March 18, 2020--TVA’s Unmanned Aerial Systems can cost thousands of dollars each, but thanks to 3D printing technology, new operators are now able to hone their skills on more expendable platforms, before graduating to more advanced aircraft. The 3D-printing initiative is part of TVA’s cutting-edge UAS training program, which incorporates best practices from Middle Tennessee State University and other power producers.
TVA is the first-known energy producer to use 3D-printing technology as part of an internal UAS training program.
“We have caught up quickly and, in some cases, surpassed some peer utilities, when it comes to an in-house program that provides knowledge and training simulations to turn out skilled operators,” said Tim Land, TVA UAS specialist.
The purpose of the program is to equip TVA business units with UAS operators who can deploy drones across the fleet to cut costs and obtain better data with the use of real-time, high-definition aerial photography. The technology is frequently used for inspections, mapping, and project planning.
In some cases, drone inspections and data collection can supplement missions traditionally performed by helicopters.
A 3D-printed drone starts with a digital drawing that is converted into microscopic layers. Once the digital file is loaded on the 3D printer, the nozzle head glides back and forth, again and again, gradually increasing the thickness of the print over time.
“It’s like taking a piece of ham hock and running it through a deli slicer,” said James Manni, UAS Services program manager. “The printer builds it up layer by layer.”
The UAS team has four 3D printers that turn out drone frames with less than $5 worth of material. After a few minutes of programming, the machines are left to print the 15 components required to build the aircraft. The printing process takes about three days.
Once the frame parts are printed, Manni and his team equip each unit with a power system, flight controller, propellers and motors. From start to finish, each drone takes 8-10 hours of assembly.
“From a UAS perspective, 3D-printed drones serve as a double trainer,” said UAS Manager Walt Hodges. “Not only do they provide a cost-effective platform for trainee flight experience, but also give the UAS team working knowledge of how to build a drone, program flight settings, perform maintenance, etc.”
If a trainee crashes a drone during training, some of the components are salvaged and assembled atop another inexpensive frame, as opposed to damaging or totally destroying the more expensive aircraft that are flown later in the course.
Flying a drone at TVA requires two nimble thumbs and a willingness to undergo a 36-hour course packed with flight time and classroom curriculum that teaches Federal Aviation Administration and TVA operating fundamentals.
Students learn how to develop flight plans, avoid critical infrastructure, and identify airspace restrictions, like the 30-mile circle that hovers above presidential motorcades — a no-fly zone that if violated comes with a good chance of imprisonment and a minimum $20,000 fine. “I’m not sure TVA has a shortcode for that,” said TVA Instructor Nigel Jones, UAS Services.
The course is split evenly between classroom and field activities. Flight time is spent with an instructor who grades each trainee on his or her ability to control and maneuver an aircraft through a number of live simulations. Trainees must be able to fly the 3D-printed drone well, before graduating to the more expensive Mavic Pro and Enterprise drone that their business unit has purchased.
“It’s similar to getting a manned pilot’s license. You start in a single-engine trainer, like a Cessna 152, rather than a complex multi-engine jet,” Hodges said. “We want our operators to learn basic handling and maneuvers by line-of-sight, before attempting to pilot from the camera display screen.”
To teach dexterity and flying fundaments, the UAS team relies on the 3D-printed aircrafts, which are stripped down the basic essentials.
“For training, we want something that’s cost-effective and that can be built relatively quickly,” Manni said. “We want our aircraft to have GPS, and a return-to-home function, but we also want the ability to turn these safeguards off so we can simulate an emergency situation in class. The 3D-printed drones achieve all these things.”
Once students feel comfortable flying in open airspaces, they are taught to navigate obstructions through a variety of flight simulations that are performed at TVA’s Bellefonte site, which provides a state-of-the-art training environment. The final practical evaluation involves planning and flying a mock mission in this setting.
“Every business unit has something at Bellefonte to train on that is similar to what they will be flying around when they return to their sites,” Manni said. “Having de-energized training facilities where students can learn to safely fly around equipment and structures is invaluable. I think that’s a big part of what separates our training programs from others.”