Perhaps the free to play portion of the game model can look something like this:
Option 1 Recommendation:
1. 1st 2 weeks, no changes. Allow full access.
2. AFTER the 2 week free trial (full version):
a. 3 weeks of free play in all Early War planes
b. At the end of the EW 3 week free trial, offer 1 final week in all planes sets.
Basically, 1 1/2 months. Gives time to learn enough to play and understand what you are doing. Get to know new players. Allow them access to special events and join FSO as a guest to a host squad. Basically giving more time to potentially new players to get a little past the learning curve.
Option 2 Recommendation:
Allow full access in the MA to all Early War Planes as a "free to play". But in doing this, you can potentially ruin the play in the arena. Not too difficult to troll the arena in this scenario. Maybe worth the risk though.
Not saying we should try any of this. Just throwing some ideas out for HTC to consider to generate traffic. Maybe already tried and didn't work. I dunno. I just fly cartoon planes and die a lot. THAT is my specialty.