Aviation Week's 2023 Fleet and MRO Forecast predicts that commercial MRO demand in the UK will represent a value of $28.5 billion for the period 2023-32. 

Engine maintenance work has the highest share of 39%, around $11 billion of the total MRO demand in the country. Line maintenance and components account for 23% and 21% respectively, while modifications and airframe heavy will see demand of around $3 billion and $1 billion, respectively. 

Source: Aviation week Intelligence Network Commercial Aviation 2023 Fleet and MRO Forecast.