What was found
AT 10000 FT STRAIGHT AND LEVEL FLIGHT, WITH NO POWER SETTING CHANGE. A BRIEF ODOR OF BURNING IN THE FLIGHT DECK ONLY. COMPLIED WITH TS 002737. COMPLIED WITH FIM TASK 21-21-00-810-806. R & R RECIRCULATION FAN NR 1 IAW AMM 21-22-10. OPS AND LEAK CHECKED SATISFACTORY. NO BURNING ODOR OR DEFECTS NOTED AT THIS TIME. PRIOR TO R & R, RAN ENGINES WITH QUALIFIED TECH YZ 96395 & NO ISSUES WERE NOTED.