Full lifecycle assessments are becoming increasingly important in a variety of industries, and aviation is no different, with a growing focus on the recycling, reuse and revalorisation of aircraft and their components.
Canadian airline Air Transat recently recycled eight of its oldest aircraft, Airbus A310s, most of which date back to the early 1990s. Keith Lawless, the airline’s senior director for environment, emissions trading schemes, and strategic projects, explains that the usable life of a modern jet aircraft is “25-30 years, although the recent tendency is to retire aircraft earlier in order to get more fuel efficient airplanes. The key driver for retirement is the cost of engine overhauls, especially for the big turbofans.”
“Engine overhauls,” Lawless says, “may become so expensive that airlines prefer to retire the aircraft rather than pay for the shop visit.”
When it comes to end-of-life, Lawless estimates that Air Transat is typically able to reuse or recycle approximately 87-90% of an aircraft by weight, noting that the non-recyclable landfill is composites, insulation and interior plastic panels. These either require specific techniques and equipment or are not yet recyclable. Aircraft recycler Tarmac Aerosave, meanwhile, cites a 92% figure for recycling, while Vallair cites “recycling and recovery” as more than 94% [PDF].
Within that number, between a quarter and a third of the aircraft’s weight can be reused, primarily engines and components. The end-of-life recycling, reuse and revalorisation of these is accounted separately, but it is estimated to be high, with Lawless noting that the alloy content of engines is significant and high-value, but that there is a substantial energy impact on remelting and reprocessing of alloys.
Taking the 87% figure as a starting point, recyclables break down to some 57% of the aircraft, while reuse makes up 29% and valorisation 1%, with the remaining 13% ending up as landfill. This latter proportion will often be contracted out by a specialist waste management company, and separated out into a series of categories, which can include glass, plastics/composites, scrap metal, pneumatic material, fuel/oils, electronics, asbestos and anything radioactive [PDF, p10].
When it comes to new technologies, particularly the newer generation of carbon fibre aircraft like the Boeing 787 and Airbus A350, Lawless’ recycling prognosis is “not good. It is virtually impossible to commercially recycle carbon fibre at the present time. This is an especially big problem for the B787 where the fuselage is made entirely of carbon fibre. No-one is sure what will happen when they retire in a couple of decades. Everyone is crossing their fingers and hoping that a solution will be found. This is why it is important to design products with a lifecycle mindset.”
Airframers have made some steps towards reducing carbon-fibre waste, but this is largely taking offcuts and unused material to make other items in that same material. Boeing, for example, is recycling excess composite material to make laptop cases and car parts, while Airbus’ material is making bicycles. Boeing’s partner in that initiative, then known as ELG and now as Gen 2 Carbon, has been working on a closed-loop system, but more work is clearly needed, with early versions of these aircraft now a full halfway through their expected useful lives.
Lawless highlights Bombardier’s work on its C Series — now the Airbus A220 — in designing for a full lifecycle, including publishing Environmental Product Declarations for both the CS100 and CS300, now the A220-100 and A220-300. An EPD is a transparent information document that is third-party assessed and externally verified, summarising the lifecycle assessment of the product under the framework of the ISO 14025 standard.
Further standards development is ongoing under the auspices of AFRA, the Aircraft Fleet Recycling Association, with its BMP (Best Management Practice for Management of Used Aircraft Parts and Assemblies and for Recycling of Aircraft Materials) the industry’s primary toolkit. Extending and developing this work — including via a transparent and rigorous carbon accounting framework — will be critical as the industry seeks to improve its environmental credentials.
Author: John Walton
Published: 1st March 2022
Photo by Jason Rosewell on Unsplashv
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