As the proliferation of unmanned air systems into new roles continues, rotary-wing UAS specialist Dragonfly Pictures Inc. (DPI) is developing a large, tandem-rotor vehicle aimed at autonomous heavy-lift applications ranging from agricultural aerial spraying to air supply for military forward operating bases.

Resembling the configuration of the CH-47 built at Boeing’s nearby Philadelphia facility, the tandem-rotor DP-14 Pelican prototype is expected to make its first flight early in 2016. Considered large by the standards of conventional rotary-wing UAS, the Pelican will be 13.5 ft. long and is designed to carry up to 450 lb. of payload within its 26 cu. ft. of cargo space or on external hard points. The vehicle is powered by either an 87-hp Solar T62 engine or 133-hp Microturbo eAPU turbine and is designed to operate on JP-5 or JP-8 heavy fuel, generating 4.2 kw of power for avionics and sensor payloads. 

“We think tandem designs hold a lot of advantages over single rotors, which are like most of the UAVs you see today,” says Bud Cary, DPI chief operating and financial officer. “Single-rotor UAVs do not necessarily work as well in certain applications, especially when you have to fly somewhere remote where you don’t really know what the terrain is like. The tail rotor is what gets damaged by debris, plants and bushes. Tandem rotors are higher and have a wider center of gravity, offering greater loading flexibility.”

The proof-of-concept display version, unveiled at the  HAI Heli-Expo in Orlando, Florida, in early March, was shown with external tanks and a spray bar rig for agricultural applications developed by Oregon-based Isolair Helicopter Systems. For this role, the system will likely be offered with nose-mounted sensor systems such as lidar (light detection and ranging) and visual cameras.

“On precision guidance, one of the visions is to put advanced sensors on the front that are capable of detecting which plants need applications,” says Cary. “Right now sprayers [by helicopter or aircraft] cover the whole field, yet sugar growers, for example, might only need to kill weeds on 10% of the area. So 90% of the material being put down is wasted. We want to get it to the point on an application-cost-basis per hour that is competitive to anything that exists now and, because it won’t waste all that material, it will end up being less expensive,” he adds.

DPI also hopes to attract military interest in the Pelican, particularly since a smaller derivative, the DP-12 Rhino, is being evaluated by the U.S. Army. Also configured with a tandem rotor, the 6.7-ft.-long Rhino is designed to carry payloads of 32 lb. for 4.5 hr. or 150 lb. for 1 hr., and can be programmed to follow preloaded GPS coordinates to a landing site.

A version of the DP-14 will also be used under a joint project with NASA to study airworthiness requirements to support FAA certification for UAS that weigh 55 lb. or more, specifically for use in precision agriculture. DPI, which began the work with NASA in May 2014, says the agricultural variant is expected to be the first UAV over 300 lb. to operate with FAA certification.