Last week, Undefined Technologies (UT) a startup drone company based in Miami, Florida, successfully completed a test flight, powered by ion propulsion, that demonstrated significant increases in lifting power and mission time. The flight only lasted 2 minutes and 30 seconds, but the UT team was able to test the aircraft’s performance, flight dynamics, endurance, and noise levels. Two big takeaways: 1) the flight time increased by five times from the prior version of the drone; and 2) the noise levels generated by the drone were less than 85 decibels (the point at which a noise is considered “excessive”).

To understand the subjective nature of noise, the commonly used Noise Scale below compares the levels of noise in decibels (dB) to everyday examples of noise

110dB+ Jet engine at about 100m
100dB+ Jackhammer (pneumatic drill) at close range
80dB+ Loud highway noise at close range
70dB+ Louder traffic
60dB Quiet traffic noise.
50dB Louder conversation.
40dB Quiet conversation.
30dB Birds flying by.
20dB Watch ticking.
10dB Rustling or falling leaves.

By continuing to test this ion propulsion drone, UT hopes to conduct even longer flight times and achieve noise levels below 70 decibels.

UT has also joined the Aviation Sustainability Center (ASCENT-AERO) to assist in creating science-based solutions to help reduce the environmental impact of aviation. ASCENT-AERO’s goal is to create sustainable aircraft with zero carbon emissions and minimum noise.

UT hopes their drones can be used as the “last mile delivery” solution in urban areas where noise from drones is a large concern. The ultimate goal is to bring a silent drone to the market. More testing and further understanding of the physics will continue, but in order to fully integrate drones into our daily lives, the public would like to see the noise emanating from these drones eliminated or, at least, made unnoticeable. Of course, now comes the concern that there could be a silent drone hovering above you … that you don’t even know is there.