What happened
On February 5, 2010, a Raytheon B36TC, registration PH-HGG, was preparing for a flight from Den Helder Airport to Cranfield Airport, England. The aircraft was carrying a pilot and five passengers. During the takeoff roll on runway 22, the aircraft reached a rotation speed of approximately 75 to 80 knots and lifted off. Immediately after the landing gear was retracted, the pilot experienced severe instability. The airspeed dropped to 60 knots, triggering the stall warning. Despite full power being applied, the aircraft rolled uncontrollably, eventually striking the ground with its left wing, belly, and right wing. The aircraft slid approximately 100 meters through the grass before coming to a halt. The accident resulted in one injury among the occupants.
The investigation
The Dutch Safety Board (OVV) examined the aircraft's condition and the pilot's preparations. Investigators found that the aircraft's weight at takeoff was 4,409 lbs, which exceeded the maximum allowable takeoff weight of 3,866 lbs by approximately 14%. Furthermore, the investigation revealed that the aircraft was carrying approximately 73 US Gallons of fuel, significantly more than the pilot's estimate of 50 US Gallons. The investigation also noted that the center of gravity was positioned very close to the rear limit, a condition evidenced by witnesses observing the aircraft tilting backward significantly while taxiing. Technical inspections of the aircraft found no mechanical failures that could account for the loss of control.
Findings
- The aircraft was operating significantly above its maximum takeoff weight.
- A critical lack of weight and balance calculation meant the pilot was unaware of the actual loading conditions.
- The center of gravity was dangerously close to the aft limit, which, combined with the nose-up trim setting, contributed to a rapid loss of airspeed after takeoff.
- The margin for safe operation was extremely narrow, as the calculated stall speed was approximately 59 knots while the rotation speed was roughly 64 knots.
- The pilot relied on outdated information provided by a different pilot for flight planning, failing to verify the actual weight of passengers and fuel on the day of the flight.