Mike Richardson hears from Hill Helicopters and why the company chose to invest in Okuma’s range of CNC machine tools supplied by UK agents, NCMT for the precision machining of its engine compressors.

Hill Helicopter’s founder, chairman and chief engineer, Jason Hill says he has always been fascinated by helicopters, particularly the freedom and the access to the lifestyle they offer. He is exactly the kind of person who should be buying a helicopter, but in his eyes there isn’t really anything on the market that meets his needs in terms of recreational flying. This is why his company is building the HX50 helicopter.

Hill Helicopters is the first truly private luxury helicopter manufacturer based in the UK. Jason is a firm believer in the importance of manufacturing parts in-house. Traditionally, aircraft manufacturers have subcontracted much of the high-value components out to the aerospace supply chain. However, the costs can often ratchet up. Hill Helicopters uses a traditional model of what Jason describes as vertical integration, so if it is an expensive or important part of the helicopter, then it is made in-house at Hill Helicopters.

Vertical integration within the aerospace industry is a simple idea: purchase the highest quality raw materials, add the maximum value to those materials in-house and then ship premium products out of the factory. Every business must go on its journey to get to this point.

Over the last few months, Hill Helicopters has procured the necessary equipment required in terms of CNC machines, its composite materials manufacturing capability, its metrology equipment, and its castings facility to do everything in-house. The first wave of Hill Helicopters equipment has been installed, commissioned and as of now, can produce precision aerospace-grade components to the highest standards faster and at the lowest possible price point. It really forms the template for everything Hill Helicopters is doing across the entire helicopter programme.

A precision decision

According to Jason, it has never been easier to make precision parts with relatively small amounts of capital expenditure. Modern CNC machinery enables companies like Hill Helicopters to make precision-machined components with a very small number of flexible machine tools that can scale very well – and these same machine tools can produce much of the tooling needed to make low-cost composite pattern & mould tooling too.

Pretty much everything required to make an aircraft, such as a composite fuselage, a rotor system - and even a gas turbine engine, can be done with modern CNC machinery. Hill Helicopters’ development centre – a smaller version of what will be in its full production facility - brings all of this capability in-house. The company has invested in its people, its machinery - and in ensuring it has the knowledge to produce precision aerospace parts. In a nutshell, this underpins the company’s take on vertical integration for helicopter production.

“We perform in-house manufacturing of what will probably end up being the single most expensive part of our GT50 gas turbine engine that powers the helicopter,” Jason begins. “The compressor is an extremely challenging component to manufacture. It is incredibly ‘5-axis’ in that it is curved in every direction! We manufacture the thicknesses of the blades to very thin wall dimensions, plus there are tiny radii on the leading edges and tip clearances between the blades. The shrouds that the compressor sits in are tiny and are important to overall performance. The quality of surface finish is also key, and because it operates at close to 400ËšC, the high grade titanium we use can be very difficult to machine.

“Combine all these factors and it ends up being the most expensive part of the engine. Manufacturing this part in-house allows us to make it as cost-effectively as possible. In addition, it gives us complete flexibility as we go through prototyping and development to make small design changes as we see fit - without having to contact a subcontract supplier and renegotiate another round of new developments. So, it is vital that we can make these parts ourselves.”

A perfect balance

NCMT recently exhibited Hill Helicopters’ HX50 turbine compressor wheel at the Southern Manufacturing and Electronics show held in Farnborough as part of a competition on its stand. As the UK agent for Japanese CNC machine tool builder Okuma, NCMT was chosen by Hill Helicopters as its equipment supplier for the manufacture of components currently being produced on the Okuma CNC machines at its facility - in particular, an Okuma GENOS 460V-5AX 5-axis vertical machining centre.

“The Okuma GENOS range sits within a niche where they are very high quality machines, they are proven, have a great reputation in the aerospace sector, are very accurate and they are reliable in terms of delivering what we need,” explains Jason. “They are also cost-effective enough that when we put these machines to work - and they are producing compressors across two shifts every day - the contribution of the capital and the running costs of the machines to that part price is as efficient as it can be. These machines provide a perfect balance for a precision aerospace application at quality and cost.

“We need to deliver a helicopter at the same price as a supercar, so the capital cost of our equipment against the performance it delivers - plus the machine tools’ productivity, is really important and very sensitive to us. Working with NCMT has been great. When we started with three empty factories, we needed to develop all the capabilities required to build all the parts of the helicopter engine, the gearboxes, and the drive train from scratch. It was vital to have the support of a very experienced partner in NCMT, a company that is completely up to speed, took onboard the real requirements, was able to point us in the right direction of the correct equipment in the range – and reassure us that this was the right combination between price point and performance for our application. Beyond that, the installation, support, and the after-sales care has been brilliant. We have brought our own capability in the company up to the level where it is today - and where we can produce these aerospace-grade components daily.

“So, I would recommend NCMT to anyone. The goal that we are now working to is complete a first flight by the end of 2023 and then into production by the end of the following year. We’re going through planning permission for a factory large enough to support the incredible demand we have created for the product and there is still a great deal of engineering left to do. These are the targets we are currently aiming for and thanks to NCMT’s help, we are on track.”

Proof, if proof were needed, that the true spirit of collaboration will always lead to truly inspired innovation.         

www.hillhelicopters.com

www.ncmt.co.uk