pressure is around 1013mbar, which is standard atmosphere. This is great, since it means we don't have to convert to pressure altitude (if the pressure is different from standard atmosphere, use a pressure altitude calculator). Finally in the right dial, we can see the current air temperature is around -30C.

 

Next we take our E6B:

 

1. Let's first convert from metres into those pesky feet, which we'll need for our next step. Match the "METERS" arrow on the inner circle to the "FT" arrow on the outer one.
2. Just to the right of the arrows, we can see that 4375m is about 14400ft.
3. Now in the window on the left of the inner dial, match the altitude of 14400ft to the air temperature of -30C.
4. On the inner scale, find your current altitude of 4375m (in this step, it doesn't matter if you use feet or metres). Opposite on the outer scale, read the true altitude. In this case, it's around 4090m.

Our actual altitude as defined in the mission file was 4000m. So we're still a bit off, but at least we're now 285m closer to our actual altitude than what we started off at, a 4x improvement

Now where does the remaining 90m offset come from? I don't know. Note that the inner scale requires the Calibrated Altitude, and this differs from the Indicated Altitude because of instrument errors. However, a 100m difference does seem a bit excessive. So it might just as well be a bug or a deliberate simplification (i.e. they linearised the pressure-altitude-temperature relationship, since exponentials are notoriously expensive to calculate compared to a simple multiplication).

Edited December 30, 2024 by AEthelraedUnraed

[Crious]

Marvelous!!! Thanks a lot...

[AEthelraedUnraed]

18 hours ago, 335th_GRAlbatros74 said:

In game we get 3 different altitude measurements. One from instrument panel one in bombardier position and a third if the "help" is on at the bar at the base of the screen. The problem is that all three of them are way different at hi altitudes when the weather is icy.

I did some more testing. It seems that the instrument panel gives the uncalibrated indicated altitude AMSL (or above the nearest airfield level), the bombardier panel gives the true altitude AMSL, and the instrument panel gives the true altitude AGL.

 

In other words, when bombing, always use the bombardier altitude minus the target altitude. This should give you the proper settings to input in the altitude dial of the bombsight.

 

In my test flight, flying from an altitude of 6000m AMSL, 0 wind, -15C temperature at ground level and standard atmosphere, I was able to get within 10m of my target using the bombardier altimeter. Which is dead on accurate from that height.