Why did we need a Drone TRA to fly at 170m?
In June of 2022, Drone Services Ireland was engaged by an International Client to perform an Aerial Survey of an Irish Cement site. Located at Platin, on the outskirts of Drogheda, it was well known to us. We had specific requirements from the client regarding resolution and accuracy.
As the chimney stacks are visible for many miles in the area, we decided we needed to conduct an on-site recce. The on-site survey was good practice as we knew the chimneys and cooler stacks were tall. Only when we flew the drone up the full height of the stack did we realise they topped out at 120m.
At this point, we knew we needed a different approach. Under our EASA Specific Category Operational Authorisation, we are permitted to fly above the tower but need to be within 50m of it. We engaged with the UAS Manager within the IAA and applied for a TRA. We needed to fly over the site constantly to maintain the required ground sampling distance. A smaller Mavic or Phantom drone was not going to cut it.
Working with the IAA, we applied for permission to fly at 170m AGL within 1 nautical mile of the plant, and Drone Services Ireland was granted the required authorisation. The airspace was closed off for the time of the survey. TRAs and NOTAMs notify manned and unmanned operators of the exceptional conditions for the drone survey, and the IAA published these on their website and through social media channels.
The DJI M300 RTK with P1 was flown at 170m with a flight termination system and parachute on-board. The 45MP images from the camera provided less than 2cm ground sampling distance (GSD), which was more than enough to meet the needs of the survey. Resulting in a pleased client and end-user, while demonstrating our ability to complete this work safely and efficiently, the safe approach, in this case, proved its worth.
