Initial Findings From Spanish Investigators Indicate Need For Safety Improvements

Almost exactly a year ago, a Boeing (formerly McDonnell Douglas) DC-9-82 (MD-82), operating as Spanair flight JK5022, crashed after takeoff from runway 36L at Madrid Barajas International Airport, Madrid, Spain. Of the 172 people onboard, 154 died, including the 6 crewmembers; 18 passengers were seriously injured. The flight was destined for Las Palmas de Gran Canaria Airport in the Canary Islands. The airplane impacted a field between the departure ends of runways 36L and 36R and was destroyed by impact forces and postcrash fire. The investigation is ongoing, but initial findings have identified the need for safety improvements.

An interim accident report by the Comisión de Investigación de Accidentes e Incidentes de Aviación Civil (CIAIAC) of Spain indicates that the leading edge slats and trailing edge flaps were not extended during takeoff. This reduced the airplane’s ability to achieve adequate aerodynamic lift. The report also indicates that no takeoff warning system (TOWS) annunciations were recorded by the cockpit voice recorder (CVR) during the takeoff roll. According to the airplane manufacturer, the TOWS should have annunciated a clear and audible aural warning when the throttles were advanced to takeoff power while the trailing edge flaps were not extended in a takeoff position. The TOWS apparently had been disabled due to another problem with the aircraft.

The NTSB determined that the probable cause of the accident was the flight crew’s failure to use the taxi checklist to ensure that the flaps and slats were extended for takeoff. Contributing to the accident was the absence of electrical power to the airplane’s TOWS, which, thus, did not warn the flight crew that the airplane was not configured properly for takeoff. The reason for the absence of electrical power could not be determined. The NTSB now recommends that the FAA require that operators of Boeing DC-9 series, MD-80 series, MD-90 series, and B-717 airplanes include items in their preflight checklists to verify that a check of the takeoff warning system is accomplished before every flight.

Other recommendations from NTSB concerning this incident include:

• Modifying 14 Code of Federal Regulations Part 25 to include a certification standard that will ensure either that 1) the takeoff warning system (TOWS) cannot be disabled by a single failure or 2) if the system fails or has power removed while the airplane is operating on the ground, a discrete and clear annunciation of the loss of TOWS protection is provided to flight crews.
• Assessing the history of pilot errors related to takeoff configuration and identify needed mitigating design elements; require inclusion of such design elements when determining current and future aircraft certifications.
• Convening a meeting of industry, research, and government authorities, including international representatives, to develop guidance on industry best practices in operational areas (including checklist design, training, and procedures) that relate to flight crews properly configuring airplanes for takeoff and landing.
• Requiring operators to modify their takeoff and landing checklists to reflect the best practices identified as a result of the meeting recommended in Safety Recommendation A-09-70.

FMI: http://ntsb.gov/recs/letters/2009/A09_67_71.pdf