UAS Safety Risk Portfolio and Analysis

UAS Safety Risk Portfolio and Analysis


The key risk areas of UAS operations have been identified by EASA through analysis of the reported occurrences in the ECCAIRS database involving UAS operation analysis.

Airborne Conflict

Airborne conflict in the context of UAS specifically covers the risk of airborne collision between a drone and an aircraft in the air. This key risk area accounts for Mid Air Collision/Airprox and Navigation occurrences as well as safety occurrences related to ATM/ANS. Further details about the key risk area are provided in Chapter 10 of the analysis.

Aircraft Upset

The second key risk identified by occurrence category analysis is Aircraft Upset, which covers the full range of Loss of Control situations. Whilst UAS upsets (Loss of Control) are different than those involving manned aircraft because there is no risk to persons on board the aircraft, there is a potential for injuries to people on the ground depending on the planning of the flight and the reversion modes of the UAS following a technical failure. Loss of control is particularly relevant for UAS as they are likely to operate in closer proximity to the ground than other types of air vehicles.

System Failures

Both System/Component Failure Powerplant and Non-Powerplant are potential outcome types and therefore would be included in the UAS key risk areas. For the purpose of the safety risk portfolio analysis these safety events are assigned to two areas. The first one is Engine Failure, which covers failures of the UAS propulsion system. The second one is Other System Failures, which includes both electrical and control systems as well as software and data link failures.

Third Party Conflict

The fifth key risk area covers the risk of UAS conflicts (collisions) with people or property (i.e. not involving aircraft) where they may cause injuries or damage. There were no occurrences involving such damage or injuries reported but scenario based risk assessment has identified this as a potential outcome that should be included as a key risk area for UAS operations. It is known that accidents involving UAS colliding with people on ground do happen, indeed such an event happened in the USA involving an UAS being used for media filming. However, none have been formally reported within the EASA member states. As the UAS industry is relatively new it could be possible that injuries due to drones are simply not reported on aviation level, but are only reported in hospitals where the injuries are treated or at local law enforcement level.

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