*3.3. Level 1—Event Outcomes*

112 top-level event outcomes were coded with the MxFACS taxonomy. Figure 5 illustrates the top-level event outcomes. Once the initial outcome category for each event was identified, they were coded in further depth to better detail the nature of the event.

**Figure 5.** Level 1 top level event outcomes.

Trends within this data are in complement of the UK CAA's Significant Seven [21], and the Key Risk Areas (KRA) identified by EASA [4]. The KRA's present the outcome of accidents in the Safety Risk Portfolios published by EASA. Of the applicable top safety risks the UK CAA [21] present, three can be seen as of relevance from this study: runway overrun or excursion; airborne and post-crash fire; and loss of control (discussed further in Section 3.4). Whilst possible for maintenance actions to result in a runway incursion or ground collision, none of these types of events were identified within the study's time period.

Further exploring these Level 1 results alongside the five maintenance KRAs, runway excursion can be seen as the highest-ranking event outcomes in Figure 5. Terrain collision is fifth overall, and aircraft environment demonstrates some relevance within the study also.
