Mpizpilot,
Sorry to hear about the crash.
I would take all of your radio gear including servos, switches, batteries, wire extensions and set this up on the ground and perform some range checks to see if you can determine a cause for the crash. I am surprised that you were getting HOLDS with a Tower Trainer, with no ignition, no carbon fiber or other RF shielding material. The 4.8V battery is within the RX requirements and there should not be very high current drains with a Tower Trainer, but see if you can check the voltage with the system on moving the servos. If you cannot determine the cause of the problem I would ship all of this equipment to Horizon to see if they can diagnose a problem.
I had something similar to me happen. Horizon found the problem to be a corroded fuse contact in the TX. I had been storing it outside in my shed, and I live in Houston
I store inside now
Keep us posted on what you find out.
Good luck,
Keven