Sec. 1271.20. Aircraft to be started and run by qualified persons only

No aircraft engine shall be started or run at the air terminal unless a certificated pilot certificated to operate that particular type of aircraft or a certificated A and P mechanic qualified to start and run the engines of that particular type of aircraft shall be attending the controls. Wheel blocks equipped with ropes or other approved devices for blocking an aircraft shall always be placed at the front and rear of each main landing wheel and the brakes of the aircraft shall be on and locked before the engine or engines are started, except in cases where in the opinion of the manager, other proven procedures are equally safe.