A Healthy Balance
A helicopter’s EMS interior effectively has to turn the aircraft into a flying ambulance, able to match the medical capabilities of its road-going equivalent, while adhering to stringent weight and space restrictions. Emma Kelly talks to interiors specialists to discover how they meet the ever-evolving needs of aeromedical operators.
Designers and suppliers of emergency medical service interiors are having to be increasingly creative as they undertake a balancing act in order to meet weight requirements while fulfilling the operators’ need for additional medical equipment on board EMS helicopters. The extensive use of lightweight materials, including aluminium and composites, along with clever design are the basis for getting the right mix. More and more medical devices and pieces of equipment are seen as vital and becoming standard on EMS helicopters, but they bring additional weight. “Standard devices are a defibrillator, a ventilator, IV pumps. It seems like these are standard for everybody now where that wasn’t necessarily the case a few years ago,” says Matthew Christenson, vice-president and account executive at Spectrum Aeromed. Fargo, North Dakota-based Spectrum specialises in EMS interior design and certification for both fixed- and rotary-wing aircraft for customers worldwide. “Then operators are looking at whether they can have an ECMO [extracorporeal membrane oxygenation] unit, whether there is room for a balloon pump or, if they are doing infant transport, an infant incubator,” continues Christenson. “They are using all of these devices, monitors and ventilators, and somehow you have to accommodate them, secure them and power them to operate during flight.”
Making Light Work
But while such medical devices are aiding EMS crews in their job, they are not making it easy for interior designers to incorporate all of the desired equipment within a platform’s weight limits. At the same time, EMS operators are also having to deal with a population that is increasing in size and weight, with crews often having to treat and transport bariatric patients. “On every programme, we are focused on how to maintain lightweight applications,” says Christenson. The company uses aluminium in a lot of applications and composites to protect the interior, for valances, for example, and in cabinetry. “The engineers have to get creative in how they utilise the proper materials and get the structure to work for an application.” “It’s always a difficult conversation. We need a light interior, so the aircraft performs properly, but we also need solid, very usable equipment that lasts for the time they are going to operate that aircraft.” UK company Specialist Aviation Services agrees. “With new developments in technology and design, and increasing demand for improved performance at reduced costs, locating and utilising the most efficient, lightweight parts is more important than ever,” says James Kingdon, its head of design. “However, utilising lightweight materials in certain applications can come with its own set of challenges. For example, design engineers working on aircraft interior applications must replace traditional materials with lightweight materials without sacrificing quality or end-user comfort. It’s really important to ensure maintenance personnel are not lost in the design phase, as this can be easily overlooked,” he notes. Air medical equipment solution specialist LifePort, which has experience in virtually every helicopter type, is increasingly being asked for lighter solutions. “Although we have manufactured EMS interiors for over 32 years, we are now being asked to either develop brand new interiors that are lighter weight or reduce the weight of existing interiors that function well to give the aircraft more performance and range,” reports Frank Graham, LifePort’s vice-president of sales and business development. For example, the company is currently in the closing stage of US FAA STC approval for a lighter weight EMS interior for the Airbus H130 B4.
Built to Last
Most recently, Spectrum’s designers have been putting their creativity to use on a new AW119 interior that includes a 10-litre liquid oxygen (LOX) supply, a patient pivot loading system from the left side, one aft-facing and two forward-facing medical attendant seats, medical mounting options on the ceiling and back wall, and valance panels for all radios, controls and outlets. “It has a lot of new designs, and it’s incorporating that creativity addressing where we put devices and utilising the interior to the max,” says Christenson. Next up is an upgrade featuring LOX for the Bell 407. But going lightweight also brings challenges. “There are two sides to it. You are always trying to go lighter, but what you risk if you go too light is that you are going to have equipment that’s not going to last. You want to have a design that can take the day-to-day heavy requirements and be lightweight,” he emphasises. As aircraft get loaded with more medical equipment, the accompanying increase in weight compromises the performance, Graham acknowledges. “Operators are asking us to re-evaluate existing products to identify areas in which we can further reduce weight or, in the case of the H130 B4, design some new products that are lighter than the product or feature being replaced. This is an area LifePort excels in, as we have invested heavily in new manufacturing capabilities that we have vertically integrated into the company,” he explains. LifePort recently opened a state-of-the-art composites facility which includes a clean room, a five-axis CNC router for mould fabrication and an autoclave to finish structural and non-structural parts. The company also has the LifePort Machining Center, so “we can manufacture the parts in-house, evaluate them as they come off the machine and ultimately structurally pull-test them at our in-house testing centre. These capabilities and investments allow us to tackle the critical weight issue head-on,” he notes.
LifePort isn’t alone in establishing such in-house capabilities, with European EMS interior supplier Aerolite previously acquiring German company HS-Composite, now Aerolite Composite, to secure composite fibre technology and expertise. Graham says LifePort’s in-house capabilities give it an advantage in creating lightweight solutions. “It starts with engineering, then manufacturing with alternative materials and testing the products immediately to save time and make adjustments. “Very few companies can design, engineer, fabricate, test and revise a solution in a single facility. The time saving, the speed to market and the weight reductions are optimised and done so quickly and safely without compromising structural integrity and functionality.” The fact that its EMS interiors are modular in design and manufactured to high standards contributes to LifePort’s success in the sector, Graham believes. “We recognised 30 years ago that the product has to be able to take the daily usage of an EMS operation and last. In the air medical space, aircraft can’t be grounded because the interior has an issue.” He also points out that LifePort has its own FAA repair station and offers 24/7 support. The company has developed numerous speciality litters to accommodate medical equipment including incubators, balloon pumps and ventricular assist devices, and is working on a raft of new developments. “We are not only working on new mounts, cabinets and loading systems, but we are also working on new airframes, new litter types, alternative manufacturing and anything that makes the product better and lighter weight. “Lightweight solutions are achieved by better engineering and design, optimising how much weight you can remove from a part while maintaining structural integrity and using alternative materials like composites, carbon fibre and exotic materials like titanium,” he explains. Other materials hold considerable promise for the future, including “some that we will not disclose for competitive reasons”, says Graham.
Likewise, fellow EMS interior specialist AMS Heli Design is exploring new materials to deliver additional weight savings. “We are starting to use a new alloy that allows 37% less weight compared to similar aluminium and composite materials that also allow significant weight savings,” says its CEO, Andrea Girolin, who declines to elaborate further on materials. Girolin states that AMS is well known for bringing innovation and composite materials to the cabin, “resulting in outstanding lightweight solutions with the latest technology features available”. The company primarily works on Leonardo AW109s and AW119s, and it is the only supplier with a certified EMS interior for the AW109S Trekker. AMS’s goal is to achieve weight savings with its interiors through the design and use of composite materials, he says. For example, it recently delivered an AW109SP with a new EMS interior that is 150 lb lighter than the previous one installed, while its AW119 interior is 103 lb lighter than the best competitor interior, according to Girolin. “That’s game-changing for the helicopter’s performance and capabilities.”
Thanks to technology developments and finite element analysis, strength and usability are not compromised with new lightweight designs. “Our new Trekker interior has been in service a year, and it has been flawless since,” he reports. Recent developments by AMS include the certification of a new high-performance medical air pump that works on DC current and is capable of supplying up to 40 lpm at 50 psi with hardly any vibration or noise, says Girolin. “Often customers need two or even three pumps to meet their flow demand, while our product can make it a single, lightweight unit,” he explains. In addition, the company has certified a new medical rack and storage box for the AW109SP and Trekker. AMS also collaborates with German company Autoflug Group, developing customised lightweight interior solutions for different sectors including a lightweight seat, the Flyweight.