What was found
DURING WALK AROUND FOUND YELLOW HYD SERVICING PANEL MISSING. THE DISCREPANCY WAS DEFERRED VIA CDL 29-031. REPLACED THE YELLOW HYD SERVICING PANEL. SINCE THIS WAS THE SECOND EVENT ON THIS ACFT FOR THIS PANEL, AN ENGINEERING INVESTIGATION WAS CONDUCTED TO DETERMINE THE CAUSE OF THE PANEL LIBERATION. THE INVESTIGATION COULD NOT DEFINITIVELY CONCLUDE THE REASON FOR THE PANEL DEPARTURE. THERE WERE NO OTHER EVENTS ON THIS FLEET, NOR HAVE THERE BEEN ANY FURTHER ISSUES ON THIS ACFT. THE INVESTIGATION WAS CLOSED WITH NO ADDITIONAL ACTIONS NECESSARY.