Close Call Data Sources Review and Analysis

Kennedy Space Center - Close Call Data Sources Review and Analysis

Kennedy Space Center (KSC) is a launch facility where the United States space program launches the Space Shuttle, and numerous other missions. The Space Shuttle is an extremely highly engineered device, representing billions of dollars of investment. Extreme attention is paid to both safety and reliability.

Like many other aerospace operations, KSC collects voluminous data on problems, incidents, and close calls. These data are maintained in multiple databases, including PRACA (Problem Reports and Corrective Actions). The strategic intent is that these data can be used to improve operational safety and reliability.


Within safety engineering there is an assumption of a statistical relationship between close calls, incidents, minor accidents, and major accidents. This assumption is based on the "Heinrich pyramid" whose author, H. W. Heinrich, stated that based on this statistical relationship personnel could reduce the number of accidents by reducing the number of close calls and incidents.

More recent research suggests that in an organizational context, personnel may be motivated to disguise the occurrence of close calls, and whenever possible to hide incidents, in order to avoid blame for events that have complex causal chains.

The project objective is to determine if the PRACA databases contained patterns of data that could be extracted through "data mining" to identify problem situations before they developed into incidents and accidents.

The research team used a linguistic analysis and found that the PRACA database contained numerous occurrences of modal language ("might", "could", "ought"). These suggest that the personnel filing problem reports were concerned with the future ramifications of problems. These findings warrant an investigation of the statistical correlation between problem reports using modal language, and future performance of the subsystems described in the problem reports.

Project Personnel: Allen W. Batteau, Ben Mejabi, Willem Homan (Western Michigan University), Frances Trix, Carolyn E. Psenka, Margaret Karadjoff, Alex Perez

Project Sponsors: Kennedy Space Center, National Aeronautic and Space Administration