What happened
The pilot was conducting an aerial advertising flight along the coastline at an altitude of approximately 800 feet. While operating the aircraft, he attempted to switch the fuel supply from the right tank to the left tank. Immediately following this action, the engine lost power. Unable to maintain altitude or reach a suitable landing site, the pilot was forced to ditch the aircraft in water that was approximately 14 feet deep.
The investigation
A post-accident inspection of the aircraft revealed significant discrepancies regarding the fuel system status. Investigators found that the left fuel tank was completely full of fuel, while the right fuel tank was entirely empty. This finding contradicted the pilot's implication that he was switching from a depleted source to a full one, or at least suggests a complex failure in fuel management or transfer mechanics.
To determine if external factors contributed to the loss of power, inspectors checked the fuel tank filler caps for signs of leakage. The inspection confirmed that no leakage was found on either cap, ruling out simple spillage or venting issues as the primary cause of the empty right tank.
Findings
The sequence of events points to a critical failure in fuel supply during the transition between tanks. The fact that the left tank remained full while the right was empty suggests that the engine may have been drawing from the right tank until it was dry, or that the switching mechanism failed to deliver fuel from the left tank despite it being full. The lack of leakage at the filler caps indicates that the fuel did not escape the system externally.
The pilot's decision to switch tanks during a low-altitude coastal flight appears to have been the immediate precursor to the engine failure. The shallow depth of the water (14 feet) likely facilitated the ditching but does not mitigate the mechanical or procedural error that led to the loss of power.