The Future of Advanced Air Mobility

How HUMS Technology Could Support Cost Effective Maintenance For eVTOL Aircraft

Health and usage monitoring systems (HUMS) have proven their worth with helicopter operators, providing a way to flag up any technical problems that could undermine safety. The information they generate about the performance of the aircraft and its various systems also provide predictive trend analysis, which allows maintenance to be conducted in a more cost-effective way. For instance, HUMS can show the rate at which components are likely to need replacing so that support crews can plan on doing this work whenever the aircraft is next booked for maintenance, rather waiting for them to fail.

Vermont-based GPMS says its low-cost, Cloud-based Foresight MX HUMS could add a lot of value for new generation electric vertical takeoff and landing (eVTOL) aircraft. The company recently provided the system for evaluation of Beta Technologies’ new Alia prototype.  

According to GPMS founder and CEO Eric Bechhofer, the availability of a low-cost, lightweight and flexible HUMS solution could be especially valuable to eVTOL aircraft, which will likely have to perform a high number of movements each day to earn their keep. In the context of high-volume urban air mobility operations, he argued, aircraft reliability will be especially important, which is where the trend monitoring capability of HUMS could prove especially valuable.

The system is already gaining traction with light helicopters. In 2019, GPMS received FAA supplemental type certificates (STCs) allowing Foresight MX to be used on Bell 407GX and 407GXP single-engine aircraft, and Bell now provides the system as standard equipment on the latest 407GXI model. According to company founder and CEO Eric Bechhofer, further STCs are anticipated this year, including approval for the Airbus Helicopters AS350 AStar. Bell has reportedly expressed interest in Foresight Mx for possible use on its Nexus eVTOL.

The Foresight MX system provides mechanical diagnostics and prognostics, including engine performance monitoring, exceedance monitoring, flight regime recognition, automated data acquisition, and optimization solutions for rotor track and balance. The data can be accessed via a standard web browser on any standard electronic device and users can get automated alerts via email or text message.

“We want to be able to provide better support not only for [aircraft] design engineers but also for maintainers and so it’s important to have a better connection with them,” Bechhofer told FutureFlight. “With HUMS you are doing a virtual aircraft inspection every time you acquire data.”

By building Foresight MX around a Cloud-based, “internet of things” architecture, GPMS says it will be easier to implement improvements to the technology. “In a year from now we may be adding new sensors we haven’t even thought of yet,” said Bechhofer.

GPMS claims that for most applications, the upfront costs for Foresight MX will be less than half of those for legacy HUMS equipment developed for larger helicopters. It says that legacy systems cost between $200,000 and $300,000 per aircraft. The company is looking at providing the system on a subscription-based software-as-service business model that would further reduce the upfront costs for users.

The largest item of Foresight MX hardware is a small box with four-inch by one-inch by seven-inch dimensions and weighing less than a pound. For a recent trial installation on a Bell 206 helicopter, the company was able to fit this outside the cabin and this flexibility could be highly beneficial for even smaller eVTOL aircraft.