The independent experts assigned by the judge investigating the crash of Spanair flight JK5022 on August 20, 2008, in which 154 people were killed, have concluded that human error on the part of mechanics was the primary cause but that Boeing and aviation authorities also contributed.

"The maintenance personnel did not identify the cause of the breakage and dispatched the aircraft incorrectly, turning to point 30.8 of the MEL [Minimum Equipment List manual]," the experts' conclusion read, adding that the document is written in such a way as to "induce error."

The aircraft, a Boeing MD-82, detected a fault in an exterior heat sensor and returned to the stand. A Spanair mechanic found that a heater, designed to prevent ice forming on the sensor, was active and, following the manual, disconnected it. A Civil Aviation Accident Investigation Commission report published in August 2009 noted that in addition to this fault, the pilots failed to carry out the proper checks prior to take-off, did not correctly deploy the wing flaps, and that the TOWS warning system also malfunctioned.

The MD-82 has a history of failures, including a crash in Detroit that killed 154 people in 1987 and one in Indonesia in 2005 that left 25 people dead.

The report also stated that the "history of accidents caused by the inadequate configuration for take-off had not been addressed, up to the date of the JK5022 accident, with sufficient corrective measures on the part of [Spanish and EU] aviation authorities or the manufacturer to solve the problem."