Using DCG 3.48 (not a beta, the last) in dogfight mode.

The files I refer to below are in a 3rd Party Campaigns folder.

From my own Italy.mis campaign master:

[9AF_036FG_23FS00]
  Planes 4
  Skill 1
  Class air.P_51D20NA
  Fuel 100
  weapons default
[9AF_036FG_23FS00_Way]
  NORMFLY 50000.00 66200.00 500.00 300.00 &0
  NORMFLY 51000.00 66200.00 500.00 300.00 &0
[9AF_036FG_23FS10]
  Planes 4
  Skill 1
  Class air.P_51D20NA
  Fuel 100
  weapons default
[9AF_036FG_23FS10_Way]
  NORMFLY 50000.00 66000.00 500.00 300.00 &0
  NORMFLY 51000.00 66000.00 500.00 300.00 &0
[9AF_036FG_23FS20]
  Planes 4
  Skill 1
  Class air.P_51D20NA
  Fuel 100
  weapons default
[9AF_036FG_23FS20_Way]
  NORMFLY 50000.00 65800.00 500.00 300.00 &0
  NORMFLY 51000.00 65800.00 500.00 300.00 &0
[9AF_036FG_23FS30]
  Planes 4
  Skill 1
  Class air.P_51D20NA
  Fuel 100
  weapons default
[9AF_036FG_23FS30_Way]
  NORMFLY 50000.99 65600.99 500.00 300.00 &0
  NORMFLY 51000.00 65600.00 500.00 300.00 &0

From my own class.dcg:

P_40M_NEW                      Kittyhawk Mk.III                    gb 1 1 1 194303 194406 P_39Q10                        P-40M_NEW                           none                           3000 Meters 380.00 kph  Default     380.00 kph  
P_47D10                        P-47D10 Thunderbolt                 us 1 1 1 194306 194401 P_47D22                        P-47D-10                            none                           3000 Meters 480.00 kph  Default     480.00 kph  
P_47D22                        P-47D22 Thunderbolt                 us 1 1 1 194309 194410 P_47D                          P-47D-22                            P_47D10                        3000 Meters 480.00 kph  Default     480.00 kph  
P_47D27                        P-47D27 Thunderbolt                 us 1 4 1 194403 194612 none                           P-47D-27                            none                           3000 Meters 480.00 kph  Default     480.00 kph  
P_47D                          P-47D Late                          us 1 1 1 194409 194612 none                           P-47D                               P_47D27                        3000 Meters 480.00 kph  Default     480.00 kph  
P_51B                          P-51B-NA Mustang                    us 1 1 1 194311 194406 P_51C                          P-51B-NA                            none                           3000 Meters 460.00 kph  Default     460.00 kph  
P_51C                          P-51C-NT Mustang                    us 1 1 1 194401 194406 P_51D5NT                       P-51C-NT                            none                           3000 Meters 480.00 kph  Default     480.00 kph  
P_51CM                         Mustang Mk.III                      gb 1 1 1 194401 194412 none                           MustangIII                          none                           3000 Meters 480.00 kph  Default     480.00 kph  
P_51D20NA                      P-51D-20NA Mustang                  us 1 1 1 194405 194612 none                           P-51D-20NA                          P_51D5NT                       3000 Meters 480.00 kph  Default     480.00 kph  
P_51D5NT                       P-51D-5NT Mustang                   us 1 1 1 194403 194612 P_51D20NA                      P-51D-5NT                           P_40M_NEW                      3000 Meters 480.00 kph  Default     480.00 kph  

I customized the default altitude, but this isn't the matter.
I updated the Kittyhawk Mk.III (P-40M) datas from a single .mis file:

[Wing]
  usa0100
[usa0100]
  Planes 4
  Skill 1
  Class air.P_40M_NEW
  Fuel 100
  weapons default
[usa0100_Way]
  NORMFLY 75384.62 55384.62 500.00 300.00 &0
  NORMFLY 105256.41 55512.82 500.00 300.00 &0

So, now in my class.dcg file, Class air is: P_40M_NEW and the skin folder is P-40M_NEW.

It's the beginning of the campaign (28/07/1943) and the AircraftDowngrades=True in the dcg.ini file.
I can't get P-51D-20NA Mustang (194405).
I can't get P-51D-5NT Mustang (194403).

So I expect Kittyhawk Mk.III but I get the P-47D10 Thunderbolt.

Am I wrong somewhere or is there a bug?
 

Attached file: my class.dcg file

 

class.zip

What type of campaign are you generating?  A manual generation starts with a hard coded plane type so unless you're generating an "auto" with the appropriate DGen-based data files, you'll never get the Kittyhawk to appear from the start.

I'm in dogfight mode.

When a misssion end IL2SC run Exec=F:\IL2DCG\il2dcg.exe using the Parameter=netdogfight

Here's my dcg.ini:

 

F:\IL2DCG\
F:\IL2DCG\Aosta_DE\
F:\Ciel_de_Guerre_Serveur\
One
Two
Two
Two
Dense
Full
Sparse
Average
300 Kilometers
Default
Default
MassedBombers=False
FrontMovement=True
CopyMission=True
Dogfight=True
Coop=False
Not Used
AutoGeneration=False
Primary=False
DSTimes=True
Paras=False
Briefing=True
ShipRoF=20.0
HistDates=True
ThirdPartyServer=IL2SC
LogFileDate=[Apr 16, 2016 9:59:58 PM]
Tracking=True
NoTransfers=False
Night=False
DGEN_Replacement=False
TankDG=True
TransitAlt=Default
TgtEgressAlt=Transit Altitude
TgtAlt=Transit Altitude
TgtIngressAlt=Transit Altitude
IPAlt=Transit Altitude
TgtIngressOffset=Default
IPOffset=Default
TOStepAltBox=Default
NormandyBase=False
Death=True
AirStarts=False
TOCircle=All Types
IECoordinates=All Types Use
CruiseSpeed=Default
Language=English
GameID=1946
NGEN_Replacement=False
SingleMap=True
PalmTrees=False
RuSupplyRate=1/Squadron/Day
DeSupplyRate=1/Squadron/Day
TrackPlayerRanks=False
AircraftDowngrades=True
LinkMax=True
DataFiles=F:\IL2DCG\CDG_Italy_Online\
DeShipSkill=Rookie
RuShipSkill=Rookie
ShipSunk=False
ActiveFront=False
DDRoF=20.0
BridgeRepairTime=Random
BornPlaceRadius=2000
TimePassage=Normal
ServerInfo=On ground, external view allowed for easier taxing.
ServerActive=True
Balance=Balanced
SCPlaneLimits=No
SCTimeLimits=No Time Limit
SquadronManagement=False
IngressSpeed=Default
FixedStartDates=True
CountStaticPlanes=Yes
VoteLevel=100
Radio=Campaign Default
RandomNoseArt=True
NoUserLoadout=False
BeachheadResets=True
MDS=True
RUProp=No
StaticPlanes=No Spawn
NativeRuProp=False
DSMinutes=Default
 

Can you select the Kittyhawk through the Squadron Panel Editor on DCG after you've generated the campaign?  If not, there's something wrong with your class file.  If it's there, I'm not sure why it's not working.

I'll try it and let you know.