It's probably a couple of months work to get make a new aircraft from scratch to good (but not great), and most people are dedicated to their own projects.
If you have ever considered learning 3D modelling and some simple programming you could start yourself. Even without too much help from people on the forum you will probably be able to make a flyable aircraft with a usable (but probably sparse) cockpit.
There is some documentation in places on the wiki and in the forum threads and even in your FlightGear installation itself, so you could poke around a bit and see if it would be something for you.