What happened
On 30 March 2016, a CESSNA 172R, registration EC-JSM, was conducting a visual flight from Sabadell airport to Cuatro Vientos airport. While flying over the town of Perales de Tajuña in Madrid, the aircraft's left wing strut collided with a griffon vulture. The force of the impact was so severe that the left wing detached from the fuselage.
Following the structural failure, the aircraft immediately lost control and impacted the ground seconds later. The crash resulted in 3 fatalities, including the pilot and two passengers. The aircraft was completely destroyed upon impact.
The investigation
The CIAIAC investigation focused on the mechanics of the collision and the structural integrity of the aircraft. Investigators analyzed the kinetic energy of the impact, noting that the aircraft was traveling at a ground speed of 100 knots. This resulted in an impact energy exceeding 8,323 joules, which significantly surpassed the certification requirements for aircraft in this category, which are typically only required to withstand much lower energy levels.
Technical analysis of the wreckage confirmed that the collision severed the wing strut. The investigation also reviewed the manufacturer's specifications, which noted that the Cessna 172 wing is attached to the fuselage via bolts at the front and rear spars, with the strut providing essential load-bearing support. Without the strut, the wing cannot remain attached to the fuselage under flight loads.
Findings
- The pilot held a valid private pilot license and medical certificate.
- The aircraft was airworthy and all documentation was in order.
- Weather conditions were clear and not limiting to visual flight.
- The accident site was not identified as a known breeding colony on official bird activity charts.
- The left wing detached because the impact with the vulture caused the wing strut to break.
- Current certification standards for this aircraft type do not require the wing or strut to withstand bird strikes of this magnitude.