As unmanned aerial vehicle (UAV) technology evolves, applications for UAV use are rapidly expanding and evolving as well. These include opportunities here in the tree care industry.
Davey Resource Group (DRG) – a subsidiary of Davey Tree Expert Company, a 49-year TCIA member company based in Kent, Ohio – uses UAVs, more commonly referred to as drones, for an array of projects. The company recently secured from the Federal Aviation Administration (FAA) two waivers for Beyond Visual Line of Site (BVLOS) flights. We asked Davey about the implications of the waivers as well as the growing roles drones play in tree care.
Registration for airspace
As the popularity of drones grew in the early 2000s, Congress recognized the need for safety regulation. In 2008, Congress recommended the Department of Defense (DOD) and the FAA form a study committee to review concerns arising from the integration of small, unmanned aircraft systems (UAS) in the national airspace. The FAA implemented a mandatory registration system for hobbyists in December 2015. In the first 30 days, nearly 300,000 owners registered. There are more than 534,000 recreational drones registered today.
In 2016, the FAA enacted the Small Unmanned Aircraft Systems (sUAS) Regulations (Part 107), providing operational rules for commercial use of drones. It was a step toward fully integrating UAS into the nation’s airspace. In a statement on the FAA.gov website, then-U.S. Transportation Secretary Anthony Foxx said, “We are part of a new era in aviation, and the potential for unmanned aircraft will make it safer and easier to do certain jobs, gather information and deploy disaster relief. We look forward to working with the aviation community to support innovation, while maintaining our standards as the safest and most complex airspace in the world.” The Part 107 rule intends to minimize risks to other aircraft, people and property on the ground.
Part 107 operational waivers
The FAA recognized that some commercial UAS operations would be out of compliance with the new rules. As a result, they implemented a waiver-application system. Activities requiring waivers include operations over moving vehicles, operations at night and operations beyond visual line of site (BVLOS), among others. Commercial entities can request a waiver for most operational restrictions. The applicant must demonstrate that the proposed operation can be safely conducted under a waiver.
Davey Resource Group saw opportunities for several projects that were out of reach within the parameters of Part 107. They applied and recently received two waivers, explains Rachel Miller, Davey’s project manager and chief supervisor of UAS operations. Miller says the FAA only grants BVLOS waivers to those who meet a strict criterion involving the safety standards and track records of the pilots conducting the mission.
The waivers DRG received exempt drone pilots from the usual FAA requirement that pilots maintain visual line of sight at all times with any drone they are operating. This is generally a distance of less than one mile from the remote pilot in command (PIC), depending on the size of the drone. Additional safety precautions include an onboard detect-and-avoid (DAA) sensor to automatically avoid air traffic or large birds while in flight. Also, setting up a mission control station on site to monitor the drone during flight enables the drone to operate beyond the pilot’s line of sight and collect data safely and much more quickly than with standard methods.
To put the extent of this accomplishment into perspective, at the time this article was written in December 2022, there were more than 304,000 certified drone pilots, and just 304 flight waivers had been issued to approximately 200 companies. According to DRG staff, they are the only tree care company currently holding approved waivers.
Projects across the country
DRG utilizes its Part 107 waivers for several projects. The San Bernadino Mountains are a rugged mountain range in Southern California. They span a length of 60 miles and a width of 40 miles. Within that space, there is a two-mile section that can’t be captured with terrestrial LiDAR (light detection and ranging), and that doesn’t support the use of conventional aircraft.
“This two-mile section is on a mountainside. There is 1,000 feet of elevation change over one-quarter of a mile,” explains Miller. “There is no accessibility for the mobile vehicle LiDAR that we utilize for the remainder of the project. The most important consideration is the safety of the ground crew, and the drone is the solution here.”
In Sandusky, Ohio, DRG utilized drones to map and treat invasive species in Erie MetroParks. They developed a land-management plan with input from Erie MetroParks personnel. To gauge current site conditions and distributions of vegetative communities at the East Sandusky Bay Management, DRG performed a field-based vegetation survey throughout the summer of 2020. DRG GIS & Remote Sensing Services personnel also conducted a UAV flight over the properties and captured nearly 16,000 images. The flyover was conducted with a DJI Matrice 210 V2 drone, using a MicaSense Red-Edge MX camera and DJI X5S camera to collect imagery used for the site assessment.
In the Southwest, DRG has utilized drones with multispectral imagery to monitor and track the spread of pests and diseases, such as oak wilt. BVLOS waivers for these types of large projects along miles of utility pipelines and heavily forested parks allow for more data capture. Also, drone use is much safer in the harsh environments and difficult terrain where visibility is diminished from the ground.
In North Carolina, DRG will utilize a waiver for coastal-hazard-mitigation mapping and land-cover-change projects inland. Similar to parks and utilities, BVLOS waivers allow data capture along linear miles and large acreages of property to monitor changes and track the results of mitigation projects.
Benefits of technology
Drone technology adds to efficiency and cost savings, according to Davey staff. UAVs can be deployed rapidly and gather data quickly and safely. They can supplement ground inspections and can limit employee exposure to hazardous terrain and chemicals. The waivers increase the benefits. “The line-of-site requirement really limits how much we can accomplish in a day. The visual line of site, with a clear field, is generally less than a mile, depending on the terrain. So we have to set up and move our operations about every mile or so to keep an eye on the drone,” says Deborah E. Sheeler, GISP, DRG’s production manager geospatial & amp, software support services.
“The waivers have increased our capabilities tremendously,” says Sheeler. “We can cover up to 2,500 acres per day with the drone, but with BVLOS waivers, it takes us to the next level, with longer range and leveraging the extended flight time over other drones.”
Sheeler explains that most of the time allotted for any given project goes into safety. “There is a lot of preflight planning, notice to aircraft in the vicinity and coordination with local airports and property owners. Then we program the drone to cover the target area. The majority of our time and energy focuses on preflight planning.”
DRG employs a fleet of drones for a variety of applications, including aerial herbicide spraying and seeding operations (Part 137, Dispensing Chemicals and Agricultural Products with UAS). However, for BVLOS missions, they use the Censys Sentaero, a drone designed specifically for BVLOS use. “Operating beyond visual line of site requires a detect-and-avoid system, so we use the Censys Sentaero BVLOS along with a mobile command station (MCC) with internal monitors and an extendable mast that is used for command-and-control linking and uninterrupted video streaming in a wide variety of environments,” says Miller.
Miller further explains that they may use a visual observer (VO) depending on the terrain or population density. “The VO helps with situational awareness, to keep an eye on the drone, avoid flying over people and scanning the area for any conflicting air traffic.” The company’s versatile fleet includes Skydio drones, which also have been approved for FAA-approved BVLOS flights for utility-asset inspections in the industry.
“We also use a variety of sensors and processing software, depending on the job,” Miller notes. DRG also uses a range of sensors for zoom-in capabilities, as well as LiDAR, multispectral and thermal imaging. The vast array of software for data, imagery and LiDAR processing is available for a variety of projects.
Training and career path
Davey Resource Group trains staff to operate the equipment with multi-week virtual and in-person training for BVLOS drone-operator certification. “On top of that, they learn about using high-level cameras and processing the images,” says Sheeler. “They learn about the spread of pests and diseases, and applications for vegetation and invasive-species management.
“It’s definitely part of a great career path,” she says. “It works well for tree care professionals to learn drone skills, because they know what they are looking at. We are not just bringing drone pilots in; they already have in-house experience and gain drone knowledge. They also already have a high level of safety and risk mitigation in mind,” she explains.
DRG plans to expand its drone program with a blanket waiver across the country. “As long as it fits with the criteria of the waiver, we can then complete a project without obtaining a site-specific waiver. Our goal is to have this in place by the end of 2023. The waivers bring us additional opportunities,” says Sheeler. “There are different solutions for different projects, and we are excited about all the possibilities.”