Each package (airplane) has a config and an air file, such as
Aircraft.cfg
Epic_LT.air
Then in the 'aircraft' config (above) in the 'Registry blocks' (blocks of info for each plane type you have of that particular aircraft, such as pure white, blue stripes, all red, etc), you have at the top of each block the number of each one. If you just have one plane right now (early prototype?) then you just have one registry block.
Here is a typical block from my Epic I made a while back;
[fltsim.0] <---- Number of the block, starting at zero
title=Epic LT Prototype <--- A Name for it
sim=Epic_LT <--- IMPORTANT; Air File Name; Folder Name; Sim Name
model=
panel=
sound=
texture=
kb_checklists=EPIC CHECKLIST.htm
kb_reference=
atc_id_color=0x00ffffff
atc_id=N77691 <--- N-Number for ATC
ui_manufacturer=Epic <---- Manufacturer
ui_type="Dynasty" <----Type
ui_variation="N77691" <--- Variant
atc_heavy=0
atc_id_font=Verdana,-11,1,600,0
visual_damage=0
description="blah blah tech-blah"
That should help you to iron out the base settings for your plane to show up.
Adjust all of your configs using Notepad, and you can use 'AirED.exe' (freeware) program from adjusting your Air files on planes, (like flaps, drag, etc).
Bill