NASA tests onboard sensors designed to improve drone safety
In an effort to make conventional aircraft and unmanned aerial vehicles (UAVs) get along, NASA has embarked on the latest in a series of flight tests using specially adapted drones and manned "intruder" aircraft. The purpose is to demonstrate the effectiveness of new technologies and help develop new regulations that will allow UAVs to integrate into the US National Airspace System (NAS).
In the last 20 years, drones have come a long way. Where once they were confined to toy shops or a handful of military reconnaissance units, they are now so diverse, commonplace, and have so many applications that official bodies like the US FAA are finally admitting that room in the sky must be made for these remote controlled and autonomous aircraft.
To help with this, NASA has been carrying out a series of test flight programs since 2012. The latest, Flight Test Series 6 (FT6) is scheduled to begin in September of this year and continue through November.
NASA says the main focus of the test flights will be to evaluate new small, lightweight, and low powered sensors to help conventional aircraft and UAVs detect and avoid one another. In addition, the tests will help in developing performance standards for such systems as well as air-to-air radar.
For FT6, NASA has taken delivery of a TigerShark Block 3 XP developed by NAVMAR Applied Sciences Corporation, which has a wingspan of 21.9 ft (6.7 m), a payload capacity of 95 lb (43 kg), and can stay aloft for 12 hrs. It's controlled remotely using a ground-based cockpit and has been equipped with a smoke generator to allow the crews of the intruder aircraft to track them visually and a nose-mounted DAPA-Lite radar built by Honeywell that uses a fixed phased array to steer the radar beam electronically.using three flat panels.
"The radar system is cutting-edge technology with panels small enough to be carried on a smaller UAS, but still have enough range to see and avoid other aircraft," says FT6 DAA Principal Investigator Michael Vincent. "Our goal for FT6 is to challenge the effectiveness of our DAA (Detect and Avoid) system and Honeywell's radar system as we develop performance standards of unmanned aircraft being integrated in our national airspace system."
Using a fleet of intruders consisting of a twin-turboprop BeechcraftKing Air B200, a Beechcraft T-34C Mentor trainer aircraft, and a two-person TG-14 motorized glider, the tests will determine how well the DAPA-Lite radar works in terms of range and accuracy as it locks on to the intruders and calculates their relative distance, bearing and elevation.
This will allow the onboard computers to alter the drone's flight path to keep it a safe distance away. In addition to this, the avoidance system will alert pilots if there is a problem with a drone in the vicinity and provide relevant information to avoid danger.
The program includes tests involving an intruder aircraft deliberately attempting a head-on collision course with a target zone. NASA stresses that such flights will use an adequate safety buffer to prevent mishaps across the 150 encounters in 26 flights. These will use a series of pilots, who are unaware of the FT6 mission objectives to avoid the problem of the pilot anticipating a solution to a scenario.
"Every decision we have made for FT6 was a result of what we have learned in previous flight tests," says Vincent. "Our journey through each flight test series has been instrumental in the hopes of allowing unmanned aircraft to enter unsegregated airspace in the near future. FT6 will be a big factor on how we can safely integrate unmanned aircraft."