The next logical step in the world of unmanned aircraft is endurance but this typically requires larger, more expensive aircraft to accomplish the task. For years, designs have been entered into the field to broaden unmanned aircraft range capabilities and there have been both successes and failures. One potential groundbreaking candidate is the Vanilla Aircraft VA001 Unmanned Air System (UAS) which recorded its first-flight back in February of 2015 and continues in development today (2017). The aircraft was born from a five-person team in Falls Church, Virginia with the purpose of building economically-minded, compact design to haul payloads over very-long-distances.
The VA001 is categorized as a mid-sized UAS and features an efficient diesel-fueled engine driving a propeller unit in a "pusher" configuration. The aircraft sports straight, high-mounted mainplanes to achieve desired lift-versus-drag balance and its fuselage shape is akin to a tear drop for aerodynamic efficiency. The outer panels of the mainplanes are upturned. Overall wingspan measures 36 feet. The tail unit is made up of a single vertical fin with the horizontal plane set high.
The 475lb VA001's can carry a payload of up to 30lb. It lands without an undercarriage, coming down on its belly before rolling to a complete stop. The propeller unit at the rear of the body collapses so as not to incur damage during the action.
As development of the VA001 is ongoing, engineers will continue to push the boundaries of this intriguing aircraft. As it stands, the aircraft can fly for up to ten days under quiet operation at altitudes of 15,000 feet and speeds up to 75 knots. It can loiter (under autopilot) in orbit while traveling at around 55 knots.
In January of 2017, the Vanilla Aircraft crew claimed a World Record with a recorded unrefueled 56-hour flight, the longest for an unmanned combustion-powered aircraft. Range restrictions and icing potential ended what was a planned 120-hour test flight.
In an October 2017 test flight involving NASA/DARPA, the VA001 completed a journey lasting 121 hours, 24 minutes - this covering some 7,000 miles. This showcases the aircraft's impressive inherent range capabilities and the system was still left with another three days of fuel in its onboard stores. The action marked broke the previous endurance record for longest unmanned internal combustion-powered flight.
The VA001 certainly has commercial and military implications and is especially of interest to both for its low cost function and impressive performance. In the latter, the product is seen as a potential support system at the platoon level where it can be used for long-endurance reconnaissance as well as modest-sized cargo delivery.