2012 Nuevo León Learjet 25 crash

Investigation

The investigation into the accident was carried out by the Mexican Directorate General of Civil Aeronautics (DGAC). Since the United States was the state of manufacture and registry of the aircraft, the US National Transportation Safety Board (NTSB) sent an accredited representative to assist with the inquiry.

In December 2014, the DGAC issued its final accident report. The investigation was hampered by the fact that the flight data recorder was destroyed in the impact, and no information could be retrieved. The cockpit voice recorder was never found.

From the analysis of the recorded radar information, it was determined that the Learjet had experienced a sudden loss of control while climbing through 28000 ft, leading to a nearly vertical high-speed nosedive. The angle of impact with terrain was estimated at 89°, and the impact speed higher than the aircraft's maximum operating speed.

Other flight crews that had previously flown on N345MC had reported occurrences of anomalous vibrations felt on the control column during cruise, leading the investigators to speculate that the sudden nosedive might have been the result of a failure in the horizontal stabilizer, although no hard evidence was found among the badly damaged parts of the system recovered from the wreckage.

Furthermore, the NTSB, after conducting laboratory analysis on the stabilizer's actuator, found no evidence of pre-existing damage or failure, and later issued a comment on the DGAC's findings that there was "no factual data that supports [the hypothesis of a horizontal stabilizer failure]."

The report concluded that the probable cause of the accident was "loss of control of the aircraft for undetermined reasons." It was also established that the flight crew was in breach of local regulations regarding age limits and qualifications. The captain, 78, had exceeded the maximum age allowed for his role, while the co-pilot, 21, did not hold a valid type rating for the Learjet 25.