Chan was a male Human, born in the 2140s, who served in Earth Starfleet, and then in the Federation Starfleet. He was a veteran of the Earth-Romulan War, and skilled in starship combat.
By the 2250s, Chan held the rank of Rear Admiral, and at age 110, was an instructor at Starfleet Academy. During this time, Chan toured the Academy bridge simulator after it had been rigged by Cadets James T. Kirk and Gary Mitchell to simulate combat maneuvers during docking procedures. Chan, given his experience, was able to respond to the simulated emergency, and did not press for an investigation into the program tampering. (TOS novel: Prime Directive)