Technology
How does a jet engine work?
A jet engine works by sucking in air, compressing it, mixing it with fuel and burning it, then blasting the hot exhaust out the back. That high-speed jet of gas pushes the engine — and the plane — forward, following Newton's third law.
See it in motion.
Watch a 2-minute animated lesson that shows exactly how a jet engine works.
Step by step
- 1A spinning compressor squeezes incoming air to high pressure.
- 2Fuel is sprayed in and ignited, making hot, rapidly expanding gas.
- 3The gas rushes out the back at high speed, producing forward thrust.
- 4On the way out it spins a turbine that drives the compressor up front.
- 5Thrust follows Newton's third law: push exhaust back, the engine goes forward.
Frequently asked questions
- How does a jet engine create thrust?
- It throws a large mass of hot gas backward at high speed; by Newton's third law, an equal force pushes the engine forward.
- What's the basic cycle of a jet engine?
- Suck (intake air), squeeze (compress it), bang (burn fuel), blow (expel exhaust) — repeated continuously.
- Do jet engines work in space?
- No. They need oxygen from the air to burn fuel; rockets carry their own oxidizer, so only rockets work in the vacuum of space.