Did you change the actual aircraft before saving the missions?
In the FMB>
Once clicked on the object box at top needs to be opened so you can scroll through the list of planes in order to choose the one you want to replace the other plane with.Check plane one too make sure the "player's aircraft" box is checkmarked.Then save the mission by another name that you will remember.
That should work
Quick Mission Tuner is quick and easy to use
It is a Utility that can change aircraft in missions and much more>
http://www.mission4today.com/index.php? ... ls&id=3451
You can also open the .Mis file with notepad and edit the aircraft in the .mis file>
Missions/Single/DE/BF_109/BF_109_1.mis
find this mission and open in notepad
find this mission and open in notepad>
Missions/Single/DE/Me-163B-1/Me-163.mis
Now scroll down the BF_109_1.mis mission file and you will find that the first aircraft mentioned is the player aircraft(you are player 0).
The aircraft I highlighted in Red!
[MAIN]
MAP Kuban/load.ini
TIME 12.0
CloudType 3
CloudHeight 1500.0
player II_JG5_210
army 2
playerNum 0
[Wing]
II_JG5_210
g0112
g0111
8GvShAP10
11GvIAP10
[II_JG5_210]
Planes 2
Skill0 3
Skill1 2
Skill2 3
Skill3 3
Class air.BF_109G6
Fuel 100
weapons U3R6-MG151-20
Now look at the other mission file named Me-163.mis
look down for the first aircraft under player 0 and you will find>
Class air.ME_163B1A
simply cut the "Class air.BF_109G6" out of the BF_109_1.mis file and replace by copy and pasting the "Class air.ME_163B1A"
into the BF_109 mission file.
Also you must cut the weapon assignment out of the BF109 mission because the ME-163 does not come with U3R6-MG151-20
The last line I copied to here from the mission file up above has weapons U3R6-MG151-20(just below (fuel 100).
Just cut "weapons U3R6-MG151-20" out of the .mis file from there or you will get a weapon error on loading the .mis
Now save it and the BF_109_1.mis will now have you sitting in a ME_163B1A
This is all that QMT does,it edit's the mission file for you.
Notes: when switching aircraft,if they are set for take off whether from an airfield or ship...
they will lose the take off set point and they will airstart.You may even airstart at 500 ft alt. with power at 0 because the plane thinks it was taking off for some reason.In the FMB you can readjust the speed through the object box and by selecting the aircraft so as you can work on the parameters of it.
Easy