#1 How does an engine actually work?

- Firstly, air is sucked in through the large inlet of the engine. Some of this air is compressed in various stages in the core engine using compressor blades, increasing the pressure of the air many times over.

- The compressed air is then mixed with fuel in the combustion chamber and burned continuously. The hot gases produced (up to approx. 1,500 °C) drive a turbine, which in turn drives the upstream compressor and the characteristic fan blades.

- The still hot air now leaves the turbine at a slightly higher pressure. The air is accelerated in the component known colloquially as the ‘nozzle’ and exits the engine. It is this final acceleration step that produces the thrust and propels the engine and thus the aircraft forward.

- It is worth noting that only a small proportion of the air sucked in (10 to 20 per cent depending on the engine type) is subjected to combustion in the core engine. The lion's share of the air is channeled around the core engine by the so-called sheath flow. The air from the sheath flow is compressed by the complex fan blades and then also accelerated in a ‘nozzle’. The fan blades thus contribute to most of the thrust.

#2 Big, bigger, engine!

Before you board the aircraft, you have the chance to see the large engines from different angles. The Boeing 777-300ER clearly has the largest engines in the SWISS fleet. ‘We're talking about a diameter of 3.20 metres, a length of a good 7.3 metres and a weight of around 8.7 tonnes,’ explains Matthias Schmidhauser, Head of MRO* Service Procurement at SWISS. Its impressive size is also accompanied by impressive performance, which is particularly advantageous for long-haul flights and large passenger capacities. ‘The thrust of a Boeing 777-300ER engine is 52 tonnes,’ explains Michael Schib, Head of Center of Competence Engines at SWISS.

*MRO stands for Maintenance, Repair, and Overhaul.

#3 Expensive, but worth it

One thing is certain: a new engine costs a lot of money. ‘Depending on the type, the price can be in the mid double-digit million range,’ says Matthias Schmidhauser. However, this amount only applies if the engine is purchased individually and not as part of a complete aircraft purchase. Schmidhauser also emphasises: ‘The engine is the most important and most expensive component on the aircraft.’

But an engine is also durable. ‘The service life of an engine can be up to 40 years,’ says Schib. However, parts are regularly replaced during scheduled maintenance work in the workshops, which in turn incurs costs.

#4 So much manual labour is involved

Despite advances in automation, manual labour still plays a crucial role in the aircraft industry, especially when assembling and disassembling engines. ‘During a planned repair visit to the workshop, machines are used to measure, calibrate, turn and grind components. But you can't do it without people,’ emphasises Matthias Schmidhauser. At least four people work over six to eight shifts to completely dismantle a medium-sized engine.

#5 Sustainability through technological progress

The technology behind an engine is sophisticated and is constantly being improved with the aim of lowering fuel consumption and reducing emissions. New materials such as composite materials or special metal alloys reduce the weight and make the engines more heat-resistant and durable. ‘Existing engine types are also constantly being further developed over the course of their service life with the airlines,’ explains Michael Schib.  Engines are also equipped with numerous sensors that enable predictive maintenance. This extends the service life of the engines and reduces the consumption of spare parts, which indirectly helps to conserve resources.