How Difficult Is It To Build Aircraft Engines?

How difficult is it to build aircraft engines? The inside is burning at 1600 degrees Celsius, and the outside is not hot at all

Aviation engines are the "heart" of airplanes. Civil aircraft engines focus on safety and reliability, while military engines also pursue greater thrust and maximum thrust when driving afterburner. It can be seen that the strongest in the field of aviation engines is undoubtedly military aircraft engines, and military engines can be considered the pinnacle of human technology. Countries that have the capability to research and develop, manufacture, and produce aviation engines generally do not easily export their own technology, only exporting finished engine products, and some even need to send them back to their country of origin for maintenance. How difficult is it to build aircraft engines? The manufacturing difficulty lies in its complex structure and high precision requirements, involving multiple aspects such as material selection, design, manufacturing, control systems, and strict testing. Let's take a look together.

Difficulty in copying and disassembling

The difficulty in manufacturing aviation engines is first reflected in the difficulty of copying and disassembling. The shape of a car or aircraft can be replicated through reverse mapping, not to mention cars, which are easy to replicate. Copying the appearance of aircraft is also possible, such as the Tu-160 and B-1B bombers, but copying the engine is impossible without the involvement of drawings. For example, the mainstream CFM-56 series engines currently used on Boeing 737 aircraft have produced over 20000 units since their first operation in 1974. Almost all of Boeing and Airbus's flagship single aisle passenger planes have been used.

When disassembling CFM-56, it can be found that there are many small pores covering the nail sized area on the engine blades, which cannot be replicated without drawing positioning. Once the position of the air hole is incorrect, it will directly affect the heat dissipation of the blade, and the overall performance of the replica will decrease. GE has developed engines that cover various aircraft models based on the technological foundation of CFM-56, competing directly with Pratt&Whitney.

Difficulty in material manufacturing

The aviation engine is actually quite simple. Taking the classic CFM-56 engine as an example, it includes a low-pressure compressor, a nine stage high-pressure compressor, a first stage high-pressure turbine, and a fourth stage low-pressure turbine, with an annular combustion chamber in the middle. But just because these structures work in different temperature and pressure environments, it indicates that the materials used are different. Taking turbine blades as an example, the working environment is thousands of degrees Celsius, with tens of thousands of revolutions per minute. It is made of a mixture of various metals, and the proportions are also different.

Because the blades near the combustion chamber are subjected to higher temperatures and the materials are also resistant to high temperatures, the proportion of rare metal elements is different. If all high-temperature resistant materials are used, the unit price will be high, the economy will be poor, and it is best for commercial operation of civil aircraft engines to be cheap and easy to use.

Similarly, apart from the turbine blades, the materials used for each component of the engine are also different. The CFM-56 engine turbine used in the Boeing 737 is made of high-temperature alloy, while some other parts use composite materials. The currently popular material is resin based composite, which is used in the Pratt&Whitney F-119 external channel gearbox. It can withstand temperatures of 400 degrees Celsius and its cost can also be controlled.