A Jumbo Jet Engine - How to Build

Fantastic. BBC How to Build A Jumbo Jet.

The top is Turbofan. The bottom is Turbojet. The enormous fan is what distinguishes a modern jumbo engine from older Turbojet.

Turbojet didn't have a fan at the front and relied entirely on  the jet exhaust to thrust the plane forwards. Faster than the propeller but inefficient and very noisy.

Fan Blade.The fan blade delivers 75% of the engine's thrust. It shifts about 1.2 tonnes of air per second. The loading on the blade is something like 90 tonnes centrifugal load, as it's full throttle. Every single fan blade is worth as much an average family car. For each blade, three metal sheets are bonded together to make a solid titanium sandwich. It's a extremely secret process which can't allow to be shown on this video.

Turbofan, the energy of the exhaust is harvested to turn the massive fan blades at the front,
which in turn push huge amounts and that's what thrusts the airplane forwards.

Solid sheets of high-grade titanium.Transform raw material into high performance fan blades.

Hollow Blade is the top secret. The original blades used to be solid, but to get better performance and take weight out of the engine.It was designed to be hollowed. The hollow blade is like Corrugated Fiberboard.

Shear Key. Two shear key will ride on and locate in the slot.

The unique process begins, when the titanium layers are bonded together in a secret pattern.

The whole blade is inflated like a balloon, pulling and stretching the inner layer across the cavity,like cheeses between slices and  pizza.

Super light and sturdy internal structure.

Before it can be inflated, the flat titanium sandwich has to be heated and twist into the shape.

Used inert gas to inflate which didn't react with the titanium at high temperature.

A heat resistant tube connects the blade to a high pressure gas supply. But the gas alone won't be enough to inflate the blade. The whole assembly also has to be loaded into a furnace at a secret critical temperature.

A single speck of dust could cause a lot of damage. Despite the precision of the engineering, no two finished blades are exactly alike.

The blade will only spin smoothly if each blade is perfectly balanced. So every blade is precisely measured and weighed, then rung like the bell.

Each blade has different mass and frequency, used the data to select where they  will be positioned in the disk. so when it goes to engine build, they go in exactly locations.