Cabin Enhancements and the Role of Advanced Material Implementation in Structural Development
The number of flights and passengers are in an uptrend. The International Air Transport Association (IATA) announced that global demand (revenue passenger kilometer or RPK) in April 2019 increased by 4.3% compared to April 2018. Global capacity (available seat kilometer or ASK), increased by 3.6% and global load factor, 0.6% to 82.2% over the same period. This demand growth requires airlines to adapt dynamically to differentiate in the market. As airlines strategically add capacity, they must do so with an eye on efficiency and laser focus on revenue per available seat mile (RASM).
It is not easy…
There are many examples of airline bankruptcy and mergers, such as Delta Airlines and Northwest Airlines in 2009, not to mention Low-Cost-Carrier (LCC) trends that continue to dominate the battlefield. To compete, airlines must manage an efficient supply chain, suppress operational costs, expand their network, employ an effective overbooking strategy, and adjust pricing and schedules continuously.
So, how are airlines remaining competitive, holding onto profitability, and getting the attention of the consumer at the same time?
One of the strategies for an airline to win in the market is to create product differentiation through cabin features that improve the travel experience. One of the primary trends in cabin enhancement is the availability of inflight connectivity. Passengers want connectivity not only on the ground but also in the air. Two of three passengers are willing to rebook a flight if inflight Wi-Fi is available. Further, a large number of passengers (54%) would prefer to watch digital content on a seat-back device rather than their personal device (36%). Customer demand for connectivity and entertainment experiences, including hotel in-flight notification and cargo tracking, means that airlines and aircraft manufacturers will compete for differentiation in this arena.
Another trend is creating an affordable increase in “comfort”, such as increased legroom, knee-room, headrest, and seat flexibility. Because the lifecycle of interior programs is shortening, airlines are revisiting the cabin structure more frequently, making progressive changes in three to five-year spans. The shorter upgrade cycle gives airlines a chance to experiment with middle-seat elimination, extra seat width, and space for increased baggage allowance. In doing so, airlines are deploying branding and marketing initiatives to test how much travelers are willing to pay for extra comfort and technology. On long haul flights, we see sleeping compartments and hotel-like products hitting the market. Airlines will continue to offer more comfort features, creating product differentiation and building a brand culture around the offerings.
The top examples of success in cabin development today, according to SKYTRAX Rank (2018), are Singapore Airlines, Qatar Airways, and Nippon Airways, as voted by travelers around the world. These airlines offer updated cabin structures with flexible seat adjustment, a wide variety of customizable in-flight meals and drinks, inflight entertainment, and internet and cellular connection as "standard" facilities. These facilities illustrate the airlines' effort to fulfill the passenger needs on short and medium flights. In a higher class, they offer amenity kits, a high-quality headset, exclusive seats, and even private suites with double beds. Aircraft with higher-class seat configuration usually fly long-haul where the passenger demands more comfort and entertainment. These additional facilities require airlines to operate more efficiently, especially on weight strategy.
"Airlines are improving the customer experience to differentiate themselves, starting with upgrades to the galley and laboratory, as well as setting marketing initiatives to promote their existing fleet of varied aircraft. There is a trend away from 'class' and a move toward a more extensive array of products within an aircraft to satisfy more customers." - Mark Fuller, Stratasys
New facilities in the cabin can add cost to the airline because of the extra weight for the additional equipment, thus decreasing RASM. That is why the use of advanced materials in cabin development is critical. Engineering innovations through advanced materials with higher strength-to-weight ratios allow airlines to utilize more space in the cabin and keep seat weight low. Lightweight materials translate into more spacious seats, extra baggage storage, and the ability to add inflight entertainment equipment.
Additionally, materials and structures require fewer modifications, reducing maintenance and operational costs, while delivering a better passenger experience. Interior structures are less complicated compared to airframe parts, but structures must still meet stringent requirements for safety.
The following list explains some of the composite types in an aircraft.
1.Fiber-reinforced polymer resins
The fibers are usually carbon or glass that are impregnated with resin (prepreg). Prepregs are placed in molds and then cured at high temperature and pressure at a certain time in an autoclave. This manufacturing process is called lay-up. Lay-up methods provide wide flexibility in a variety of forms, making the cabin look aesthetic and modern. On a simple form of structure like arm rest and tray table, it is convenient to be manufactured by compression molding methods. Zodiac Aerospace L3 seat weighs below 4kg with this manufacturing method.
2. Sandwich Panel
The Sandwich is named after its obvious structure composition. The lightweight core between thin face sheets increases the panel stiffness enormously. Sandwich panels are more cost-effective than skin composite and can be cured with the skin easily. More complex shapes such as luggage bins are made from flat pressed with simple “cut and fold” methods where a strip is removed to expose the core and is then folded to the specified form. This kind of composite has been used mainly in flooring, ceilings, galley walls, lavatories, and cargo hold liners. The pressure while forming sandwich panels has been shown to influence flexural strength, impact strength, and compressive strength.
Additive manufacturing techniques such as selective laser melting (SLM), a type of 3D printing where the consecutive addition of materials in ultra-thin layers enables builds not previously possible, such as the production of individually shaped parts and small batch sizes. Also, addictive manufacturing uses 5% of the raw materials that the conventionally manufactured part mills.
Advanced materials used in combination with generative design and 3D printing has the power to create complex parts that are substantially lighter, but also stronger. A revolutionary technology is being used by Airbus to build the world’s largest metal 3D printed airplane component called the Bionic Partition, which is the dividing wall between the seating area and galley. The process imitates nature’s evolutionary approach to evolve thousands of designs. Starting with the design goal, then using cloud computing, generative-design software explores all possible permutations of a model. The generative-design algorithms emulate growth patterns in nature: slime mold and mammal bones. The final result of the generated structure is optimized to be durable, light, and utilize the least material to build. This complex structure is nearly impossible to replicate in conventional methods. The optimized design of these builds allows for parts to achieve higher strength-to-weight ratios and improve fuel efficiencies. The Bionic Partition is 50% lighter than current partitions, lowering fuel consumption and cutting carbon emission.
Advanced material application in the aircraft, especially in the cabin will continue to rise as airlines seek to create more spacious cabin configurations and reduce weight at the same time. For fuel saving purposes, Airbus states that one kilogram (2.2 pound) in weight reduction will reduce jet fuel consumption of 106kg (233.2lb) a year, thus potentially cutting a significant amount of CO2 emission. It is also lowering the operational cost hence make air transport is affordable for everyone. Advanced material implementation also supports cabin development to create a more significant margin for the cabin interior and equipment updates in the future.