Flight Testing in CoD

[TheGrunch]

We have ambient temperature gauges in the Ju 88 and He 111 if this helps. Likewise, if we can work out exactly the altitude at an airfield (FMB maybe?) and compare it to the altitude given by the aircraft's gauges we may be able to work out pressures.

[heloguy]

Originally Posted by Viper2000

I suggest that we use the 1976 standard for comparison purposes because this allows us to avoid some otherwise potentially nasty conversions (eg changes to Temperature scales over time...).

Obviously the next thing that we need to do is to find some way of measuring the atmosphere properties on a variety of available maps so that we can pick the best one for testing.

Does anybody have any suggestions as to how we might best go about this?

I would think that the 1976 standard day wouldn't be the best choice as that's not what testing data from the 30's and 40's was based on. Maybe the earlier two would be the best to use.

As far as ambient conditions, either use the gauges in game and hope they are calibrated correctly, or just e-mail the developers to find out what the stock standard atmospheric conditions are.

If there's a way to adjust atmospheric conditions in the FMB (I would look, but will not have my computer with COD for awhile as I'm in the States), then you could create a mission in the FMB that all testers would be compelled to use that are a part of this project.

Really, the best historical data (if it exists) would be that which has variable test data, such as a curve that represents the difference in performance compared to altitude and temperature on the graph axes in order to adjust for density altitude. If this sim has variable weather as it says, then it will be hard to see if the aircraft performs correctly over a range of temps and pressures if it's only tested on a standard day.

[Viper2000]

Originally Posted by Osprey

I don't know if this ever started or how serious Viper is but I am willing to help with the testing but ONLY if there is some assurance from the development team that it is being taken seriously.

From what I am seeing wider Europe is undertaking a Public Beta test which is adhoc and incredibly disorganised.

So, if we are given genuine co-operation from Luthier & friends, and that we supply genuine reliable information to them to use, then I'm signed up.

I haven't started any work on this yet because, as you point out, we're effectively in a public beta at the moment, and with major code changes taking place so regularly the chances are that a lot of the work we put in would be wasted.

I've also got a PhD to finish.

Originally Posted by heloguy

I would think that the 1976 standard day wouldn't be the best choice as that's not what testing data from the 30's and 40's was based on. Maybe the earlier two would be the best to use.

As far as ambient conditions, either use the gauges in game and hope they are calibrated correctly, or just e-mail the developers to find out what the stock standard atmospheric conditions are.

If there's a way to adjust atmospheric conditions in the FMB (I would look, but will not have my computer with COD for awhile as I'm in the States), then you could create a mission in the FMB that all testers would be compelled to use that are a part of this project.

Really, the best historical data (if it exists) would be that which has variable test data, such as a curve that represents the difference in performance compared to altitude and temperature on the graph axes in order to adjust for density altitude. If this sim has variable weather as it says, then it will be hard to see if the aircraft performs correctly over a range of temps and pressures if it's only tested on a standard day.

Using a 1930s or 1940s atmosphere standard is likely to cause confusion, because all sorts of things were different in those days (eg the definition of the Kelvin).

It's also inherently more likely to produce flame wars because if we pick a NACA atmosphere then people will see American aeroplanes with data which looks like primary source data and potentially German or British aeroplanes with corrected data which disagrees with primary sources. We would then find ourselves having to explain the concept of standard atmospheres and correction factors in the face of vociferous accusations of bias from the large population of trolls that inhabit the forum.

Whatever we do, we're going to end up picking a single standard atmosphere so that we can compare the performance of all the aeroplanes in the sim on the same chart. Apart from anything else, if we don't do this, the chances are the somebody else will do so in a biased way with the intention of forwarding their own agenda, since quite a lot of forum trolls seem more interested in being able to say "my aeroplane is better than yours" than in historical accuracy.

Ideally, I'd use the ISO standard atmosphere, because it's neutral and current. However, I don't think that it's freely available, and that would both interfere with testing and lead to accusations that the process was not transparent.

The 1976 US standard atmosphere is freely available on the internet, and avoids most of the risk of accusations of bias it's post-war*, and it is relatively modern (so we get basically modern SI units, though it uses its own private value of the gas constant, presumably for historical reasons).

*Therefore all of the aeroplanes we test will see correction factors.