What was found
AFTER LEVELING OFF AT FL 260 & COMMENCING THE CRUISE PHASE OF FLIGHT, PAXS REPORTED A BURNING SMELL POSSIBLY COMING FROM THE VENTS IN THE CABIN. AT THE SAME TIME THE, RT BLEED FAIL, ANNUNCIATOR LIGHT ILLUMINATED. AN EMER LANDING WAS DECLARED & THE ACFT RETURNED WITHOUT INCIDENT. TROUBLE SHOT & FOUND A SEPARATED DUCT ON THE FLAPPER VLV ASSEMBLY UNDER CABIN FLOOR. THE HEAT FROM THE SEPARATED DUCT CAUSED THE BLEED SENSE LINE TO FAIL. SECURED THE SEPARATED DUCT & REPLACED THE BLEED AIR SENSE LINE. SYS OPERATIONAL CHECK WAS GOOD. ACFT WAS RETURNED TO SERVICE.