What was found
DURING ANNUAL OPERATIONAL CHECK OF THE AFT LEFT ENTRY DOOR ESCAPE SLIDE, THE SLIDE DEPLOYED NORMALLY BUT THE SLIDE MOUNTED EMERGENCY LIGHTS FAILED TO ILLUMINATE. SLIDE OPERATIONAL CHECK FAILED. MAINTENANCE FOUND THE POWER UNIT ASSEMBLY FOR THE ESCAPE SLIDE MOUNTED LIGHTS HAD FAILED. MAINTENANCE REMOVED AND REPLACED THE AFT LEFT ENTRY DOOR ESCAPE SLIDE ASSEMBLY. TWO ADDITIONAL OPERATIONAL CHECKS ARE SCHEDULED TO BE CONDUCTED AT THE AFT LEFT ENTRY DOOR POSITION PER US AIRWAYS POLICY AND PROCEDURES.