Flight Testing in CoD

[TUCKIE_JG52]

Viper, that's a really nice effort, seriously focused... some time ago I was discussing in other forums about real charts of the planes, that were not corrected to the same atmosfere models...

I fly a Cessna 152 and from my early stages of training, I can see the big influence that ambient contitions have in performances like climb rate.

As ambient conditions I mean specially pressure and temperature. For example, before each takeoff I check the forecast for exact data and I get the exact calculation for the Pressure Altitude. If the pressure altitude of my airfield is below the real altitude of the field, that day the Cessna climbs a lot. It's the most common case in winter, with temperatures below ISA (15º) and sometimes pressures over ISA (1013Mb).

The inverse case is a higher pressure altitude when ambient is very hot and low pressures are registered... to the point that if pressure altitude is a lot higher than real altitude of the airfield, it can be a factor that can lead to an accident.

I see that your initial point of view takes this into account, so I'll follow your results with very interest.

I would collaborate with you if I were not so busy with video editing...

[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.

[TheGrunch]

The biggest problem really at the moment is the lack of a DeviceLink style interface yet and the inaccuracy of the rollover text on cockpit gauges (seems to be 1 decimal place, not very useful when altitudes are measure in km for example). Although I haven't even looked at the no-cockpit view so that might be better.

[TUCKIE_JG52]

Any data on this subject?

I've been focusing in Bf-109E-3 tests.

By landing beside a beach and setting the altimeter to 0, the indicated pressure in all maps is 993 mbar.

Ambient temperature is about 17ºC, but I must confirm with Ju-88 and He-111 instruments.



I've also looking for which are the german standards, named "Normaltag" ("Normal Day"):
I'm not sure about the data they considerred standard, but it looks like 1018mbar and 16ºC.

In this test there's a correction factor developed, but I can't undestarnd what every value really means:
http://www.kurfurst.org/Performance_...5a.html#blatt5

If that correction factor is correct, it would mean that with the current pressure and temperature settings for all maps in CoD, we'll never be able to reach the german values of the performance charts like climbing. Even more if it's considered that, as commented in this post, Bf-109 has an overloading problem:
http://forum.1cpublishing.eu/showthread.php?t=20160

Overloaded E-3 + not so favorable meteorological contitions = our graphs will look always under the german values.

We need to apply correction factors to really evaluate if CoD E-3's performances are correct or not.

[Viper2000]

Originally Posted by TUCKIE_JG52

Overloaded E-3 + not so favorable meteorological contitions = our graphs will look always under the german values.

We need to apply correction factors to really evaluate if CoD E-3's performances are correct or not.

Exactly.

I think that we should probably correct all of our performance references to ISO standard atmosphere conditions to produce an overall aircraft performance database, and then convert performance data from that database to whatever the conditions on our chosen test map are.

BTW, formation flying is the most obvious way to overcome the 1 d.p. limitations of the cockpit instruments, at least to some degree...

[Sternjaeger II]

definitely a good effort, but let me just say one thing..

we need to know exactly what parametres are needed in order to provide usable data and not waste any time. It would be worth to try and talk to Luthier about this, so maybe we could be directed in the right way..

Viper has a factual approach to things that is quite the right way to go, but before you jump in this head first try and seek for some support from the guys at Maddox Games.

[Vengeanze]

I don't understand anything you guys are saying here but I make darn good coffee!

[TUCKIE_JG52]

Originally Posted by Viper2000

Exactly.

I think that we should probably correct all of our performance references to ISO standard atmosphere conditions to produce an overall aircraft performance database, and then convert performance data from that database to whatever the conditions on our chosen test map are.

BTW, formation flying is the most obvious way to overcome the 1 d.p. limitations of the cockpit instruments, at least to some degree...

That was my idea too...



Yesterday I did pressure and temperature measurements. And got some conclusions that must be cross-checked.

Pressure measuring method:
1. Place a Ju-88 in a beach (Sea Level).
2. Set altimeter to 0.
3. Read pressure in milibars directly from the Kollsman window, in the upper side of the german altimeter.

Temperature measuring method:
1. Place a Ju-88 where you want to test the plane.
2. Read outisde temperature indicator

Facts found:

A) I get different values of pressure and temperature in the same place every time I reload the mission. Sometimes they'll repeat, but they tend to change more when a different plane is loaded in the same place. ---> Temperature and pressure are not always the same, there's some grade of randomisation. (This must be confirmed).

B) Ambient temperature is different from water and oil temperature before starting engine.


Clues to test:
-There's the possibility to switch from the cockpit of one plane to another, at least altimeters can be cross cheched in that way; same mission load, planes placed together on a beach, check if all altimeters have the same pressure reading in Kollsman when altimeter set to 0. --> If same readings oK, reload the mission to test randomisation of parameters.