How Jet Engines Work: A Simple Guide

 

Introduction

Jet engines power the aircraft that move millions of people every day. Though they look complex, the basic science behind them is surprisingly simple: air goes in, gets compressed, mixes with fuel, ignites, and blasts out the back, creating thrust. Here’s an easy breakdown anyone can understand.

1. The Basic Principle: Newton’s Third Law

Jet engines operate on a simple rule—every action has an equal and opposite reaction.
When air is pushed out the back of the engine at high speed, the airplane moves forward.

2. The Four Main Steps Inside a Jet Engine

Modern jet engines follow a cycle known as suck, squeeze, burn, blow.

Step 1: Suck (Air Intake)

Air enters through the front fan. These huge spinning blades pull massive amounts of air into the engine.

Step 2: Squeeze (Compression)

The air passes through compressors—multiple spinning blades that squeeze the air, raising its pressure and temperature.

Step 3: Burn (Combustion)

Fuel is sprayed and ignited in the combustion chamber.
This explosion dramatically accelerates the air.

Step 4: Blow (Exhaust & Thrust)

The hot, high-pressure air shoots out the rear nozzle, generating thrust that pushes the aircraft forward.

3. The Fan Produces Most of the Thrust

On modern turbofan engines, like those on the Boeing 777 or Airbus A350, the large front fan produces about 80% of the total thrust.
The core of the engine (compressor, combustion, turbine) powers the fan.

4. Turbines: The Engine’s Power Source

Behind the combustion chamber, turbines rotate using the hot exhaust gases.
These turbines are connected by a shaft to the front compressor and fan—powering the entire engine.

5. Why Jet Engines Are So Efficient

• High bypass ratio = more thrust from the fan

• Light materials like carbon fiber reduce fuel burn

• Advanced blade design reduces drag

• AI monitoring improves engine performance

Conclusion

Jet engines are engineering marvels, but their basic operation is straightforward. Understanding the “suck, squeeze, burn, blow” cycle makes it easy to grasp how modern aircraft achieve incredible speed and efficiency.