The Air Accidents Investigation Branch has this week published their report on the video drone that came down during Henley Royal Regatta last year and hit and damaged the Celtic Queen boat stating that if the drone had struck a person it is likely it would have been fatal.
In the report it stated that the drone a “UAS, an Alta X, was being operated commercially to provide video footage at the Henley Royal Regatta when a low voltage battery warning occurred in flight at a height of 50m. As the aircraft was being flown back to the landing site, the aircraft battery voltage reduced to the point where controlled flight was lost. It fell, in near free fall, and impacted a boat on the river, causing damage. No persons were injured. The pilot could not recall checking the aircraft’s battery voltage prior to take-off, and the low voltage battery warning had been changed to trigger at a lower level than that recommended by the manufacturer.”
The number of races scheduled during the first few days of the Regatta had increased from previous years, with about 80 races per day starting at about 0830 and
finishing about 1830. The races were scheduled in blocks of five with each race starting five minutes apart, and a ten-minute gap between each block. The report went on to stay, “It was the intention of the pilot to be able to film at least every second race, which meant that the aircraft would be flown about every ten minutes, with the aircraft landed back onto the pontoon between each flight. The pilot had intended to replace the aircraft’s two batteries after every third flight with a fully charged set. This was based on his experience that the dynamic nature of the flying could more quickly deplete the aircraft’s batteries. The battery voltage level was displayed to the pilot on his flight controller. When fully charged, the batteries were at 50.4 V and the pilot had configured the aircraft and hand-held controller to provide a warning when the voltage reached 42 V.”
At 1120 hrs on 29 June, the aircraft took off on its 21st flight of the day, which was to film race 35. The flight initially proceeded as normal, with the pilot flying the aircraft overhead two competing. When the aircraft was about 250m up-river from the pontoon, the aircraft’s low voltage battery warning activated. The pilot responded by flying the aircraft back towards the pontoon to expedite its landing. However, when the aircraft was almost overhead the pontoon at a height of about 50 m, it stopped responding to the pilot’s commands and started to rotate whilst also descending rapidly. The aircraft struck The Celtic Queen, which was now almost abeam the pontoon, before falling into the river. No persons were injured. One of the aircraft’s batteries came to rest between the two passengers seated near the bow, which was about 2 m away from where the aircraft had struck the boat. The aircraft was not recovered from the river.
In the report it stated, “The pilot stated after the accident that he did not recall checking the aircraft’s battery voltage prior to taking off, and that his records indicated that it was making its sixth consecutive flight since the batteries had last been changed.”
The aircraft had initially collided with the forward left side cabin roof causing a dent to a section of the stainless-steel handrail and damage to the surface of the roof. The aircraft then struck the left side of the cabin and adjacent gunwale, prior to it falling into the river and sinking.
In the conclusion the report states, “Whilst returning to land following a trigger of the low battery voltage warning, the aircraft’s battery voltage depleted to the extent that controlled flight was no longer possible. The aircraft descended, in near free fall, and impacted an occupied private boat on the river. If the aircraft had struck a person on the boat, it is likely that fatal injuries would have occurred. The pilot did not replace the aircraft batteries when he had intended to, and a pre-flight check of their voltage before the accident flight was most likely not performed. In addition, the low voltage battery warning had been set to a level below that recommended by the manufacturer. Had the battery warning been set to the manufacturer’s recommended setting, the aircraft may have been landed safely under the pilot’s control.”
The owner of the Celtic Queen declined to comment about the accident.
A spokesperson for Henley Royal Regatta said, “Public safety is our utmost priority at Henley Royal Regatta, and we are carrying out an in-depth assessment of the AAIB report with our safety advisors. We are also evaluating all the recommendations and learnings from the pilot and our production partner Sunset + Vine before reaching a conclusion. No decision over the future use of the drone has yet been made.”
You can read the full AAIB report here There were two drone investigations with battery failure by the AAIB in January, other was in St Albans.