What was found
DURING CRUISE LT FUEL PRESSURE LIGHT ILLUMINATED. LT FUEL FLOW GAUGE ERRATIC. TURNING ON LT STNDBY PUMP HAD NO EFFECT ON FUEL FLOW. LT ENG BEGAN SPOOLING DOWN ON IT'S OWN. SECURED ENG IAW CHKLST. NO EXTERNAL ABNORMALITIES, LEAKS, SMOKE, FUMES, OR FLAMES NOTED. CONDUCTED SINGLE ENG LANDING WITHOUT INCIDENT. OUT OF CAUTION, DECLARED EMERGENCY, CONTACTED AK COMMS CENTER ON SATPHONE TO INFORM THEM OF SITUATION. PERFORMED DETAILED INSPECTION OF LT WING & NACELLE FUEL TANKS, FUEL VENTING SYS, FUEL FILTERS, & LT ENGINE FUEL SYS. FOUND LT WING OTBD AFT FUEL VENT CHK VALVE INTERNAL SPRING MISSING. PERFORMED MULTIPLE GROUND RUNS & OPS CHECK FLTS WITH NO DEFECTS OR ANOMALIES NOTED.