What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
The root cause of this incident resulting in an aircraft route deviation (with no loss of separation) was the flightcrew's inability to identify and to fly the revised high altitude jet airway routing that became effective on the date of this incident. The flightcrew referred to a current, but incorrect navigation chart produced by jeppessen and provided by the company as primary for navigation. This charting error combined with the aircraft's flight management system (FMS) deferral did not provide the flightcrew an opportunity to accurately identify the redefined jet airway and subsequently navigate along the cleared route. If the FMS had been usable on the date of the incident, the valid electronic database would have provided the flightcrew with the correct airway routing and subsequently allowed the crew to navigate along the redefined jet airway. Furthermore, eventhough the flightcrew followed stated procedures pertaining to MEL provisions for this deferral, MEL provisions as currently written are inadequate to prevent recurrence of a similar incident. Therefore, the company is currently evaluating both dispatch system / MEL provisions for risk identification and mitigation.
As the FAA filed it
THE ROOT CAUSE OF THIS INCIDENT RESULTING IN AN AIRCRAFT ROUTE DEVIATION (WITH NO LOSS OF SEPARATION) WAS THE FLIGHTCREW'S INABILITY TO IDENTIFY AND TO FLY THE REVISED HIGH ALTITUDE JET AIRWAY ROUTING THAT BECAME EFFECTIVE ON THE DATE OF THIS INCIDENT. THE FLIGHTCREW REFERRED TO A CURRENT, BUT INCORRECT NAVIGATION CHART PRODUCED BY JEPPESSEN AND PROVIDED BY THE COMPANY AS PRIMARY FOR NAVIGATION.THIS CHARTING ERROR COMBINED WITH THE AIRCRAFT'S FLIGHT MANAGEMENT SYSTEM (FMS) DEFERRAL DID NOT PROVIDE THE FLIGHTCREW AN OPPORTUNITY TO ACCURATELY IDENTIFY THE REDEFINED JET AIRWAY AND SUBSEQUENTLY NAVIGATE ALONG THE CLEARED ROUTE. IF THE FMS HAD BEEN USABLE ON THE DATE OF THE INCIDENT, THE VALID ELECTRONIC DATABASE WOULD HAVE PROVIDED THE FLIGHTCREW WITH THE CORRECT AIRWAY ROUTING AND SUBSEQUENTLY ALLOWED THE CREW TO NAVIGATE ALONG THE REDEFINED JET AIRWAY. FURTHERMORE, EVENTHOUGH THE FLIGHTCREW FOLLOWED STATED PROCEDURES PERTAINING TO MEL PROVISIONS FOR THIS DEFERRAL, MEL PROVISIONS AS CURRENTLY WRITTEN ARE INADEQUATE TO PREVENT RECURRENCE OF A SIMILAR INCIDENT. THEREFORE, THE COMPANY IS CURRENTLY EVALUATING BOTH DISPATCH SYSTEM / MEL PROVISIONS FOR RISK IDENTIFICATION AND MITIGATION.