Improving the Quality of Accident Investigation


Dane M. Mellan, Mason Ruffing, Victor Y. Zeng


National Transportation Safety Board


Constance Clark, David DiBiasio, Natalie A. Mello


October – December 2009

Project Outcomes

Final Report


The NTSB Office of Marine Safety (OMS) conducts accident investigations to prevent the reoccurrence of accidents. We compared the OMS and other agencies’ investigations through interviews of experienced investigators and analyses of accident investigation reports. We found inconsistency in definitions and methods used for causal analysis amongst OMS investigators resulted in an increase of report production time. We made recommendations to adopt the IMO causal factors definition as probable cause definition in conjunction with E&CF analysis to improve the quality of OMS’ investigations by increasing focus on safety issues.