Originally Posted by
RedG
Previous replies nailed it when they pointed out that basically no commercial airliners today are turbojets. Your "jets" are actually turbofans. And turbofans are more similar to turboprops than you might think. Both turbofans and turbojets employ a gas turbine engine. Those "jet engines" you see on an A320 or 7X7 are actually basically a propeller-in-a-tube, or more properly a "ducted fan". While there are important technical and performance differences, at a high level they both "blow air" using a fan/propeller to achieve thrust.
Turbojets were replaced by turbofans as the latter were more fuel efficient and quieter. Turboprops it turns out are even more fuel efficient than turbofans on short haul routes, and even quieter. I personally really like them on short commuter-type routes.
This.... Also, turboprops are much more efficient at very low altitude. Turbojets are not gone though. They are very good for extemely fast or extremely high applications or where space or size is a consideration, such as cruise missiles. Turbojet engines are very fuel inefficient, dirty and loud which is why they were phased out of most commercial passenger fleets. Turboprops do have the problem of vibration though. Fly one for 3 or 4 hours and it can fatigue a pilot/passenger quickly.