As one of the largest utility companies in the United States, Pacific Gas and Electric Company (PG&E) is also one of the largest customers for helicopters. Responsible for a service area encompassing almost half of the state of California, PG&E routinely contracts for around 30,000 helicopter flight hours per year, supporting missions including power line maintenance, construction, and patrols.
As Vertical recently reported, PG&E has no plans to reduce its reliance on helicopters anytime soon. Yet, over the past several years, the utility has been steadily ramping up its drone operations in parallel, logging more than 300,000 pole and tower inspections by uncrewed aerial system (UAS) in 2024.
Drones are not a direct substitute for helicopters, but they are highly complementary. Equipped with high-definition cameras, they can reveal details on structures that would otherwise only be visible through potentially risky, time-consuming climbing inspections. They can be used to string power lines in congested areas, helping to minimize disturbances to residents compared to using helicopters. And PG&E continues to find new uses for them.
“Helicopters will never go away, just because of the sheer volume of our territory and the rugged terrain that we operate in and the fact that our infrastructure is laid across the whole state,” said Chris Courtney, director of PG&E’s Aviation Services department. “But on the UAS side, the use cases keep going up exponentially.”
Closer inspections
PG&E’s ambitious drone inspection program represents a confluence of technology and incentives. The company performed its first drone inspections back in 2015. However, it didn’t commit to scaling the program until after the devastating Camp Fire in November 2018, which killed 84 people and cost PG&E around $25 billion in settlement payments.
The Camp Fire was caused by the failure of a worn suspension hook on a transmission tower. The investigation into the fire found, among other things, that this type of hardware may not have been reliably inspected by either helicopter or ground inspections.
Clearly, more detailed inspections of some towers were needed. At the same time, camera drones were becoming more sophisticated and capable, enabling their operators to capture high-definition imagery that could later be examined closely by experts.
Kellen Kirk, a former U.S. Navy aircraft mechanic and commercially rated airplane pilot, helped ramp up PG&E’s drone inspection program starting in 2019. Today, he works under the umbrella of the Aviation Services department as the manager of UAS and fixed-wing operations.
“When we first started the program, we were doing about 60,000 towers [annually], primarily focused on the transmission and substation,” Kirk recalled. “And that has expanded year after year.” Today, he said, it is typical to have around 80 UAS pilots out in the field every day collecting data.
Beyond growing the total number of drone inspections, PG&E has expanded the program from the transmission network — which carries high-voltage electricity over long distances — to also encompass the distribution network, which feeds lower-voltage power into homes and businesses. And, while the company still relies heavily on contractors to perform these inspections, it has brought a portion of them in-house under supervisor Daniel Toothman.
“Coming from the line department, and seeing what this can do for us, it’s game-changing,” Toothman said. “We want to lead the industry, this is the way that we have to go, and this company is all in — they’ve gotten us the best equipment, pilots, and training for our pilots.”
Safety first
PG&E and its contractors use a variety of drone types, although the majority of the drones it currently uses for inspections are made by DJI. In accordance with the Federal Aviation Administration’s (FAA’s) part 107 Small UAS Rule, all drone operators are required to hold a remote pilot certificate, and PG&E imposes additional training and qualification requirements depending on what missions the operator is performing.
“What we’ve done to be able to manage their training requirements is create certifications,” said program manager Bounmy Daoheuang, who is responsible for learning and development within the Aviation Services department. Daoheuang said that remote pilots are required to complete initial and recurrent web-based training modules on a variety of technical and safety topics, which are periodically updated to reflect any changes to procedures and learnings from the field, always with safety top of mind.
“I appreciate how this organization is more proactive than reactive,” Daoheuang said, noting that the Aviation Services department is constantly looking for ways to prevent incidents and accidents before they happen. Aircraft maintenance is part of this proactive approach: just like PG&E’s crewed aircraft, its drones are on a regular maintenance program designed by aircraft maintenance supervisor Dennis Doyle.
Although uncrewed aircraft do not carry the risk of harm to occupants that crewed airplanes and helicopters do, drone operations pose their own safety challenges. UAS operations are often “remote” in more ways than one, with drone operators routinely required to trek off the beaten path.
“The flying is the easiest part,” said Toothman. “There’s just so much more: there’s the driving; the slips, trips and falls; the hiking, dehydration, exhaustion.” He noted that PG&E’s remote pilots are provided with Garmin inReach satellite communication devices to help ensure a timely response in the event of an emergency.
Irate customers can also pose a safety risk, as many inspections are performed near homes and on customer property. “Customer contacts are extremely common for us, especially when we’re flying an asset on people’s property,” explained remote pilot Daniel Lira. “It’s standard operating procedure for us to knock and introduce ourselves.”
Lira said that most of these interactions are positive, and customer contacts are actually one of his favorite parts of the job. However, homeowners are occasionally combative, and some drones performing inspections for PG&E have even been shot out of the sky. All such incidents are tracked by the company’s in-house communications center, Flight Core, which provides weather briefings and flight clearances to any UAS, helicopter, or airplane pilot working for PG&E. If a Flight Core dispatcher sees that a pilot will be working in proximity to a known hostile customer, they will advise them to avoid making contact and involve corporate security as needed.
Going remote
Although PG&E’s drone inspections have been highly effective, the standard line-of-sight inspection process is still very manual and time-consuming, with productivity constrained by the time it takes UAS pilots to travel to and from their far-flung inspection sites. That is a primary reason why PG&E is now exploring more autonomous operations using dock remote technology from California-based drone manufacturer Skydio.
A dock is a combined hangar and charging station that allows a drone to be positioned at a critical infrastructure site but commanded from hundreds or thousands of miles away — in this case, from PG&E’s aviation facility in Concord, California. Using LTE signals or Starlink satellite internet for connectivity, the drones can be piloted manually in real time, and they can also fly pre-programmed missions autonomously.
“The advantage is just the ability to be able to respond to a situation instantly,” said dock remote operations UAS operator Tapiwa Piloto, who provided Vertical with a live demonstration of the technology. “Let’s say something happens up in Redding at our substation, instead of having somebody drive four hours up there to fly the assets, we can respond immediately.”
PG&E has received support for its dock remote operations program through the California Public Utilities Commission’s Electric Program Investment Charge (EPIC) program, which invests in scientific and technological research to accelerate transformation of the state’s electricity sector. PG&E was an early adopter of Skydio’s dock technology through the manufacturer’s early access program, initially using Skydio’s X2 drone. The companies are now in the process of transitioning the program to the upgraded X10 drone, which has improved sensors and autonomy.
According to program manager Jon Teach, who is overseeing the implementation of dock remote operations, PG&E currently has seven docks in operation, from Redding south past Paso Robles and into the Sierra Nevada Mountains. The drones are being used for regular inspections of infrastructure including power substations and penstocks, which are pipes used in hydro-electric dams to transfer water from an intake structure to a hydro turbine.
“The one mission that’s caused the most interest, I would say, is the penstock mission, because those penstocks are in very remote locations, and they’re going up a hill, and some of these hills are very, very steep,” Teach said. “So we have the ability to launch and then fly these missions without incident and very safely, without somebody having to go up there and walk.”
PG&E conducts its dock remote operations beyond visual line of sight (BVLOS) under a waiver from the FAA, and the permissions afforded by the waiver have been progressively expanded as the company has demonstrated its ability to operate safely. Although the technology is still being developed, Teach said he expects these operations to become more important in the future, with the “holy grail” being rapid response to fault detection.
“Somewhere there is a fault detected; one of our alarm systems, which is linked to our docks, will show an alert; we’ll be able to launch an aircraft immediately and get eyes on in a matter of minutes, which before could take hours — that’s what we’re working toward,” he said. “To be able to perform that task, there’s a large amount of different systems — our GIS [geographic information system], our alarm systems, the dock system — all coming together and being able to notify the pilot properly of where to go, and the aircraft being able to execute that with all the information that’s being gathered.”
Choosing the right tools
Thanks to the pace of innovation in the drone space, PG&E is continually expanding its existing applications for drones and finding new ones, with a special projects team led by Joshua Hill tasked with developing new use cases.
“In the five years that I’ve been doing this type of work, the technology has just exploded,” said Lira. “Drones are more reliable; the cameras are better. A drone will fly longer, you can get closer to an asset and take better quality data, and with more and more use cases, new drones are being brought in for the task.”
One such specialized solution is Infravision’s TX System, which includes a drone that can pull the rope used for stringing power lines — a task typically performed by helicopters. Pete Anderson, PG&E’s senior manager of helicopter operations, recalled a recent rope-pulling job near Vallejo where seven spans passed through a metropolitan neighborhood.
Rather than evacuate thousands of people in order to perform the work with a helicopter, a UAS team “came in, flew those seven spans with that drone and got the rope in. And then soon as it got to the end of that, the helicopter just picked back up and kept pulling. So it’s really finding that balance of the right tool for the right job,” he said.
Teach said that one of the things he finds so rewarding about working with drones is that because the technology is so new, there’s a continuous process of discovery and improvement, akin to the earliest days of airplanes and helicopters.
“This is new technology, and I don’t think that anybody really knows where the ceiling is, because once the sensors improve, once the range improves, we’re going to develop more use cases that we don’t even know exist right now,” he said. “And it’s just going to keep expanding.”
Going the Distance
Most commercial drone operations in the United States to date have involved aircraft weighing 55 pounds (25 kilograms) or less, the weight limit for the FAA’s part 107 Small UAS rule. While there are paths to flying larger uncrewed aircraft, it will likely be some time before heavy drones can operate in the national airspace system routinely.
In the meantime, PG&E uses contract helicopters for many of its power line patrols and its own two Cessna Caravans for gas pipeline patrols, which are the longest patrol missions it flies. “We patrol all of our pipelines, from the Arizona border to the Oregon border, quarterly,” said Kellen Kirk, manager of UAS and fixed-wing operations, pointing out that it would be wildly impractical to conduct these flights with drones that can only fly a few miles at a time.
The primary purpose of the patrols is to look for encroachments on underground pipelines — such as construction or agricultural work — by people who are unaware of the potential for conflict. The Caravans are equipped with Wescam MX-15 cameras that operators in the back can use to clearly see details on the ground from altitudes of 10,000 feet or higher.
“They have a precise GPS overlay so they can see where the pipe is underground while we’re flying,” explained fixed-wing supervisor Ben Doyle. If they see a potential threat, “they’re able to, in real time, contact the ground and send someone out there to make sure that they’ve done an underground survey and that they’re aware of where the pipeline is, or if they’re not to have work be stopped until that safety measure can be put in place.”
The Caravans also conduct survey missions using onboard lidar, which is used for purposes including general mapping, vegetation management, and detecting movements in the earth. They additionally provide emergency response support and move people and equipment on an as-needed basis. Combined, the two planes currently fly around 700 hours per year.
PG&E maintains the Caravans in house with heavy maintenance support provided by Textron Aviation’s Sacramento Service Center. The utility employs full-time pilots and operates under 14 Code of Federal Regulations Part 91, but strives to uphold the higher operations and maintenance standards of Part 135 — or sometimes higher. For example, PG&E determined that Part 135 flight and duty time limits were not adequate to prevent fatigue during survey missions that require intense concentration, so pilots flying lidar missions are limited to six hours of flight time per day.
“Our mission is different than most aviation organizations that are out there to really make a profit,” Doyle noted. “Ours is purely an expense to PG&E — we have no real purpose other than safety.”