graphic showing various aspects of flight
Illustration from article

Greater emphasis on technical issues such as the airworthiness of aircraft and the integrity of the communication links may produce greater safety dividends as against a narrowing of focus onto human operator issues.

Civil RPAS is a rapidly growing market space, and is in no way limited to hobbyists flying radio controlled aircraft. This requires an understanding of risks associated with the industry (RPAS operations), such that safety can be improved.

Results show that, in contrast to commercial air transportation (CAT), RPAS events have a significantly different distribution when categorized by occurrence type, phase of flight, and safety issue.

It was found that all categories for RPAS were statistically significantly different for occurrence type, phase of flight, and safety issue in terms of the total number of events, and for accidents alone.

Specifically, it was found that RPAS operations are more likely to experience (1) loss of control in-flight, (2) events during takeoff and in cruise, and (3) equipment problems. It was shown that technology issues, not human factors, are the key contributor in RPAS events.

This is a significant finding, as it is contrary to the industry view which has held for the past quarter of a century that human factors are the key contributor (which is still the case for CAT). 

The phases of flight investigated in this work included: Takeoff (including climb out),En-route, or cruise,Approach (including descent),Landing.It should be noted that other typical phases of flight with considerable accidents/incidents events for CAT (standing and taxiing), were omitted from this study.

In an industry that has been conditioned to see human factors as the way to improve safety, reducing human factors risks can be an appealing and obvious solution.

Greater emphasis on technical issues such as the airworthiness of aircraft and the integrity of the communication links may produce greater safety dividends as against a narrowing of focus onto human operator issues.

Remember the Law of Instrument? To a man with a hammer, everything looks like a nail…
That’s the big takeaway here. The FAA and CAA’s around the world have long focused on pilot error. With no pilots aboard, other causes emerge. The recommendation is:

It is thus recommended that regulatory authorities continue to consider RPAS airworthiness requirements and other technical issues in addition to RPAS operator licensing when drafting new RPAS regulations, if not considering them first.

BTW despite the small sample (152 events) this is an extremely rigorous study.

download the paper at mdpi.com