With the exploding popularity of multi-rotor RC aircraft, the market is becoming flooded with models in all sizes and rotor counts. While there are definite variations in quality and performance, nearly all of these models are constrained by the limitations of a pure multi-rotor platform. An upstart company in New Hampshire has created a hybrid multi-rotor design that separates itself from the herd. Its creators believe that this machine retains all of the things that we love about multi-rotors, while adding some useful new capabilities.
The aircraft of note is the FireFLY6 from BirdsEyeView Aerobotics. It is a Y-configuration tri-rotor that has some very unique attributes. The machine’s most obvious feature is its wing--a moot appendage on standard multi-rotors. On the FireFLY6, however, the forward two rotors can tilt 90-degrees to transition the ship from a hovering tri-rotor to a forward flying airplane (where the wing proves quite useful). To equate this capability in full-scale aircraft terms, think Harrier Jump Jet or V-22 Osprey.
What's the Benefit?
Despite their beloved camera-toting abilities, most multi-rotors are only capable of rather pedestrian forward speeds. Flyers that want to cover a lot of ground with each flight are typically forced to abandon the rotors and adopt conventional fixed-wing models. By doing so, they forfeit the ability to hover and operate from confined spaces. These are the same constraints that spurred development of the Harrier and Osprey: the need to take off and land with little (or no) runway and then get where you’re going in a hurry.
BirdsEyeView’s founder Adam Sloan notes that “I’ve long believed that the ultimate flying robot is one that can take off and land vertically, but also transition to efficient forward flight.” As off-the-shelf multi-rotor electronics matured to the point that hands-off hovering was feasible, Sloan began piecing together the elements of his dream machine. By February of 2012 his prototype aircraft was able to execute in-flight transitions from hovering to forward flight.
As you might expect, it is the transition phase that has given Sloan’s team the most grief. He explains, “We had to learn the best techniques for piloting into and out of hover situations through trial and error. Learning how to do so reliably (both in terms of materials used and method of piloting), and getting that dialed-in to the point where it is now, was probably the biggest development hurdle.”
Aside from the potential performance benefits of an airplane/multi-rotor hybrid, Sloan points out that there are longevity perks as well. He notes, “I think those who are familiar with foamies (model aircraft constructed of foam) will find themselves doing a lot less repair work. Vertical takeoff and landing is a much less violent process than your average foamie skid landing (sliding on the ground without landing gear).”
But as with any “Jack of all trades” endeavor, you have to have to make some sacrifices.