What happened
On 15 December 2006, a PIPER PA-34-220T Seneca III, registration EC-HOL, was performing a private VFR flight from Fuentemilanos to Jerez Airport. While on final approach to runway 02, the aircraft's left engine suddenly stopped. The crew did not declare an emergency or report any technical difficulties to the control tower. Shortly after being cleared to land, the aircraft experienced a sudden loss of control, entering a steep, descending spin that lasted approximately one and a half turns. The aircraft impacted the ground approximately 1,25 and meters south of the runway threshold. The impact resulted in three fatalities and one serious injury.
The investigation
The investigation focused on the engine failure, the aircraft's flight characteristics, and the crew's response. Examination of the wreckage revealed that the left engine was inoperative and the propeller had not been feathered at the time of impact. The right engine was still producing high power. Investigators found that the aircraft was in a landing configuration with the gear down and flaps at 10 degrees.
Technical inspections of the left engine and propeller governor found no mechanical defects that would explain the sudden stoppage. Furthermore, the investigation noted that the aircraft's center of gravity was likely toward the rear limit because the two passengers were seated in the rear row rather than the recommended center row. The investigation also identified that the emergency checklists found on board were for a different variant of the aircraft, and the Pilot's Operating Handbook (POH) was not present in the cockpit.
Findings
- The primary cause of the accident was a loss of control resulting in a stall and spin at a low altitude while the aircraft was on the approach glide slope with an engine inoperative.
- The left engine stopped during the approach, but the reason for this failure could not be determined.
- The pilot in command had limited experience with this specific aircraft type (only 15 hours).
- The aircraft was likely operating with a rearward center of gravity due to improper passenger seating.
- The crew's lack of coordination and potential lack of familiarity with correct emergency procedures for this engine failure contributed to the loss of control.
- The presence of unfeathered, windmilling propellers increased drag and exacerbated the asymmetric thrust, making the aircraft difficult to control at low speeds.