It is estimated that for every kilogram of weight saved on a commercial aircraft, 25 tonnes of CO2 emissions are prevented during its lifetime. This startling truth is why weight reduction is considered the Holy Grail of aerospace engineering, and it is why companies like Airbus invest considerably in the area.
A kilogram of weight might not sound much, but commercial aircraft are built to last more or less indefinitely. Jets remain in service for around 25 years. It is estimated 1kg of weight generates 1 tonne of CO2 a year. The potential to reduce emissions through weight reduction is therefore enormous - and it is why most commercial airliners have a handhold luggage weight allowance for each passenger.
A remarkable journey
Flying in itself is quite remarkable. Commercial aircraft typically fly between 31,000 and 38,000 feet. It only takes a commercial aircraft around 10 minutes to reach cruising altitude, at which stage the pilot can turn off the seatbelt lights and you can stroll over to the toilet – at a speed of around 575mph.
This is something we take for granted whenever we fly, and the engineering that makes it happen is taken for granted even more so. Most people give little thought to the weight of an aircraft and how it can affect airspeed, cruising altitude and emissions. For companies like Airbus, the weight of an aircraft is a top priority because it directly effects aircraft value and service. Here, engineers can bring real value to the table.
A more efficient plane is a more desirable plane, especially in today’s world where talks of a ‘climate crisis’ are rife (and warranted). But this is about more than business and the environment. It’s about making sure air travel is as efficient and clean as possible. Carbon neutrality is a long way away, but the aviation industry is making tracks in areas of applied and practical engineering. One of these areas is 3D printing.
3D printing in aerospace
We’re going to keep things really simple with how Airbus is using 3D printing to reduce aircraft emissions - they are using it to replace parts on existing aircraft models with lighter 3D-printed versions. In other words, they are printing like-for-like parts in appearance which are lighter than the original - sometimes by over 70%.
The average Airbus is hitting is parts that weigh 55% less than the original with a 90% reduction in raw material use. Because additive manufacturing results in very little waste - and what waste it does produce can be recycled and repurposed - it is also a more carbon friendly manufacturing process than machining.
Airbus make use of the 3DGence Industry F340 to fabricate part prototypes. For these parts, they utilise PEEK, a high-temp material suitable to end-use application. MB Aerospace work with Airbus to make these custom components.
Importantly, the parts created with additive manufacturing are suitable for use in real aerospace application.
On this, Sebastian Pietruszewski, Key Account Manager at 3DGence, says: “Printer manufacturers have been closely observing the needs of the industry to propose customised solutions to cater for the growing needs of users. 3D print supports production because it enables faster and cheaper manufacture of machine components, spare parts or finished small-series products with no material losses and practically of any shapes.”
“More importantly, the items are also more durable. The best printers are featured with a number of replaceable heads suited to the filament type. The new and more robust material does not require changing the whole printer but only buying an additional head. The solution is quick and easy to implement.”
Following the introduction of a 3D printing workflow, the Airbus engineering department used it to create a small-sized pilotless aircraft named THOR. This allowed them to test the accuracy of the technology and print true-to-design parts.
The first THOR plane weighed 21kg and could fit into a 4 x 4 metre square. Powered by a 1.5 Kw electric propeller system, it had a 90% 3D printed body. The aircraft didn’t represent a production model Airbus will make, but it did put 3D printed aircraft parts up in the sky, proving beyond doubt their functional value.
In 2017, Airbus installed a 3D printed titanium bracket for the first time in serial production of the A350 XWB, and they are planning to use 3D printed metal brackets and venting pipes in future models too.
Here's the titanium part in question:
Airbus sees 3D printing as playing an essential role in the future of aerospace. “In addition to its potential for decarbonisation, 3D printing is an essential technology for the digitalisation of industry. One of the advantages is that new parts can be virtually designed, printed on site and then tested – all in a very short time span,” notes Airbus.
3D printer: 3DGence F340