What was found
AFTER TAKEOFF THE "FEEL DIFF PRESS" ILLUMINATED. NOTE: WHEN POWER WAS REDUCED TO RETURN TO THE AIRPORT THE LIGHT WENT OUT. PERFORMED FIM TASK 27-31-00-810-803 INITIAL EVALUATION, CONFIRMED INTERMITTENT FAULT. PERFORMED FAULT ISOLATION PROCEDURE III PER FIM 27-31 TASK 803, FOUND BOTH VISCO JET DRAINS CONTAMINATED. REMOVED AND REPLACED 2EA JET DRAINS PER SAME. PERFORMED ELEVATOR PITOT PROBE HEAT TEST IAW 30-31-00, NO DISCREPANCY FOUND. PERFORMED REPAIR CONFIRMATION IAW FIM 27-31 TASK 803, OPS & LEAK CHECK NORMAL. REF ATTACHED FORM 44.0008CM FOR FULL WORK DETAILS, OK TO CONTINUE.