you need add this to avionics ini
[HUD]
HUDMaterial=HUDMaterial
HUDColor=0.0,1.0,0.0,0.7
BoresightOffset=0.0,0.0
ViewportTopLeft=-0.130,-0.135
ViewportBottomRight=0.130,0.235
GunBoresightAngle=-2.5
RocketBoresightAngle=0
[HUDMaterial]
EffectShaderName=fltHUD.fx
DepthBufferCheck=FALSE
DepthBufferWrite=FALSE
RenderedInOrder=FALSE
AlphaTestEnabled=TRUE
CullMode=NO_CULL
LightEnabled=FALSE
UseLightLevel=FALSE
SpecularEnabled=FALSE
EmissiveEnabled=FALSE
FogEnabled=FALSE
AmbientColor=1.000000,1.000000,1.000000,1.000000
DiffuseColor=1.000000,1.000000,1.000000,1.000000
ZBufferOffset=0
PriorityLevel=1
BlendOp=BLEND_SRC_ALPHA
NumTextureStages=1
TextureStage[01].TextureName=
TextureStage[01].MipMap=FALSE
TextureStage[01].FilterEnabled=TRUE
TextureStage[01].StageColorOp=TEXTURE_MODULATE_DIFFUSE
TextureStage[01].StageAlphaOp=TEXTURE_MODULATE_DIFFUSE
taken from a Mig-27D