By Aidan Wiese
In March, WAPA’s Small Unmanned Aircraft System, or sUAS, pilot program reached its conclusion. These units can be used when surveying and inspecting miles of transmission line, saving both time and money, as well as preserving one of WAPA’s most valuable assets: the safety of its workers and linemen.
The program, which won an Inclusion, Innovation and Technology Award last year, initially began in April 2018. At the time, three linemen volunteered to study and pass the Federal Aviation Administration Remote Pilot License requirements, which would allow WAPA to legally fly unmanned aircraft within line-of-sight operations.
The sUAS program was specifically intended to explore potential ways to use unmanned aircraft in the organization, develop use cases and test their practical applications in the field.
The pilot program successfully determined a number of potential applications for the devices, such as inspection-related tasks for transmission lines and substation equipment. They may also prove to be useful when it comes to vegetation management.
“Those were all the use cases we explored when we were doing the sUAS program and found that all those were beneficial,” said High Voltage Electrician David Katich, who regularly works with this equipment.
As reported in the program’s March 21 conclusions document, the single biggest benefit of the sUAS pilot program involves integrating the unmanned aircraft into WAPA’s maintenance operations, reducing the risk in climbing for craft employees.
“Instead of having to climb the structure to look down on it, we’re able to use the sUAS,” said Katich. “The device is able to look down on the structure rather than look up from the ground. That’s beneficial because you get a more thorough inspection. From the ground during an asset inspection, we see 80-90% of a structure, but the top 10-20% is where the sUAS comes in, because that can only be inspected looking down. We’re looking at the top of crossarms and insulators.”
The use of sUAS units drastically reduces the time required for a job, as well as the number of outages required when performing routine maintenance.
In one instance, at Glen Canyon Substation in Page, Arizona, an sUAS was used to inspect and evaluate the top of the 345-kilovolt power transformers using visual imagery. Without the sUAS, the job could have required up to three different outages in addition to the use of aerial lifts and, of course, the use of proper fall protection.
Work on this scale also requires numerous employee hours to schedule the outages, perform the switching, testing and installation of grounds and inspect the transformers themselves. Ordinarily, this task could take up to 90 employee hours. Using a small unmanned aircraft, the inspection was completed in 15 minutes, all while the line remained energized.
“It eliminates the linemen having to climb any structure if there’s something to just be inspected,” said Aviation Manager Richard Westra. “If there’s any required maintenance, obviously it doesn’t. But if there’s a question about any structure, a perimeter, a fence, anything you can’t see from the ground, that’s what this piece of equipment is used for.”
It can also be used to examine suspected damage from gunshots or lightning strikes on a structure.
Additionally, the devices are useful for verifying the sizes of conductor wires. The North American Electric Reliability Corporation requires that utilities verify the actual conductor wire sizes in the field and compare them to those listed in regulations for accurate thermal ratings.
Using sUAS units, crews were able to physically verify all of the wire sizes on crimps at Flagstaff Substation in Arizona in around 10 minutes, without outages or the need for climbing.
According to Katich, the devices were additionally put to great use during the Desert Southwest facilities ratings verification process, when they were used to verify switch nameplates and conductor jumper sizes.
“We verify the conductor jumper sizes by reading the nomenclature on the dead-end paddles,” he said. “The benefit is that we didn’t have to take bus outages at a substation, where we basically have to turn half the substation off or use aerial lifts and bucket trucks.”
Another benefit comes from streamlining the process when there are needs for proof or documentation of damage before making repairs.
The devices were also used to investigate customer complaints regarding loud popping noises near Granby Substation in Colorado. The sUAS was able to fly within inches of the energized conductor and discover that it was damaged as it was being pulled over a malfunctioning traveler. This gave WAPA the documentation required for warranty work to replace the malfunctioning conductor.
“Drones are not there to replace; they’re there to enhance,” Westra explained. “They are not going to change the need for helicopter inspection or for the linemen climbing the tower. It’s just enhancing the process. In the past, we might think we have a problem and need to verify it, but now the lineman can verify what he’s looking at from the ground.”
Aside from the decreased risk to craft employees and the time savings, the devices also offer a large monetary benefit. The total cost for the pilot program, not including the labor, came out to $12,253. This includes the cost of the units themselves, the software subscription, the drone pilot license test preparation course, additional batteries and FAA registration costs.
This compares favorably to the traditional costs of field work. In one instance, inspections were performed for spacer replacements on 25 towers on a 345-kV transmission line in Craig, Colorado, using conductor carts.
With an estimated rate of approximately $150 per hour for a lineman, an sUAS would take about half an hour to perform the inspection, including travel to each tower. For 25 towers, taking up about 12.5 hours, that would cost about $1,875.
However, if the inspections were done via climbing, the same task would require three linemen, each spending about an hour at each tower. For 25 towers, that would require 75 hours of employee time and cost about $11,250. That alone is nearly the entire cost of the pilot program.
Aviation has already procured 10 IT-approved, American-manufactured sUAS units in addition to the three used in the pilot, with plans to expand further from there.
“The end goal for the program, what we envision, is for there to be an sUAS on every line crew and at every manned substation for craft personnel to use,” says Katich.
“I want to thank the many contributors from Aviation, Maintenance and IT, who have worked very hard to advance the program,” said Executive Vice President and Chief Operating Officer Kevin Howard, the program’s sponsor. “We have also received great advice and guidance from our Office of General Counsel. The team has continuously adapted to challenges and the program has expanded significantly over the past year or two, reaching all of WAPA’s regions and providing a very cost-effective tool that helps us maintain system reliability while minimizing safety risks.”
Westra invites any programs or departments to contact him if they feel they could benefit from an sUAS.
“I think almost every department within WAPA could use it,” he said.
Note: Wiese is a secretary who works under the MIRACORP contract.
WAPA’s Small Unmanned Aircraft System pilot program learned how these units can be used when surveying and inspecting transmission lines, increasing both safety and efficiency. (Photo by David Katich.)
Aviation has procured 10 Information Technology-approved, Americanmanufactured Small Unmanned Aircraft System units in addition to the three used in the pilot, with plans to expand further from there.
Small Unmanned Aircraft System units can reduce the time spent on many maintenance tasks from hours to minutes, all while keeping transmission lines energized.
Last modified on March 5th, 2024