What happened
On 3 November 2013, a Pilatus Britten-Norman BN2B-21 Islander, registration G-CIAS, was engaged in a private search and rescue mission near the Channel Islands. The aircraft was tasked with locating two fishermen in difficulty near Les Écréhous. The flight was conducted under challenging conditions, including low cloud, poor visibility, and strong southerly winds.
Approximately six miles north of Jersey Airport, the right engine began to fluctuate in RPM, accompanied by fluctuating fuel pressure that went unnoticed by the pilot. The pilot attempted to use alternate intake air, but the engine subsequently stopped. Shortly after, the left engine's RPM also began to fluctuate before it ceased producing power. The pilot declared a MAYDAY and attempted to climb using the remaining power on the left engine, but the engine failed as well.
As the aircraft descended, the pilot prepared the crew for impact. The aircraft performed a forced landing on a relatively flat area of terrain. During the 140-metre ground roll, the left main landing gear collapsed, and the aircraft eventually came to a halt when the nose lodged in the base of a tree. There were no fatalities or injuries among the pilot or the four search crew members on board.
The investigation
Investigators examined the aircraft at the accident site and analyzed the fuel system configuration. They discovered that the fuel switches were set to draw from the tip tanks rather than the main tanks. While the main tanks contained sufficient fuel, the tip tanks were nearly empty.
Further investigation into the aircraft's history revealed that during a flight the previous day, the tip tanks had been selected for use. Because the aircraft was routinely refuelled after flights, the fuel consumed during the previous mission was replaced, but the fuel level in the tip tanks was not replenished to the required levels. The investigation also noted that the crew did not routinely use dipsticks to verify physical fuel quantities and that there was no practice of comparing predicted versus actual fuel consumption.
Findings
- The fuel supply to both engines was exhausted approximately 15 minutes after takeoff.
- The fuel system was left configured to draw from the tip tanks, which contained only a small amount of fuel remaining from the previous day's operations.
- The pilot did not notice the fluctuating fuel pressure in the right engine.
- There was a lack of routine physical fuel quantity verification and a lack of fuel consumption monitoring.