What was found
DURING FLIGHT, PASSENGER ATTEMPTED TO OPEN SLIDING WINDOW. WINDOW CAME OUT AND DEPARTED AIRCRAFT. NOT KNOWN IF WINDOW BROKE BEFORE OR IF SLIDE TRACK WAS FORCED LOOSE. MAINTENANCE REPLACED WINDOW ASSEMBLY DUE TO TOP SLIDE TRACK BEING UNBONDED. REF: 206L-1 IPB, FIGURE 52-2, ITEMS 21 AND 23.