We at Hill set ourselves an epic challenge, to build the finest five-seater helicopter ever, which in turn needed the most cost-effective light turbine engine ever. To do this we’ve had to vertically integrate an entire aerospace supply chain and unroll production in a huge custom-designed manufacturing facility. With all aspects of the HX50 programme delivering on time, on target, we are looking forward with optimism to all that we hope to achieve in 2025.

Major Milestones

Work is progressing with the rotor blades, the skid mounting, flight controls and windscreens. These include testing of the starter generator, the avionics PFD user interface, the electrical system, the crashworthy seat and also the drivetrain.  

Production Centre 1 has been equipped and set up for production in only nine months. It’s impressive by anyone’s standards, but particularly in terms of the wonderful setting it provides for the team who are now conveniently situated under one roof, and also for customers, who can see for themselves how quickly the project is advancing. 

The high quality inherent in the HX50 helicopter itself is amply reflected in PC1’s clean, futuristic surroundings.

It has been fascinating to see the blueprint of the building come to life, and a reminder of what a huge undertaking the project is, not just turning out a new helicopter from the ground up but installing and building all the infrastructure needed for the task. This has involved an incredible amount of planning and sheer hard work – it is tremendously rewarding to see it all unfold according to plan.

The layout of our end-to-end composites manufacturing facility is designed to accommodate the way material flows around the facility, and includes:

• storage area
• trim shop
• gantry mill and associated dust extraction system
• laminating clean room
• composite curing oven
• paint facility

We have all the space we need in PC1 for high volume composite production for the Gen2 fuselage, and this has meant investing in a lot of new machinery, including:

• our first CNC cutting machine which replaces the laborious hand templating and trimming of individual layers of carbon fibre that needed to be painstakingly built up and laid really carefully into each mould to make every element of the structure, with an automated process.
• laser ply placement technology which allows the projection of laser guideline shapes that tell each laminator exactly where to place each of the CNC kit-cut elements into the mould.
• technology that provides a step-by-step digital record of every stage of the laminating and manufacturing process, ensuring that each structural part is made perfectly every time.

We purposely created a vast space, designed to turn out highly controlled, high quality aerospace composite structures, so that we can lay out all the tools and fixtures necessary to produce the entire HX50 airframe in parallel, and have multiple teams of laminators working on these to hit the production rates we need.

And there’s more ...

• precision machine shop
• new production control system
• laser alignment of CNC machines
• recalibration of our metrology
• new mill-turning machine that allows us to produce complex multi-axis components from billet to finished component in a single operation
• new EDM machine that allows us to put fine hole details and all of the cooling hole details into our in-house cast turbine blades

GT50 Engine

For decades, one of the greatest concerns of pilots to owning a turbine engine helicopter has been the risk of an over temp on startup, causing huge amounts of damage to the engine. HX50 comes with a duel FADEC engine control system that simplifies all of that.

The starter procedure is simple: turn the master battery on, turn the avionics on, the avionics will come to life, and then simply press the Start button and the engine will bring the whole system to life.

The engine team and our controls team have been working tirelessly to develop every element of the control system that runs the fuel management, the starter generator, to bring GT50 to life and to maintain stable combustion and relight, if required, during the entire operating envelope of HX50.

In addition, some of the ancillary systems have now been added to the accessories module:

• lubrication system hardware
• key sensor elements for the control and instrumentation system
• Hall effect sensors used to pick up the N2 speed  
• Hall effect sensors that pick up torque by looking at the distortion of the drivetrain  throughout the engine
• engine mounts both at the rear and the front end of the engine to secure GT50 to HX50

Let’s take a more detailed look at the advanced technology work that is going on at PC1 in the new Precision Laser Welding Facility, where the specific task of taking the individual rolled rings of the annular combustor, assembling them in a welding fixture, and then creating perfectly repeatable gas tight welds between each of the layers of the rings that make up the film-cooled combustion sheeting, is being conducted.

These processes are traditionally extremely labour-intensive so we’ve been focusing very much on how to jig and fixture these components so that we can subsequently automate them and eliminate the labour content, making the GT50 combustion system as cost-effective as possible.

One seemingly innocuous part of the GT50 engine that’s crucial to the performance, efficiency, emissions and reliability of the engine is the fuel injection nozzles which underwent a series of tests on our laser visualisation rig.

All this comes together on the test rig where we are tuning the critical internal functions of the FADEC system, that allows us to stably ignite the flame and control the engine as we ramp up to higher loads and then back down to lower loads, and to do automatic re-ignition if for any reason the flame flames out during operational conditions.

The PC1 engineering stores hold a huge array of components ready for the second major module of the GT50 engine that’s ready for test, the drivetrain module.

All the shaft and mounting components and bearings have been assembled onto our speed reduction test rig which allows us to drive two gearboxes back-to-back, using an external drive motor in order to operate the gearboxes throughout their entire operating envelope.

This will allow us to verify the performance of the gear drivetrain itself, of the lubrication system, and of the general reliability and performance and efficiency of all elements of the system, enabling us in turn to clear them for flight testing.

Airframe Development

Among the crown jewels of any helicopter company is the rotor blades and the associated technology. Our highly optimised aerodynamic design is responsible for HX50’s high cruise speed, but with high cruise speed in any helicopter comes the risk of unacceptably high vibration. - Jason

Over the last 9 months or so we’ve been working extensively to optimise the dynamic design of HX50’s rotor, cabin design suspension, gearbox mounting system, and the overall structural dynamics of the airframe itself.

We’ve been using modern finite element analysis to optimise the structural stiffness, mass distribution, and general aero-elastic design of each HX50 rotor blade, ensuring that all the natural modes of vibration are placed as far away from exciting frequencies as we possibly can.

We’ve taken a very bold move to minimise the amount of vibration that can be transmitted down to the fuselage, making HX50 the smoothest 5-seat helicopter in its class. - Jason

Elements of the rotor blades for elemental testing are now being produced before we make full rotor blades for full scale testing.

Attentive to our customers’ comfort and concerns

Some of our pilot/customers who are advocates of skids, and were able to try out the HX50 cabin in person, noted that the forward skid leg obscured quite a significant proportion of the cabin door opening, limiting the ease with which you can get into and out of the cabin.

We decided to shuffle the whole skid mounting point forward slightly and also to reduce the cord of the skid pan aerofoil profile, and shrink the track of the skids, reducing both the drag and the weight, thus making a better all round skid design, and making sure the unit will fit inside a shipping container.

We’ve made a subtle modification to the pivot point underneath the cabin floor, bringing it slightly further aft. This allows us to use a common axis for both the pilot and the co-pilot’s flight control without the stick head for the co-pilot blocking his entry and egress into the cabin.

The stick head design has been updated and the friction system added, making the cyclic mechanism significantly simpler, lighter and stiffer, leading to an improvement in flight dynamics characteristics.

The last of the flight controls to be developed is the fully adjustable pilot and co-pilot pedals, for which we are currently trading off two versions.

It’s generally acknowledged that helicopter seats are in fact instruments of torture, and I’m absolutely determined for that not to be the case for HX50. - Jason

They don’t have to be! Over the last 6 to 12 months we have completed extensive comfort trials and integrated all practical customer feedback. We have now improved comfort surfaces and milled them in several grades of airworthy carbon-laced foam. The isolated energy absorber tests have been completed, so next come the final stages of comfort trials before freezing the crew seat around the existing mechanical design that has now been frozen. We’ll be able to release the seat for production, prototyping and then testing early in Q1 in 2025.



Our all new glazing production facility has been specifically developed to produce vacuum formed and drape formed transparent panels for impact and non-impact resistant windows across the platform.

In order to produce optically perfect windows for HX50, we’ve developed a new approach to tooling, both for poly-carbon and acrylic, including new ways of fixturing and holding the hot flexible material down on to the tool during the forming process.

We will soon be trialling these methods to demonstrate the capability of the newly developed process.

Digital Cockpit

Another important milestone in the development of HX50 has been reached - we’ve now frozen the primary flight display design for the digital cockpit.

The design itself has gone through numerous iterations over the last two and a half years, gradually evolving from piloted flight tests, customer feedback and a consistent pursuit of perfection in terms of combining the best elements of traditional analogue gauges with all of the benefits of modern digital displays. The production version of the PFD is crisper, cleaner, and more refined than ever before. It features:

• air speed indicator now conveniently positioned at the top of the display with a simple, curved arc giving a needle as well as a digital display
• new and novel altitude indicator that uses one needle to present your altitude, irrespective of how high you are above sea level
• large, easy to read vertical speed indicator  
• large power indicator that’s always been a primary feature of the Hill digital cockpit
• rotor and engine tachometer that are now crisper, clearer and easier to read
• engine temperature and electrical gauges provided at the bottom of the screen
• homogenised communication and transponder bar

As in previous designs, we’ve also got the pass-through layer that provides video footage as a background from the camera installed in the nose light in the front of the aircraft. Colour schemes have all been adjusted to work accordingly, as has the toned-down night theme that makes the contrast more appropriate for night flying so as not to glare in low light environments. We’ve also integrated with that the infrared pass-through layer to make flying at night safer than ever before. Many of these refinements are a direct result of interacting with our customers.

In the new avionics laboratory Eric and his team are implementing the production variant of the primary flight display for the digital cockpit on target hardware, starting with the PFD to then move on to the IPI and the MFD.

The next stage is to connect up to all the peripheral devices such as the GPS source, transponder, com radio, audio panel; get those integrated with the production wiring loom, switches, hardware, circuit breakers; get the whole system working and laid out on the pegboard prior to being transplanted onto the first flying HX50.