Runway drift and muscle memory

On April 7, 2022, a DHL Boeing 757-27A freighter departed Juan Santamaría Airport (Costa Rica) bound for La Aurora Airport (Guatemala) carrying cargo. Only the captain and first officer were on board. Earlier that year, the aircraft had already experienced two incidents - an emergency landing in Mexico City on February 11, 2022, without flaps, and another in San José on March 26, 2022, due to a loss of cockpit pressurization.

The takeoff was uneventful at 09:34 local time. However, at 5,800 meters (19,000 ft) and 56 km from the airport, the crew reported hydraulic problems. The display showed an L HYDRAULIC PRESSURE LOW warning. Shortly afterward, flight controls began to degrade.
At 10:00, the captain declared an emergency:

"Juliet-Oscar-Sierra seven two one six, Mayday, Mayday, Mayday. We have problems with the left hydraulic system. Two persons on board. Fuel endurance two hours thirty minutes. Holding at 13,000 feet. We are carrying a cargo containing a corrosive liquid. Preparing the aircraft for an emergency landing due to left hydraulic system failure."

The aircraft entered a holding pattern over the Pacific coast, about 40 km from the airport. Meanwhile, ATC cleared the approach path and positioned emergency services along the runway - a precaution that would prove necessary. Due to the hydraulic failure, the landing had to be performed without autobrakes and without reverse thrust on the left engine. Nosewheel steering and spoiler deployment were also limited.

During landing, the aircraft began veering uncontrollably to the right, then suddenly spun 180 degrees, veered off the runway, and plunged into a ditch in front of the airport fire station, breaking into two sections near the tail. The touchdown and "drift" were captured on video.
There was no explosion or fire, as the fuel tanks remained intact. The cargo did not contain hazardous materials. Both pilots escaped serious injury but were taken to the hospital for observation due to stress.

Following the emergency, Juan Santamaría Airport was closed for five hours. Several inbound flights were diverted to alternate airports. International flights to Costa Rica were rerouted to Guanacaste Airport in Liberia, forcing passengers to travel five hours by ground to reach the capital.

The investigation determined that the hydraulic fluid loss was caused by multiple fatigue cracks in the flexible hose of the actuator cylinder for the left main landing gear strut.

The sudden runway excursion after an initially normal rollout was traced to unexpected thrust from the left engine. Flight data showed that, during braking, the right engine correctly exited reverse thrust, but the left thrust lever unexpectedly and abruptly advanced forward to 92% power.

During interviews, neither pilot could explain the thrust lever movement. No technical faults were found that could have caused it. Investigators concluded that the most likely cause was an unintentional action by the captain - an experienced 58-year-old pilot with 16,000 flight hours. Over the years, he had developed strong procedural habits, a phenomenon known as muscle memory, which may have led him to instinctively push the left thrust lever forward without conscious awareness.