Reflecting on a UAS Incident: The Importance of Pre-flight Checks

In an effort to promote safety and shared learning, we examine a recent drone incident reported by the UK Air Accidents Investigation Branch (AAIB). The aim is not to apportion blame, but rather to glean valuable lessons that can contribute to improved flight safety standards for unmanned aircraft systems (UAS) operators globally.

In the incident under review, a drone was deployed in a police operation over an abandoned building near a public car park and train station.

Unexpectedly, during a hover over the building, the aircraft's motors ceased, causing it to drop vertically without prior warning. The drone struck the building's roof, resulting in the battery separating from the main frame.

Examination of recorded data suggested the battery most likely disconnected mid-flight, which could have stemmed from either the battery not being completely latched before takeoff, or a worn latching mechanism or battery causing an in-flight disconnection.

In response to the incident, the operator initiated safety action, reminding their pilots of the critical importance of pre-flight checks and assessing the airframe and battery condition before each mission.

Human Factors Analysis

Analysing the human factors involved in this incident brings the crucial aspect of thorough pre-flight checks to the fore. It underlines the potential consequences of operational complacency or overlooking routine procedures, such as ensuring the battery is properly secured before flight.

Battery connection issues might be easily dismissed as a minor detail, especially by seasoned operators. However, this incident shows that a battery disconnection, whether caused by a faulty latching mechanism or just not being fully latched prior to takeoff, can result in an abrupt loss of control and potential damage or injuries.

What we can glean from this incident is the need for constant vigilance and meticulous attention to every aspect of the pre-flight procedure, including seemingly minor elements like battery connection. It's a reminder to operators to double-check even the seemingly most mundane aspects of their equipment. It's these simple steps that can make all the difference in preventing accidents.

Overall, a careful approach to pre-flight checks, including ensuring that the battery is properly latched, could serve as an effective preventive measure. By maintaining a disciplined focus on these routine but crucial tasks, pilots can significantly reduce the likelihood of in-flight disconnections and associated incidents.