What happened
While performing powerline survey operations north of Sutton, New South and Wales, the pilot and observer aboard VH-DLA were navigating the electrical network distribution area. After completing two orbits east of Tallagandra Lane, the pilot turned north-north-east. Witnesses observed the Cessna 182 then execute a left turn toward the northwest, which transitioned into a steep descent and subsequent impact with the ground. The wreckage and witness accounts indicated the aircraft entered an aerodynamic spin before hitting the terrain.
The investigation
The ATSB examined the flight path and aircraft condition, finding that the pilot was appropriately qualified and rested for the demanding nature of powerline surveying. No mechanical defects were identified in the aircraft during the site or wreckage examination.
Investigators determined that the pilot likely attempted a direct turn toward a specific T-off powerline rather than using the partial orbit method recommended by the operator. This direct maneuver toward rising terrain likely increased the bank angle and wing load factor, which in turn raised the aircraft's stall speed. Data suggests the aircraft was operating at a low airspeed, possibly due to deceleration during maneuvering or an attempt to climb over terrain. As the aircraft banked, it likely exceeded the critical angle of attack, leading to a wing stall and a subsequent nose-down spin. At the moment the spin began, the aircraft was at an altitude lower than the manufacturer's minimum requirement for spin recovery.
Findings
- The pilot lost control of the aircraft while maneuvering to align with a powerline.
- The aircraft was at an insufficient height above the ground to allow for a successful recovery from the spin before impact.