Occurrences & Sequence Events data recoded in 2008

[michaelkotrous]

According to the NTSB data dictionary, cause factors were moved from the seq_of_events table to the findings table beginning in 2008. This explains the discontinuity in occurrence codes, phase of flight codes, etc. from Jan. 1, 2008 to present (see chart below)

It would be nice to integrate the finding table into the final dataset. Careful consideration will have to be made as to how the differences in the table structures will present themselves to analysis across the entire time series and conclusions that can be drawn.

[michaelkotrous]

The Events_Sequence table in the eADMS export includes occurrence and operation phase codes in six-digit compounds, starting with accidents in Jan. 2008. From the eADMS Data Dictionary:

With the implementation of eADMS in 2006, the "Events_Sequence" table will replace the "Occurrences" table and the "Findings" table will replace the "Seq_of_events" table.

The logical structure of these tables are different. Rather than the seq_of_events -> occurrences -> aircraft structure of pre-2008 accident records, these tables will be merged such that events_sequence -> aircraft and findings -> aircraft separately. The Events_Sequence table includes a field defining_ev, which according to the data dictionary means:

For each accident, one of the events cited in the events_sequence timeline is further identified as the "defining event". This is meant to group accidents of similar type, and is not meant to indicate or suggest cause.

Causes are identified the same way in the Findings table as they were in the seq_of_events table for pre-2008 accident records. Findings are numbered like sequence events, but it's not apparent that they are listed in chronological order. The findings table also offer detailed finding codes, the last two digits of which are a modifier code that can be used to interpret causes as related to "aircraft," "personnel issues," "organizational issues," or "environmental issues."