build instructions trex 500 Uh-1B - new lightweight t-rex 500 combo new motor and comply with related UH-1B T-Rex 500 notes of instruction postal: unit d1-2, 6/f , por mee factory building. Trex 450 sport super combo (promotional sale) align-heli we ve changed uh 1 t rex 500 build simply replace part with rc heli.