Two, a small and a large, optional auxiliary fuel tanks are available for the R66 Turbine helicopter. The small tank, dubbed the Slimline, holds 23.2 gallons (88 liters), and adds approximately 1 hour to helicopter endurance and extends its range by as much as 100 nautical miles (115 statute miles). It mounts on a fiberglass tray that installs in the aircraft’s baggage compartment, occupies one-third of the space, and leaves room for up to 200 lbs. of baggage. Both tank and tray can be removed when not in use. The tank weighs 29 lbs. when empty and 189 lbs. when full of fuel.
The 43.5-gallon large aux tank extends the helicopter’s range by approximately 2 hours or as much as 200 nautical miles (230 statute miles). The fuel tank mounts on a fiberglass tray that installs in the forward section of the baggage compartment. The tank occupies two-thirds of the compartment, leaving space for up to 100 lb of cargo. Both the tray and tank can be removed when not needed. The system weighs approximately 37 lb.
Both tanks include crash-resistant fuel bladders that fit in an aluminum and fiberglass enclosure with an internal fuel pump that transfers fuel to the helicopter’s main tank at approximately 40 gallons per hour. Aux Tank Controls are conveniently located in the upper instrument console and feature an ON/OFF switch, a NO FLOW annunciator light, and a FUEL QUANTITY button.