What happened
The accident occurred during the initial climb phase of flight following takeoff from a grass runway that had not been maintained for several weeks. The airfield elevation was recorded at 1070 feet above mean sea level. Meteorological conditions were favorable, with calm winds and a temperature of 62 degrees Fahrenheit alongside a dew point of 50 degrees.
The pilot elected to use a full flap configuration of 20 degrees for the departure. This decision deviated from standard operating procedures, which typically recommend only 5 to 10 degrees of flap extension for restricted category aircraft equipped with dispersal equipment. The gross weight of the airplane was estimated to exceed the maximum allowable limit by approximately 291 pounds.
After achieving lift-off, the pilot reported that the aircraft began to settle rather than climb. As the plane approached the end of the available runway surface, the pilot dumped the onboard load in an attempt to reduce weight. Despite this action, the aircraft continued its descent and struck a ditch located approximately 50 yards beyond the runway threshold.
The investigation
Investigators examined the physical evidence at the crash site and reviewed the operational parameters of the flight. Key findings included:
- The runway condition: The grass surface had not been mowed for several weeks, potentially increasing drag during takeoff roll.
- Weight status: The aircraft was gross weight over the maximum limit by 291 pounds.
- Configuration error: Full flaps were used instead of the recommended 5 to 10 degrees for this specific aircraft category and equipment loadout.
Findings
The primary factors contributing to the accident were the excessive gross weight and the improper flap configuration. The combination of being over the maximum weight limit and using full flaps resulted in insufficient climb performance. The pilot's decision to dump the load after lift-off was too late to prevent the collision with the ditch.
Safety message
Pilots operating restricted category aircraft must strictly adhere to recommended flap settings for takeoff, especially when carrying external loads or dispersal equipment. Additionally, ensuring the aircraft is within its maximum gross weight limits is critical for achieving adequate climb gradients during departure.