Perhaps it’s high time we reevaluate the way we teach people to fly, envisioning a future where we glide around the traffic pattern under electric power rather than noisily propelling through the atmosphere by burning fossil fuels.
The idea of electric flight, much like many dreams, holds a certain allure but may not be feasible at present. However, there’s a glimmer of hope that it could become a reality in the not-so-distant future.
Over six decades of flight training, I’ve had to adapt to numerous changing requirements. With the current state of electric powertrains, significant adjustments to training procedures would be necessary to accommodate the existing limitations of battery-powered flight. The main drawback for now is the limited endurance compared to traditional avgas-powered trainers. Range anxiety, a well-known concern for electric vehicles, becomes even more pronounced when in the air rather than on the road.
Flying lessons powered by electricity would necessarily be brief with current technology, similar to the 30-minute “discovery flight” introductions we offer to potential flight students. CFIs would need to make the most of every minute in the air, adhering to a precise flight profile and swiftly transitioning from one demonstration and practice session to the next. Electric flight management does offer some flexibility as reducing power demand significantly extends endurance. At a slow cruise, an electric trainer can efficiently log time, as long as there’s sufficient battery reserve to return to the runway.
Another challenge would be maintaining the student schedule due to the lengthy recharge time after a depleted battery pack. We typically space students 30 minutes apart, allowing just enough time for preflight and postflight briefings, ground school, and paperwork. Unless a freshly charged e-trainer is readily available, it might be necessary to engage in simulator or classroom sessions until the charging is complete.
Staying close to home during level flight seems to be the key to maximizing the available battery output, but flying is not just about that. We fly and teach to prepare students to use airplanes to travel. A flight of approximately 50 nautical miles meets the FAA’s definition of a cross-country flight for private pilot training, but airports are often not ideally located to support this minimum requirement. Training legs of 75 miles or more are often necessary. For a light sport airplane (LSA) certificate, shorter flights of 25 and 50 miles are legally acceptable, making today’s electric trainers more suitable.
It remains to be seen if the FAA will make provisions for certifying electric-powered airplanes in the special-LSA category. The European Union Aviation Safety Agency (EASA) has awarded its ultralight category certification to electric airplanes, but the FAA currently has no similar provision. However, on March 1, the FAA approved an exemption for the Textron/Pipistrel Velis Electro to operate as an LSA.
Today’s available e-planes can fly for about 30 minutes before concerns about remaining endurance arise, requiring a return to the home base, followed by 90 minutes of recharging. Thus, it seems that effective cross-country training will have to rely on internal combustion flight for the time being.
This leaves an electric training aircraft to perform its essential tasks in a nearby practice area, teaching basic skills such as turn coordination, slow-flight transitions, stall recovery, and ground reference maneuvers. Flying several miles to and from a designated practice area would reduce the time available for training. My policy has always been to conduct local flight training in an area upwind of the airport to avoid fighting a headwind when the training period is nearly over. This would be crucial when the electric airplane’s state-of-health meter approaches the red zone.
What about traffic pattern work, where the e-trainer might seem most suitable? At their maximum power output, such as during takeoff and climb to pattern altitude, electric motors can tend to overheat, and battery reserve rapidly depletes. Adding a liquid cooling system is one solution, but it comes with a weight penalty. Performing touch-and-goes from short approaches may not provide enough time to dissipate heat buildup between climbouts. Interspersing level-flight maneuvers with pattern practice might offer a way out.
A training aircraft needs to be robustly constructed to withstand the inevitable rough handling by novice students. Our current range of light sport airplanes, limited to a gross weight of 1,320 pounds, has struggled to gain a foothold in the flight training market for this reason. While it’s true that lightweight airplanes respond easily to gusts and require more active control, the current 1320-pound LSA weight limit can impact their durability in training. A heavy airframe means added weight, something an underpowered electric aircraft must avoid to accommodate sufficient battery capacity. The two batteries in Pipistrel’s Velis Electro trainer weigh over 300 pounds, although the 77 hp (66 hp continuous) motor is a fraction of a piston powerplant.
Saving money is often touted as a benefit of going electric. The direct operating cost of electric trainers is only a few dollars per hour for replacing the consumed electricity. However, when considering overall expenses, one must factor in that the airframe is not inexpensive, and the batteries will need replacement as they accumulate charge cycles. Therefore, there may not be a significant difference in rental rates between similar fuel-burning and electric models.
There’s the perennial promise of advancements in battery technology, which could eventually expand the range to practical limits. A key requirement will be the acceptance of rapid recharging or a means to quickly swap depleted battery packs for freshly charged ones. A quick-charging capability might not be compatible with the goals of minimizing weight or delivering high power output.
Weight-wise, the energy density of gasoline is significantly higher than battery storage, by a factor of 50. This 50:1 ratio is not specific to aviation but is commonly quoted in engineering. Electric power enthusiasts counter with the efficiency advantage of electric motors, which can reach up to 90 percent compared to 35 percent for gasoline engines. Despite its inefficiency due to heat losses, piston-engine power still outperforms the electric motor by 15 times. The superiority of chemical energy sources allows for heavier airframes and additional power for features like cabin heating and extra avionics. The weight of the stored energy in a tank of 100-octane avgas decreases during flight as the fuel is consumed, enabling designers to set a takeoff weight higher than the maximum landing weight. Electric energy sources weigh the same at landing as at takeoff, so the e-trainer’s structure must be capable of carrying this dead weight at the end of the flight.
There’s the intangible benefit of doing the right thing for the planet, flying on a supply of moving electrons rather than burning refined fossil remains, with no environmental pollution and much less noise. This assumes that the necessary power generating station somewhere generates zero pollution during its construction, operation, and replacement. If these concerns and acceptable solutions are of paramount importance to future generations, electric flight training may eventually become the norm.
