This is what it looks like when the Air Force tests its jet engines

The Air Force's aircraft would be nothing without the incredible amounts of work and technology that goes into each airframe's engines.

To ensure the safetly and function of each engine, they are subjected to a series of incredible testing on the ground. At this point, the engines are not yet attached to aircraft. And even after a series of testing, engines are still subjected to frequent mechanical checkups to ensure as much as possible that nothing will go wrong mid-flight.

Even after engines are used in flight, they are frequently taken off of planes and checked and tuned up. Here, an afterburner glows during a test engine run and diagnostics on an F-15 engine following repair.

USAF/Master Sgt. Shelley Gill

Air Force spouses watch a US Air Force F-22 Raptor fighter aircraft engine run at the Hush House jet engine test facility.

US Air Force Reserve/Tech. Sgt. Dana Rosso

Senior Airman Daniel San Miguel, an aerospace propulsion journeyman, oversees an F110-GE-129 engine being tested during its afterburner phase at Misawa Air Base, Japan.

USAF/Senior Airman Deana Heitzman

Members of the 23rd Component Maintenance Squadron Propulsion Flight perform maintenance on a TF-34 engine that belongs to an A-10C Thunderbolt II.

USAF/Airman Greg Nash

Senior Airman John Fleetwood inspects an augmenter flame-holder and spray-rings during an engine tear down for an F-15.

US Air Force/Staff Sgt. Christopher Hummel