Hill Helicopters Fires Up First British Clean-Sheet Turbine Engine in Six Decades

Hill Helicopters has completed the first run of its GT50 turboshaft engine, marking the first time a British company has developed and run a clean-sheet helicopter turbine engine in 60 years. The Staffordshire-based manufacturer announced the milestone this week, describing it as a major step toward certification of its HX50 private helicopter and HC50 commercial variant.

The GT50 is a purpose-built turboshaft designed specifically for Hill's helicopter program. Rather than adapting an existing engine, the company chose to design its powerplant from the ground up, a rare move in an industry where most rotorcraft manufacturers source engines from established suppliers such as Rolls-Royce, Safran, or Pratt and Whitney Canada.

Hill Helicopters founder and CEO Jason Hill said the first run followed years of design and development work by the company's in-house engineering team. According to Hill, the engine started, ran, and shut down as expected during initial testing at the company's facility.

What the GT50 brings to the aircraft

The GT50 is rated at 500 shaft horsepower and is designed to burn a range of fuels, including Jet A, diesel, and sustainable aviation fuel. Hill has said the engine incorporates a full authority digital engine control system, known as FADEC, which handles startup, power management, and shutdown automatically. That approach reduces pilot workload and is intended to make the aircraft easier to operate for owners who may be transitioning from piston-engine helicopters or fixed-wing aircraft.

The engine is a key component of the HX50, a five-seat single-engine helicopter designed with private owners in mind. Hill has also announced the HC50, a commercial version certified for training, charter, and utility work. Both aircraft share the same airframe and powerplant, with differences primarily in avionics, interior configuration, and certification standards.

A long road for British turbine development

The last time a British company designed and ran a clean-sheet helicopter turbine engine was in the 1960s, according to Hill Helicopters. Since then, most British-designed rotorcraft have relied on engines developed elsewhere or on derivatives of existing designs. Rolls-Royce, once a dominant force in small turbine engines, exited parts of that market decades ago.

By building its own engine, Hill takes on significant technical and financial risk. Turbine engine development typically costs hundreds of millions of dollars. It requires extensive testing before certification authorities such as the UK Civil Aviation Authority or the European Union Aviation Safety Agency approve the design for commercial use. Hill has funded much of its work through customer deposits, with the company reporting more than 1,000 orders for the HX50 since it opened its order book.

What comes next

The first successful run is only an early milestone. Ahead lies an extensive test campaign that will include endurance runs, performance mapping, altitude testing, and eventual flight testing on the HX50 prototype. Certification typically requires thousands of hours of ground testing before an engine can be approved for use on a production aircraft.

Hill has not announced a firm certification date for the GT50 or the aircraft it powers. The company previously targeted first customer deliveries around 2024 or 2025, though development timelines for new aircraft frequently slip. Executives have said they will prioritize getting the design right over meeting original schedules.

The company plans to build both the airframe and engine at its facility in Staffordshire, England. Hill has said in-house manufacturing gives it more control over quality, supply chain, and cost, though it also requires significant investment in tooling, workforce, and testing infrastructure.

Industry context

The private helicopter market has struggled with high operating costs, complex maintenance requirements, and a shortage of aircraft designed specifically for owner-pilots. Most helicopters certified in recent decades have targeted commercial operators, with private buyers typically choosing between older piston-engine models such as the Robinson R44 or higher-priced turbine helicopters designed for commercial use.

Hill has positioned the HX50 as an alternative aimed squarely at private owners, with an emphasis on cabin comfort, simplified operation, and lower running costs than existing turbine helicopters. Whether the company can deliver on those promises depends heavily on how the GT50 performs through its remaining test program and how quickly Hill can move from a running engine to a certified, production-ready product.

For now, the first run represents a rare piece of good news for British aerospace manufacturing and a tangible step forward for a program that has drawn skepticism from some industry observers who questioned whether a small company could build both its own airframe and engine. The next several months of testing will determine whether that skepticism was warranted.