In Civil Aerospace, large engine flying hours continued to recover and were 65% of 2019 levels in the four months to the end of October and 62% year to date. The 36% growth year to date compared to the prior year reflects uneven recovery around the world, with stronger recovery in the US and Europe but lower travel in China and Asia due to ongoing Covid measures. Engine flying hours in Business Aviation remained strong and above the 2019 level year to date. Regulatory clearance for Boeing’s 787 aircraft has enabled aircraft deliveries to resume, and our related concession balance is starting to unwind as expected. The recovery in our flying hours and planned increase in spare engine sales will drive strong cash conversion, with operational cash expected to comfortably exceed operating profit in the medium term, as outlined in our Civil Aerospace investor day in May. Year to date shop visits volumes and original equipment (OE) deliveries are higher year on year but at the lower end of the expected range for this year. We are planning a higher volume of large spare engine sales in 2022 and for the next few years, versus the typical range of 10-15% of total OE deliveries, as we grow the pool of spare engines to underpin fleet health and improve resilience. Inflation linked customer contracts and procurement agreements are supporting long term service agreement (LTSA) margins, improving profitability in Civil Aerospace. This creates a positive contribution from contract catch-ups in 2022.
In Defence, we continue to see robust demand from our customers with $1.8bn in contract renewals and repricing relating to the next five years, to support engines in service, including those with the U.S. DoD powering the C-130J. As indicated at our first half results, we expect a low double digit percentage operating margin in Defence in 2022 and into the medium term, reflecting the planned increased investment in new defence programmes. Revenue growth in 2022 is expected to be modest due to the non-repeat of legacy spare parts sales that took place in 2021 with no material benefit from the increase in government defence budgets in the near term due to our long product cycle. We remain positive in the long-term outlook supported by recent awards including MT30 engines for UK and Australian frigate programmes and the B-52 reengining programme in the US. Active prospects include the US Army’s FLRAA programme which is due to announce selection shortly.
In Power Systems, the continued high levels of demand in many of our end markets is driving an exceptionally strong order book, with a record order intake year to date in 2022 and good revenue cover for 2023 and beyond. Order intake included an order for more than 500 mtu engines for the UK’s Boxer armoured vehicle and 16 gensets for four new frigates for the German Navy. This strong performance in part reflects pent-up demand as our end markets recover. Due to the shorter cycle nature of the Power Systems division, it has greater exposure to the current global supply chain disruptions than Civil Aerospace and Defence. As a result, there is a greater degree of inventory build in the Power Systems business. We continue to address supply chain challenges and we have started to see some improvement in working capital levels in recent weeks.
In New Markets, we continue to invest in technology to deliver on our transition to net zero. In our Electrical business, we welcomed the decision by European Union’s Clean Aviation programme to proceed with over €700m of funding for 20 aviation research and innovation programmes from across the industry. We will be a partner in six of these. In our SMR business, we entered into a memorandum of understanding with Czech nuclear engineering and manufacturing firm Škoda JS to explore deployment potential in the Czech Republic and broader central European regions.
Our Full Year 2022 results will be announced on 23 February 2023.