It’s not easy for a power company to chalk up a 99.999 percent electricity reliability rating, but the Tennessee Valley Authority has been doing it for the last 19 years straight. Helicopter pilots and linemen are an integral part of this achievement.
People outside the industry sometimes envision these pilots and linemen as a bit loony, and for good reason. The Tyler benches attached to the outside of helicopters commonly touch 500,000-volt electricity lines while linemen transfer themselves from the benches onto towers that stand as high as 300 feet in the air. While the lines are de-energized, their proximity to the helicopters and their spinning rotor blades is hair-raising to the uninitiated.
Ask TVA Helicopter Operations Manager Adam Hammond whether the pilot or lineman is loonier, and he’ll quickly point to the other guy.
“Definitely the lineman,” Hammond said. “They’re out there operating in all kinds of weather to get the power back on.” When rain grounds the helicopters, the linemen have to climb the towers instead.
In all seriousness, though, Hammond explained that TVA helicopter pilots and their linemen must not be risk takers because of the inherent risks of working on giant electricity towers.
“If you’re a cowboy, this is not the place for you,” Hammond emphasized. “Precision long line and power line operations, in my opinion, is the most precise flying you’ll do as a helicopter pilot.”
Hammond clearly enjoys his job and enjoys working for this unique government agency, which was created to bring economic development to the Tennessee Valley as part of the Depression-era New Deal. Helicopter operations have been part of the TVA from the beginning.
“I think that it’s the type of work being completed, and the ability to work with linemen who take a lot of pride in their work,” Hammond explained of his affinity for his work. “Also knowing that the type of flying I do helps provide power to millions of people.”
The TVA fleet’s three new MD 530F helicopters help TVA work safely, he added. Hammond noted features such as the MDHI F-model’s glass cockpit that expands his field of vision, its synthetic vision system, and its digital instrumentation that makes the aircraft lighter so it can carry more equipment or produce more power when needed. A team of TVA flight members just attended the HAI Heli-Expo to display one of their new MD 530Fs at the MD Helicopters booth.
“It seems like (the MD 500 series) was just built for this kind of work,” Hammond said. “It makes everything very stable.” Originally a light scout and attack helicopter in the Vietnam War, it now features a larger engine but the basic airframe remains the same, he said. It’s great for hovering and windy conditions.
Lynn Tilton, Chief Executive Officer for MD Helicopters, Inc. (MDHI), agrees that the MD 530F is built for utility work.
“The MD 530F is revered for its safe, reliable and cost-effective operation in a broad range of utility missions,” Tilton said in a news release late last year announcing TVA’s third MD 530F.
TVA’s latest MD 530F is the first commercially delivered F-model with MDHI’s newest all-glass single-engine cockpit that includes Howell Instruments’ Electronic Engine Instruments and Crew Alert System (EICAS); Garmin G500[H] TXi Electronic Flight Instruments (EFIS) with Touchscreen GDU 700P PFD/MFD; and Garmin GTN 650 Touchscreen NAV/COM/GPS, the techie MDHI news release explained. Additional mission equipment includes the Fargo 21-gallon auxiliary fuel tank, Onboard Systems Talon LC Keeperless 3,600 pound Cargo Hook and Colorado Helicopters Side Hook Bracket, high visibility main rotor blades, and wire strike protection.
“We found that using helicopters with this new technology is cost-effective for TVA’s precision work,” said Kevin Featherston, TVA senior contract manager who oversees aviation fleet purchases.
“This type of flying really makes you use all your skill sets day in and day out,” Hammond added. “Every day is different and very challenging.”
Take, for example, one day when Hammond and a lineman flew out to investigate the cause of a power line failure. About 200 feet from one tower, they spotted what appeared to be a stick hanging off an insulator. As they closed in, they realized it was a four-foot-long snake that had climbed about 80 feet up the tower and out one arm before it zapped the power line and proceeded to reptile heaven.
While that was quite an unusual wildlife encounter, another kind is quite common: bird poo. Buzzard droppings are so common on insulators that TVA has invested in a pressure spray wash system so linemen can wash off the avian excrement without having to turn off electricity and climb onto the towers, Featherston related.
TVA’s unique heritage
FDR sought to combine the power of government with the flexibility and initiative of private enterprise when he convinced Congress to create the TVA as sort of a pilot project in 1933. As a federally owned corporation, TVA has more flexibility than a government department, Featherston said. TVA is now entirely self-financed and receives no tax dollars, while making tax-equivalent payments to state governments.
TVA is by far the largest of only a few public power providers in the country, one of the largest electricity producers in the country with a generating capacity of about 32,000 megawatts, and the first and largest regional planning agency for the federal government. Its 80,000-square-mile service area covers most of Tennessee and parts of neighboring Alabama, Georgia, Kentucky, Mississippi, North Carolina and Virginia. TVA can sell power to a limited number of other outside power companies but is restricted by federal guidelines that were established in 1959, Featherston explained.
TVA provides low-cost power to nearly 10 million people through 154 local power companies, 57 large direct-served customers and federal installations. TVA’s generation comes from a diverse portfolio including coal, nuclear, hydro, pumped storage hydroelectric, natural gas combustion turbine and combined cycle gas; alongside solar energy, wind energy and other generation sources.
Since part of TVA’s original mandate was to build dams for flood control and power generation, TVA also manages more than 293,000 acres of reservoir land and 80 public recreation areas in the Tennessee River Valley. A study from TVA and the University of Tennessee shows that the annual value of recreation on the Tennessee River reservoir system for the region is nearly $12 billion.
Economic development to increase Tennessee Valley residents’ standard of living has been a huge part of TVA’s congressionally mandated mission from day one. Site Selection, an international industrial development magazine, has recognized TVA for 12 years in a row as one of the Top 10 utilities in North America for economic development leadership and results.
“We’re constantly seeking to bring in new business, so we use helicopters for that as well,” Featherston said. The rotorcrafts carry prospective new business owners to potential industrial development sites. Toyota, Volkswagen, Google and Facebook are among the major businesses that TVA recently helped woo and convince to locate in the valley. Reliable electricity was a factor in their decisions.
Strategic Fiber Initiative
TVA currently is in the midst of installing up to 3,500 miles of additional fiber-optic lines onto its existing power line system, traversing its entire service area. Transmission towers are an optimal place to string fiber-optic cable. High-voltage transmission lines have an overhead ground wire on the towers above the conductors. This wire is used to shield the lines from lighting strikes. To install fiber, TVA pulls out the old ground wire and replaces it with optical ground wire, which shields the lines but also includes fiber-optic cable inside. TVA’s helicopter fleet is making this project faster and more efficient with the ability to carry three linemen, dropping one at a time onto a tower in as few as 15 seconds and then hopscotching ahead.
“The grid of the future requires a lot of data, and potentially doubling the footprint of our fiber-optic network will help us get there,” Featherston said. TVA uses the fiber-optic network for operating, monitoring, and protecting the power system.
In addition to the operational benefits, this initiative may provide a major economic development boost to the Tennessee Valley. “This fiber network aligns with the TVA mission,” Featherston said. “We want to improve the quality of life for people in the valley.”
Diverse missions require diverse air fleet
With such a wide variety of missions, it’s no wonder that TVA has utilized a diverse aviation fleet to meet its needs. Using helicopters instead of bucket trucks can save money because linemen can restore power up to four times faster, Hammond said. While some competitors contract out flight work, TVA leaders believe it’s better to be in control of maintenance, training and safety, Featherston said.
The TVA fleet features nine helicopters (and two fixed-wing crafts), requiring mechanics to be tooled up for three different helicopter manufacturers and four different airframes. Featherston looks for the “best value” over cost, although he said the low bidder still ends up getting the contract about 80 percent of the time. Flight employees include five line pilots, two flying managers, three mechanics, a director of maintenance, and two admin personnel. Four of the pilots and two of the mechanics are mil to civ, including one Brit. Helicopter operations and maintenance are headquartered in Muscle Shoals, Ala., at TVA’s main aircraft hangar, a 1936 structure on the National Register of Historic Places.
TVA uses its three MD 530Fs for close line work such as transferring lineman onto towers and construction; two Airbus EC120s for line patrols, since they can fly relatively longer without refueling; two versatile Bell 407s for construction lifting, line inspections and TVA executive/corporate executive transportation; and an Airbus EC145 for TVA executive/corporate executive transportation. Bell and Airbus happen to run production facilities in the Tennessee Valley, too, Featherston noted.
The fixed-wing aircraft fly TVA executives to farther locales such as Washington, D.C., where they often conduct business. And the twin-engine EC145 comes in handy when important economic development missions need to take place during bad weather, since it can fly IFR.
“It’s nice to know I’m flying a mission that’s going to create thousands of jobs for people in the valley,” said Hammond, who didn’t realize economic development work would be part of his mission when he took the TVA job.
Sometimes TVA aircraft also help fellow power companies and emergency management officials during times of need such as natural disasters. Last September, for example, TVA crews flew in supplies and helped assess Duke Energy power line damage from Hurricane Florence. That was a mission dear to Featherston’s heart, since his daughter had to ride out that hurricane while reporting for a local TV station.
“We are competitors, but we’re also in it together,” Featherston said of the neighboring power companies, noting that they depend on interlocking grids. “And that’s different for our industry than others.”
Keeping transmission lines in shape
The TVA fleet spends much of its time making sure that 16,000-plus miles of transmission lines remain 99.999 percent reliable. By law they must check the entire system at least every three years. They inspect rights-of-way annually to make sure lines are clear of vegetation.
“Reliability is one of the driving factors for new industry to come in and build here,” Hammond said. “We’re always using helicopters for routine maintenance, construction and inspection,” Featherston added.
TVA pilots and linemen can cover about 200 miles of line per day during inspections. If they see a problem during inspections, they call in a ground crew and keep flying. They can go two hours before refueling. One of the most common repairs is replacing cotter keys that back out of screws holding insulators on towers. The keys can loosen up after a few years of vibrating in windy conditions. Linemen also are on the lookout for the aforementioned buzzard droppings, which can cause insulators to conduct electricity instead of insulating it.
Flight crews use LIDAR for about a week of each month for the ROW inspections, measuring the distance between tree branches and towers and measuring how much lines are sagging. They also use LIDAR and piezometers to check coal ash storage for safety. Infrared instruments seek out transmission line hot spots caused by lightning strikes and other issues.
While most TVA air fleet hires bring previous experience, they need plenty of specialized continued training. Training includes three tiers: technical, human performance and professional development, Hammond related. Every pilot and mechanic attends factory school training at least annually and flight safety training at least twice annually. Dunker training is scheduled for everyone this year.
“Anything they can find that will make them a better person, we’ll send them,” Hammond added. For example, a couple pilots are interested in NTSB investigations training so they’ll get that this year, too.
The flight program has IS-BAO stage 1 certification and will get its stage 2 audit this year. All pilots are safety officers, and mechanics have a ground safety officer.
“We’re very good at risk management,” Hammond said. “It’s not a very dangerous environment, but it’s very unforgiving if something goes wrong.”
The biggest danger is wire strikes, Hammond said. Another is static electricity when linemen are transferring from helicopter benches to towers. Linemen must carry a large-gauge wire called a ‘bond’ and attach it to the deactivated power line when transferring to the tower, then clip it back on the helicopter when transferring back.
Losing power while hovering around transmission towers is another danger. Most of the ROW is cleared enough to allow rotorcraft to drop and land in a 30-foot area. If not, the linemen have to climb the towers instead of transferring from a helicopter.
Drones of the future
TVA is just starting to get into UAV technology, with two drones and a dedicated employee.
“It’s all about safety,” Featherston explained. If TVA can use a UAV instead of a helicopter and lineman on a tower, it’s obviously safer for humans.
“At one time it felt like they were competing with pilots, but they’re really not,” Featherston said of the drones. “They complement each other.”