What was found
AIRCRAFT WAS GROUNDED: WHEN USING APU BLEED FOUL ODOR IS PRESENT DURING CRUISE AND ON THE GROUND . NO ODOR WITH ENGINE BLEEDS. MAINTENANCE FOUND THE R1 DOOR DRAIN FILLED WITH STAGNANT WATER AND POOLING IN THE BILGE AREA. MAINTENANCE CLEANED THE AREA AND DRAIN LINES PER AMM 38-32-00. (AALA202302140274) ALSO FOUND CABIN RECIRCULATION FILTERS DIRTY AND REPLACED THEM PER AMM 21-21-41. (AALA202302142728) NO ODORS WERE NOTED.