What happened
On July 20, 2004, a Christen A-1 aircraft, registration PH-KIS, was conducting an advertising tow flight departing from Rotterdam Airport. The mission involved flying over Nijmegen before returning to the airfield. The pilot's plan was to release the advertising banner at a low altitude near runway 24 and subsequently land on runway 06.
However, immediately after releasing the banner at an altitude of approximately 5 meters, the engine ceased operation due to a lack of fuel. The pilot was forced to perform an emergency landing in the grass near runway 24. The aircraft eventually came to a stop near the threshold of runway 06. The pilot remained uninjured, and while the aircraft sustained no significant damage, it required towing from the field.
The investigation
The investigation focused on the fuel levels and the pilot's management of the flight parameters. Post-flight refueling revealed that approximately 199 liters of fuel were added to the tanks, which actually exceeded the aircraft's maximum capacity of 197 liters. This confirmed that the engine failure was caused by fuel exhaustion.
The aircraft utilizes a high-wing design with fuel sight gauges visible from the cockpit. While this system is generally reliable, the investigation noted that accurate readings require the aircraft to maintain a level flight without slipping.
Prior to the flight, the pilot had checked the fuel levels, noting they were at approximately three-quarters capacity, which theoretically provided enough fuel for the planned three-hour mission. However, the investigation established that the pilot had flown at a higher power setting than usual during the outbound leg to save time, resulting in a much higher fuel consumption rate than the anticipated 35 liters per hour.
Findings
- The primary cause of the incident was inadequate flight planning regarding fuel consumption relative to the power setting used.
- Poor fuel management during the flight contributed to the exhaustion of the supply.
- The pilot's decision to fly at a higher power setting increased consumption beyond the calculated reserves.
- There was an over-reliance on fuel sight gauges and a lack of consideration for the increased burn rate during the outbound leg.