Since the publication of the ATSB report A safety analysis of remotely piloted aircraft systems 2012 to 2016 (AR-2017-016) in March 2017, the ATSB has observed a significant change in the trend of reported occurrences involving Remotely Piloted Aircraft Systems (RPAS). Contrary to the previous report, our most current forecasts predict the total number of RPAS occurrences reported to the ATSB in 2017 to be comparable to 2016.
Due to this new information and the lack of data present in the public arena, the ATSB opted to publish a new edition of the report detailing our current understanding of the implications to transport safety associated of RPAS activity in Australia. Data presented in this edition is current to the end of June 2017.
Why the ATSB did this research
The growth in the number of remotely piloted aircraft systems (RPAS) in Australia is increasing rapidly. This presents an emerging and insufficiently understood transport safety risk.
The ATSB aims through this report to present data and analysis to further understanding of the implications for transport safety associated with the continual growth of RPAS activity in Australia.
What the ATSB found
Although accurate assessments of the number of RPAS in Australia is not possible, using proxy data, it is clear that the number of RPAS in Australia is growing rapidly each year. Compared to 2016, there will be a possible doubling in the number of systems in Australia by the end of 2017.
In association with the level of growth, the number of RPAS‑related safety occurrences reported to the ATSB increased rapidly during the 2012 to 2016 period. However, the first half of 2017 saw significantly fewer occurrences than predicted given the previous data. Current forecasts—incorporating data up to the end of June 2017—predict the number of RPAS occurrences reported to the ATSB in 2017 to be comparable to 2016.
Over half of all occurrences from January 2012 to June 2017 involved near encounters with manned aircraft, almost three‑quarters occurred between January 2016 and June 2017. Most occur in capital cities, Sydney in particular, and above 1,000 ft above mean sea level (AMSL).
To date, there have been no reported collisions between RPAS and manned aircraft in Australia.
The next most common type of occurrence involved collisions with terrain, almost half of which results from a loss of control of the RPAS.
The consequences of collisions between RPAS and manned aircraft are not yet fully understood. World-wide, there have been five known collisions. Three of these resulted in no damage beyond scratches. However, one collision with a sport bi-plane in the United States in 2010 resulted in a crushed wing. Fortunately, the aircraft landed safely. Less fortunately, a Grob G 109B motor glider had a wing broken by an RPAS collision in 1997 in Germany, resulting in fatal injury to the two people on board.
Due to the rarity of actual collisions, there is limited data from which to draw conclusions regarding the possible outcomes. Laboratory testing and mathematical models produced by various agencies have been used in conjunction with abundant aircraft birdstrike data in an attempt to assess the probable consequences of a collision.
RPAS collisions with high capacity air transport aircraft can be expected to lead to an engine ingestion in about eight per cent of strikes. The proportion of ingestions expected to cause engine damage and engine shutdown will be higher than for bird ingestion (20 per cent of ingestions).
RPAS have the potential to damage a general aviation aircraft’s flight surfaces (wings and tail), which could result in a loss of control. Furthermore, a collision with a general aviation aircraft’s windscreen poses a high risk of penetration.
A collision with a helicopter’s windscreen poses a similar penetration risk. Any impact on a helicopter’s tail rotor could cause catastrophic failure of the rotor.
Safety message
The operation of remotely piloted aircraft is an emerging risk to transport safety that requires close monitoring as the popularity of these aircraft continue to rapidly grow.