Final answer:
FAR Part 135 contains information on on-demand air taxi operations, setting forth certification, maintenance, and operational standards for such flights.
Step-by-step explanation:
The Federal Aviation Regulations (FARs) are rules prescribed by the Federal Aviation Administration (FAA) governing all aviation activities in the United States. The FAR that contains information pertaining to on-demand air taxi operations is FAR Part 135. This part addresses operating requirements for commuter and on-demand operations and rules governing persons on board such aircraft. It sets forth standards relating to certification, maintenance, and operational rules for on-demand flight operations, which typically comprise smaller, non-scheduled commercial flights such as air taxis, air tours, and charter services.