The Report indicates that the Aviation Accident occurred south of runway 25, in front of the International Flights Terminal at Juan Santamaría Airport in Alajuela on April 7, 2022.

That day, the Crew communicated to the Control Tower that they were experiencing problems with the aircraft’s hydraulic system and that they would return to Coco.

The Final Report CR-ACC-CO-002-2022, issued by the Accident and Incident Unit of the Civil Aviation Technical Council (CETAC) and dated September 22, 2023, outlines some of the conclusions reached in the final report.

The accident involved a Boeing 757 aircraft with Panamanian registration HP-2010DAE, which had taken off from Juan Santamaría International Airport in Alajuela bound for Guatemala City.

The aircraft belonged to the company DHL Aero Expresso and experienced a failure in the hydraulic system along with an unexpected control lever movement.

The Guatemalan pilot noticed mechanical malfunctions resulting from hydraulic system problems and immediately requested authorization to return to Costa Rican territory.

At around 10:30 a.m. that day, after landing, the aircraft veered off the runway and broke in two, immediately prompting a major response at the air terminal from the Fire Department and Juan Santamaría Airport staff.

The 235-page document revealed that the acceleration of the left turbine was carried out outside the operator’s standard operating procedures for that specific moment of landing, which caused the runway excursion due to an inadvertent movement of the left power lever.

The report notes that these actions were documented by the Accident and Incident Unit (UAI) upon arriving at the scene, in a retracted position as a result of prior flow actions before the checklist known as the “Shutdown Procedure.”

Furthermore, it points out that the emergency was caused by excessive hydraulic system pressure, producing multiple fracture modes in wire strands, resulting in fatigue and ductile separation, cracks, and voids in individual cables in a cross-section of the retraction hose of the downlock actuator in the cross-section of the flexible hydraulic hose.

Alcohol tests conducted on the surviving pilots returned negative results.

Damage was also recorded to slopes and channels on nearby land covering approximately 605 square meters, as determined by the CETAC analysis.

Regarding environmental damage, hydrocarbon infiltration into the soil was detected at approximately 8.32 cubic meters, in the green areas between taxiway Alpha and the southern vehicular road over 800 square meters, and grass deterioration over 7,400 square meters.

The accident can be divided into two parts: one involving the hydraulic failure, and the other being the contributing factor to the accident.

The hydraulic system failure was due to fatigue and tension on the individual cables in the cross-section of the flexible hydraulic retraction hose of the downlock actuator on the L/H MLG, that is, the left side of the main landing gear.

On the other hand, the contributing factor to the accident itself was determined through the Cockpit Voice Recorder (CVR) and Flight Data Recorder (FDR): it was the inadvertent synchronized movement of the right Reverse Thrust Lever and the left Engine Control Thrust Lever, meaning left and right power, movements that were not consistent with the actions called for by the expanded checklist used in the standard procedures known as the “Landing Roll Procedure” and “After Landing Procedure,” the official explained.

He detailed that, in summary, the report found that in this case there was an acceleration movement of the power levers, the left one especially, in a flight phase where deceleration was required and that action was not appropriate. It was concluded that Human Error was ruled out.