What was found
THE DE-ICE ALCOHOL LOW LEVEL WARNING LIGHT ILLUMINATES ON THE MASTER WARNING PANEL AT AIRCRAFT ROTATION DURING TAKEOFF. ONCE ACTIVATED, THE LIGHT STAYS ILLUMINATED UNTIL POWER IS REMOVED FROM THE AIRCRAFT. LEARJET ISSUED OPTIONAL SERVICE BULLETIN 60-30-1 TO ADDRESS THE PROBLEM. SINCE THE ILLUMINATION OF A CAUTION LIGHT OCCURS AT SUCH A CRITICAL POINT IN THE FLIGHT, SUBMITTER'S OPINION IS THIS IS A SAFETY OF FLIGHT ISSUE. SUBMITTER RECOMMENDS THAT LEARJET RE-CLASSIFY THE BULLETIN TO MANDATORY, OR THE FAA SHOULD CONSIDER ISSUING AN AD.