Bell's 525 Relentless is continuing its long journey to certification after the company completed cold weather testing recently.
The Bell 525 is a super-medium-lift twin powered by two FADEC-controlled GE CT7-2F1 turbo-shaft engines designed to carry up to 19 passengers. When certified, it is expected to be the first commercial helicopter in the world with fly-by-wire (FBW) controls.
Bell conducted the cold-weather testing at Yellowknife in Canada and Marquette in Michigan to evaluate the 525's performance in harsh environments as part of a planned capability expansion after the type is FAA-certified.
"FAA regulations require operators to validate aircraft performance in every condition the aircraft may encounter," said 525 Deputy Chief Engineer Doug Hamelwright. "Environmental testing ensures the aircraft is ready for these real conditions before being deployed in those environments.
"Yellowknife offers reliable access to temperatures down to minus 40 degrees*, clear flying days and the facilities needed to support our team and aircraft. We evaluated engine and system start-up, warm-up behaviour, handling qualities and performance in dense, cold air. Overall, the aircraft performed very well."
Bell is aiming the 525 at offshore oil and gas industry primarily, but the company is also targeting defence as one of the major applications for the 525, involving the US Army in evaluation and data collection on the Michigan tests.
"Marquette benefits from lake-effect conditions that bring moisture into winter systems moving through the area, making it an ideal location for icing testing of rotorcraft," Hamelwright said.
"In both of these off-sites, our flight test team learned a great deal about operating our aircraft in these environments, which we believe will benefit our customers."
Bell 525 test pilot John Brodnicki told Bell media that the testing went well beyond that required for FAA certification.
"Our focus was to demonstrate compliance with certification regulations and mature the aircraft for real-world customer use," he said. "Beyond initial type certification, we completed additional campaigns in extreme cold, snow, high altitude and icing to ensure the aircraft performs safely across its full designed operating envelope.”
The Relentless has been a long time coming. Bell announced the development program in February 2012, with the first flight in July 2015. The project hit a tragic roadblock in 2016, when the prototype crashed during testing, killing both test pilots on board.
At Rotortech in June 2024, Bell said it was expecting certification by the end of that year. The company has provided no further update to Australian Flying.
*at minus 40 degrees, Celsius and Fahrenheit are the same
- Steve Hitchen