It was a busy day at the airport. A B777 had just landed and stopped short of the stand to be towed in; as it waited, an arriving aircraft taxiing behind it scraped its left winglet against the B777 plane's tail.
The aircraft was being positioned onto the stand under tow following a risk assessment that concluded the risk of collision was greater for it to be parked under its own power for the particular stand. However, the change in procedure to mitigate the risk of collision introduced new hazards that had not been fully captured during a management of change exercise.
Risk mitigation typically includes using processes and procedures that, if not assessed carefully, might introduce new hazards and related safety risks associated with implementing any mitigation strategy. On top of that, these procedures and processes usually need to be run by humans. Therefore, human performance variability should also be considered when implementing risk mitigation. This can be referred to as “the risk of mitigations” or “risk transfer.”
Investigations focus on the allocation of front-line responsibility. It induces organizations to trigger interventions such as:
Reactively introducing new or changed procedures would make sense, but when done reactively and with a rush, there is more chance of unintended consequences; introducing new procedures makes operations more complex, increasing the gap between work as written and work as done. This might reduce human performance and increase human error.
Safety incident investigations, although it is a reactive approach, are still a valuable tool to drive effective risk management, particularly when, from the investigation process, the main conclusion highlights the need for enhanced operator Management of change processes and Risk assessment tools for operational changes with cross-functional impact.
