What happened
Approximately one hour and five minutes into the flight, the pilot noticed that the aircraft's fuel supply was depleting at an unusually rapid rate. In response to this critical situation, he initiated a precautionary landing sequence. The aircraft touched down on a gravel pit that contained shallow water. Following the impact with the water surface, the left pontoon separated from the main structure of the aircraft.
The investigation
A thorough examination of the aircraft was conducted to determine the root cause of the fuel loss and subsequent emergency landing. Investigators discovered that the fuel cap on the right wing was not properly secured prior to flight. Additionally, distinct fuel stains were observed aft of the fuel tank, confirming a leak from that specific location.
Findings
The rapid depletion of fuel was directly linked to the unsecured right wing fuel cap. This mechanical oversight led to significant fuel loss during flight, necessitating an emergency landing. The impact with the shallow water in the gravel pit caused structural damage, specifically the separation of the left pontoon.
Safety message
Pilots must ensure all fuel caps are securely fastened before flight to prevent fuel leaks and potential exhaustion.