Throwback Thursday: MicroTau’s First Flight Test

You’ve come a long way, baby!

Today, MicroTau is focused on demonstrating product performance across a number of flight test programs, including with the US Defense Innovation Unit (DIU) and Air Force Special Operations Command (AFSOC) and other commercial aviation partners.

However, way back in 2021, we commenced the flight test program for our drag-reducing ‘shark skin’ riblet product by way of conducting our very first flight tests with Matt Hall Racing, Australia’s only Red Bull Air Race team and winner of the final 2019 championship.

With a solid repository of laboratory-based evidence of drag reduction effectiveness, primarily in wind tunnel testing by Lockheed Martin, this flight test marked a critical step in validating the technology's implementation and performance in a real-world environment.

Not quite Chuck Yeager, but close

The flight tests were conducted by Matt Hall, a highly experienced pilot with a background as a former RAAF F/A-18 pilot and instructor. Hall's expertise was instrumental in thoroughly evaluating the prototype.

The chosen aircraft for this program was a Zivko Edge 540, an aerobatic aircraft known for its robust performance capabilities, including the ability to withstand up to 12G and achieve a roll rate of 420 degrees per second - far in excess of our product’s typical operating conditions. A light aircraft is the ideal platform for the first flight tests of this product as it allows for rapid product application, near-immediate flight testing, and data analysis.

Trial by flyer

Throughout the test flights, the Zivko Edge 540 underwent a series of high-intensity maneuvers, including sustained high G-force turns that culminated in stalls, exceeding 10G in some instances. The prototype riblet film, applied to both the wing and aileron surfaces, successfully endured over twenty repetitions of these strenuous maneuvers. Crucially at this early stage of development, observations confirmed that the application of the riblet film did not negatively affect the control or flight characteristics of the aircraft, ensuring no adverse impact on safety or handling.

A game of telemetry

The primary objective of these initial tests was to gather preliminary data on the riblets' performance-enhancing capabilities. Onboard telemetry systems were used to record various parameters, including indicated airspeed and engine power output. These systems, while simplistic compared to the advanced telemetry systems employed in modern commercial and defence aircraft, measured a performance improvement of 1-2% with the riblet product applied only to the wings.

Key Outcomes and Future Direction

This inaugural flight test program was a significant milestone for MicroTau. It demonstrated a sound and efficient method for applying the riblet film to aircraft wings and confirmed the film's durability at speeds exceeding 220 knots (400 km/h) and under forces of 10+ Gs - just three years later, we demonstrated durability in excess of Mach 1. The tests also confirmed a sizable performance improvement resulting from application of the product prototype to the wings of the aircraft. Unfortunately, the Red Bull Air Race series has not been revived since ending in 2019, so the shark-skin wrapped Zivko Edge never flew in competition.

The successful completion of this initial program laid the groundwork for the more extensive and rigorous flight test campaigns that have followed, including on a US Air Force Lockheed Martin C-130J and numerous commercial airliners. The completion of these later flight tests also reflects significant maturation of our manufacturing systems - the Zivko Edge flight tests required just 10 square metres of the riblet product, whereas the C-130J required several hundred across its wings and fuselage. 

We’re now expanding our flight test program, targeting commercial airliners and defence transport aircraft. If you’d like to be considered for your aircraft to participate in this program, please get in touch. 

To read more about the flight tests with Matt Hall including details of the flight test regime, riblet configurations, and data corrections, see our SciTech paper titled ‘Advancements in Drag-Reducing Riblet Film Production for Aviation and Other Applications’