The problem with Power-by-the-Hour is that, when you describe it aloud, it sounds unimpressive. For each hour an engine is in the air, an airline must pay a fee. The maintenance is done by the manufacturer. That’s all. However, this modest, almost bureaucratic-sounding setup, which was developed in 1962 to support a Viper engine on a Hawker Siddeley 125 business jet, might be the most significant financial innovation in aviation history. It subtly changed how lessors safeguard billion-dollar assets, how airlines budget, how aircraft are financed, and—possibly most oddly—how engineers view reliability itself.
For the majority of the post-war period, engines were marketed similarly to refrigerators. You purchased one, it was yours, and you had to pay the repair shop’s quote when it broke. For airlines, the economics were harsh, but for manufacturers, who made good money on engines and great money on spare parts, the situation was strangely profitable. When Rolls-Royce, which at the time had a near-permanent talent for almost going bankrupt, examined this arrangement, it saw something that most of its competitors missed. The malfunctions were erratic. Customers detested the unpredictable nature. Strangely, when the manufacturer’s products failed, they were rewarded.
They then turned it upside down. Set a fixed fee for each flight hour. Assume accountability for the engine’s airworthiness. The airline and Rolls-Royce are not compensated if the engine is sitting on the ground in a hangar in Frankfurt due to a turbine blade problem. Looking back, it seems like this was more of an ethical choice than a business one. Reliability suddenly became a revenue strategy rather than a cost line. Derby’s engineers weren’t just creating engines; they were creating devices that had to function because the company’s quarterly results depended on them.
What began as a specialized arrangement for a single British engine spread covertly. Rolls-Royce rebranded the idea as CorporateCare for business jets and TotalCare for commercial wide-bodies by the 1990s. The economy had drastically changed. According to some industry estimates, the lifetime profit from service contracts can now reach seven times that of the original engine sale. Currently, services account for more than half of Rolls-Royce’s civil aerospace revenue. In a way, the engine has taken the lead in terms of losses. The relationship that follows it onto the wing for ten years is the real product.
The extent to which this concept has permeated the rest of the industry is difficult to ignore. In essence, GE Aerospace uses the same model. Pratt & Whitney does the same. These days, lessors build leases around it. Similar to how utilities project electricity demand, airlines incorporate it into their cash-flow projections. The model withstood the supply-chain devastation of 2022 and 2023 as well as the pandemic, when grounded fleets momentarily violated its fundamental premise: if planes don’t fly, no hours accrue, no money flows. It did not endure unharmed. These contracts are complex, multi-decade affairs that can break under pressure, as evidenced by the ongoing legal dispute between United Airlines and Rolls-Royce over a $175 million payment, which has essentially put 45 A350 orders in limbo. There is nothing wrong with the marriage analogy.
However, the subtle philosophical inversion at its core is what keeps this story alive. The objective is no longer to increase product sales. It’s selling fewer breakdowns. Supporters of Tesla make a similar argument regarding over-the-air software updates; SaaS companies based their entire valuation on the same reasoning. As you watch this develop over the course of six decades, it becomes clear that Rolls-Royce arrived first, most likely without realizing the extent of their influence. The model’s applicability in hydrogen, electric, or hybrid aviation—where reliability assumptions have not yet been validated—remains uncertain. However, the template is already in place. Someone’s clock is running every time an engine spools up over the Atlantic, and somewhere in Derby, a quarterly forecast is updating itself in real time.