A Plug-In Beaver?

January 2020 - How do you flight test a new idea? One line of thought says you use as many existing parts as possible, thus removing as many variables as possible. In the case of Harbour Air's electric airplane, why not start with what you know best: the mainstay of your fleet, the DHC-2 Beaver.

Firewall aft, there is nothing new. It's been the same since 1956, so there are no surprises there. Firewall forward, now that is different. You now have a motor, not an engine; 750 electrical horses de-rated to 450 for redundancy, and it should be really smooth, too, because there is no up-and-down motion of pistons to create vibration, just a nice, round electric motor to hum along.

The motor weighs just 297 pounds, compared to the 690 pounds of the Pratt & Whitney R-985 that it replaced, leaving almost 400 pounds for batteries and other related bits and pieces. Plus the need for the weight of avgas can be replaced by the weight of batteries. At a previous fuel consumption of 28 gallons per hour with the radial engine, you would have another 150 pounds available for batteries for an hour-long flight. You will need those batteries because an extension cord would be a bit cumbersome. Like electric cars, you drive (or, in this case, fly) it during the day and plug it in overnight. More than 2,000 pounds of standard lead acid batteries were used for the test flight, which significantly reduced the useable load of the Beaver. Smaller, lighter lithium batteries currently under development will be used as they become available.

C-FJOS, the Beaver that has been modified, was built in 1956 and reached more than 25,000 hours in service by the 1990s. Later it was modified with an "up-gross" to 5,600 pounds from the original of 5,100 pounds. You can watch a CBC video of the first flight here.

Harbour Air, formed in 1982, today provides service to British Columbia's coastal communities with 80-plus pilots and a fleet of some 40 float-equipped aircraft: Beavers, Otters, Twin Otters, and Cessna Grand Caravans. A significant fraction of its 300 daily flights are local tours around Vancouver and Victoria. These 20-minute sightseeing flights will lend themselves to the new electric-powered Beaver and will provide the significant reduction in carbon emissions that are so desired by environmentalists worldwide. The most optimistic guess for an electric Beaver's entry into service would be 2022. It all depends on the availability of the batteries, and of course, the certification process itself. Everything else works.