Picture this: you’re relaxing in your aircraft seat at a cruising altitude of 43,000ft. The friendly cabin crew have just served you a perfectly chilled drink, and you’ve chosen your á la carte dinner. Before you bite into your warm bread roll, think for a moment about the complex engineering that has made your airline dining possible. Every system in the galley where your food is prepared has been designed, and certified, for functionality and safety.
The components of an aircraft galley have to meet a range of requirements that go far beyond those of a domestic kitchen. The basics may sound similar: cooking and heating activities use ovens, microwaves and hot water; ventilation systems circulate fresh air and extract cooking smells; pipes deliver water for drinking and cleaning, and drain away waste; refrigeration and chiller systems keep food and drink cool. Your kitchen at home, however, is unlikely to have to face challenges such as a floor that may flex and move, or be at a 10° climb angle. It’s even less likely that your household kitchen will have to consider the need for ballistic protection, whilst being constructed of lightweight but durable material that will remain intact under impact conditions. All to be considered while servicing up to 300 passengers.
Each component of the galley is designed and built by the manufacturer to meet these difficult challenges. It’s then rigorously tested to ensure that it is functional in a range of conditions, and meets stringent Civil Aviation Authority (CAA) and health and safety requirements.
Creating kinder kitchens
This is where Frazer-Nash comes in. Using our expertise and a range of complex engineering tools, including finite element analysis (FEA) and computational fluid dynamics (CFD), in parallel to vigorous physical testing of the galley components, we can provide the aircraft manufacturer, and airline, with confidence that each and every part will perform safely, fulfilling its designated purpose. Certification of the galley design might range from CFD modelling of the galley ventilation system, to demonstrate that the appropriate airflow is going through compartments; to using FEA to deliver assurance that the galley will retain structural integrity in a crash and not impede passenger and crew evacuation.
The galley doesn’t work in isolation, but is fully-integrated into the aircraft design and systems alongside various other galleys and interior structures. While electrical, coolant, and water supplies will be provided as part of the wider aircraft build, the galley will have to be integrated and fitted into these connections and needs to be precision manufactured to fit to the floor at the exact tie-in locations. Once installed, each element will need to securely match its allocated space creating a consistent interior.
If the galley adjoins to the cockpit, then both ballistics and abuse testing may be needed on the adjoining wall, to demonstrate that it will withstand bullets and weight impact, protecting the flight crew. Abuse testing on some aircraft has included assessing the damage that would be caused by the impact of a heavily-laden trolley run down the plane.
The health and safety of passengers and cabin crew is also a key concern during galley design and certification. The CAA’s Civil Aviation Publication (CAP) 757 stresses the importance of considering crew health and safety in the galley – from preventing burns and trips, to placing regularly-used items at the correct height for access. The comfort and well-being of crew and passengers are therefore a key deliverable, whether through ensuring light levels in the galley are suitable for crew to complete paperwork without keeping passengers awake, or changing a work surface material to prevent reflected glare. Adding side handles on high-level boxes to allow shorter crew to reach and lift them helps prevent manual handling injuries, while turn peg constraints prevent inserts moving during turbulence. Noise and vibration which could adversely affect both crew and passengers – with impacts ranging from emitting a mildly annoying buzz to causing more serious hearing damage – is also considered and solutions tested and certified.
Food for thought
Of course, as a kitchen, the galley equipment must be able to perform its primary function of food preparation. A warm beer or sandwich might simply irritate, resulting in customer dissatisfaction, but more seriously might lead to food poisoning. Refrigerators must keep food cold under all conditions; ovens must heat it through thoroughly to ensure bacteria are killed. Again, analysis and testing can make sure that passenger and crew health is not put at risk. Fluids modelling, for example, ensures that water flows at a specific speed and does not become stagnant in pipes, minimising the risk of Legionella bacteria growth.
The challenge, however, is that there is no standard galley against which a single set of testing criteria can be run. Customers choose more, or fewer, of particular components or layouts to fulfil the requirements of their aircraft operations and passengers. Furthermore, despite a modular standard of design, such as ARINC 810, often an airline will require a bespoke configuration to meet their precise needs. This can make testing more complex, as each system is near-unique. Often, client-specific tests will also be required: if the aircraft is based in the Middle East, for example, which has a higher ambient temperature and humidity, additional testing will be needed to show how the galley works under these conditions.
Finally, today’s aircraft galleys are not only required to be safe and fit for purpose, they also need to look great. Operators use them as a branding tool, with covers designed and used to promote the airline. As more innovative galley solutions are developed and delivered by suppliers there is no doubt that the complexity of galley systems’ engineering will increase to meet operators’ needs. So as you eat your next in-flight meal, stop for a moment to think of the engineering that goes in to delivering your dinner.