Reliable Completes Detect-and-avoid Tests Near Airports

Reliable Robotics has completed a series of FAA-contracted flights designed to test whether large uncrewed aircraft systems (UAS) can safely share airspace with crewed aircraft near airports.

The Mountain View, California-based company staged deliberate encounters between its autonomous Cessna Caravan and other aircraft in and around the traffic pattern at Hollister Municipal Airport (KCVH) in California. These flights were intended to evaluate how its detect-and-avoid (DAA) system performs at the boundary between en route and terminal airspace, where aircraft are transitioning between the cruise and approach flight phases.

Testing confirmed that the FAA-developed Airborne Collision Avoidance System X (ACAS X), the algorithm that underpins Reliable’s autonomous flight technology, behaves differently in terminal airspace than en route—consistent with how IFR pilots adjust their procedures when interacting with VFR traffic, according to Reliable.

“Demonstrating the ability of UAS to integrate into airport environments with a VFR traffic pattern is necessary for building a scalable aviation autonomy solution,” said Brandon Suarez, the company’s v-p of UAS integration. “The data Reliable captured through this testing under the FAA is nearly impossible to generate in a lab environment, and is tremendously useful in the development of relevant and useful standards.”

ACAS X is the FAA’s successor to TCAS II, the collision-avoidance system carried by most commercial airliners. ACAS Xu is the variant developed for autonomous fixed-wing drones. Reliable’s system uses it to alert remote pilots to both cooperative and non-cooperative traffic and advise them on avoidance maneuvers.

Sagetech supplied prototype ACAS X avionics for Reliable’s flight testing campaign, while Collins Aerospace provided a prototype ground-based radar, and uAvionix contributed prototype C-band radio equipment. Virginia Tech’s Mid-Atlantic Aviation Partnership also supported the campaign.

“Real-world testing advances the substantiation of standards that we rely on to build DAA solutions that keep our skies safe,” said Sagetech chief technology officer Matthew Hamilton.

Results have been submitted to RTCA Special Committees 228 and 147, which are developing standards for advanced DAA systems.

Reliable, which is developing its autonomous flight control system for both commercial and defense customers, said the testing is a step toward routine UAS operations in controlled airspace.