major concern when considering the recycling of aircraft steel because it cannot safely be introduced into repurposed steels. Though plastics have often not been recyclable due to flame retardant chemical use, new methods are being developed to recycle these plastics effectively. Allred and Salas (2005) conducted research in 2005 on a catalytic conversion process at low temperatures to convert rubber, thermosets, and thermoplastics into usable hydrocarbon byproducts. This process was shown to reduce hazardous substance presence by 80%. Other inorganic residues such as heavy metals and oxides can be re-melted to eliminate their toxicity. For large metal components that constitute the body of the aircraft, shredding is required before the resulting metal scraps can be introduced into melting stock. Carbon fibers are among the most common non-metal materials recycled from aircraft. Recycled carbon fibers do not experience any mechanical degradation and can consequently be reinforced into plastics, polymers, or glass to form composite materials. Recycled fiber can be cut to specified lengths before being integrated into these materials: providing a large amount of flexibility in meeting reuse specifications. An airliner can be dismantled in 1,500-2,000 parts (1,000 or so LRUs) in 30–60 days including engines, landing gear, auxiliary power units and components but it can be parked a year or two to maximize the part harvesting. A metal aircraft can be recycled for up to 85-90% by mass, and can be maintained for composite airframes as the industry adapts with a growing carbon fiber market. Storage The aircraft lessor Avolon counted a total of 2,100 aircraft in storage during 2017. Of these, 48% were deemed unsuitable for future flight: making them viable candidates for aircraft recycling. Aircraft that have been parked for three years have a 50% likelihood of being redeployed for flight, and a 20% likelihood after five years of storage. Even though the global jet transport statistics are expected to double over the next 20 years with 43,000 new deliveries and 16,000 retirements projected through 2037, the total count of aircraft in storage is expected to remain constant during this time. The peak of airplane retirement occurred in 2013 with a total of 700 retirements. Strong demand for aircraft from 2013-2016 caused annual retirement to decrease to roughly 500 retirements. Decommissions were totaled at 505 retirements in 2018, increased to 2,200 aircraft in 2020, and were totaled at 3,900 aircraft in 2022 by the Jefferies company forecast. Recycling