Defying the Elements in the Southern Hemisphere: Blackbird Drone Surpasses 658km/h Mark

The team behind the ‘Blackbird’ drone set out to break the world speed record, pushing the limits of technology to achieve speeds that no electric drone had ever reached before. Their pursuit involved radical design changes, devastating crashes, and extreme environmental challenges.

The Propellers – To push into new territory, the team relied on new, custom-made carbon fibre propellers featuring an extreme pitch and a distinctive sawtooth leading edge. The sawtooth design was intended to keep the airflow straight over the blades, reducing span-wise flow and thereby improving aerodynamic efficiency. Although the exact pitch of the blades was kept a closely guarded secret, it was significantly greater than their previous APC propellers, raising initial concerns about whether the drone would even be able to take off. Conveniently, the new carbon fibre blades dropped straight into the old spinners without requiring any modifications.

The First Crash and Signal Loss Theories – During a test run, the drone achieved a speed of 630km/h but was lost after the pilot completely lost the video feed. The team could not retrieve the drone, describing the massive search area as a needle in a haystack. To explain the catastrophic video failure, they established three working theories:

1. Antenna geometry: Both antennas were situated on either side of the drone’s battery in the exact same orientation, meaning they shared the same blind spot.
2. Doppler shift on the digital link: Radio waves are subject to the Doppler effect, much like sound waves. As the drone flew past at extreme speeds, the radio frequency flipped from being compressed to stretching in less than a tenth of a second, which was faster than the goggles’ receiver could track.
3. Signal overload: At close range, the signal level spiked to be a thousand times stronger as the drone screamed past; the receiver was simply unable to readjust fast enough before the drone crashed.

Ultimately, the team believed that the crash was caused by a combination of all three factors stacking on top of each other.

The Second Speed Attempt With only one drone left and no room for error, the team made a second attempt the following day in highly unpredictable and windy conditions, with gusts reaching up to 60km/h. The ultimate goal was to average over 700km/h.

During the run, the drone reached an astonishing top speed of 730km/h. Pushing the hardware to its absolute limits, the machine pulled 400 amps for about 10 seconds. This immense power draw caused the batteries to reach 80C, generating enough heat to physically melt the heat shrink. Fighting the intense wind, the drone managed 640km/h on the return upwind leg. By combining the two speeds, the team achieved an average of 685km/h. While it fell slightly short of their 700km/h goal, the run successfully surpassed the existing official Guinness world record of 658km/h. Despite the brutal weather conditions and thermal damage, the drone landed in one piece, leaving the team confident that with further tuning, they could push the record even higher.