Definition
Aircraft piston engines that deliver fuel directly into the intake ports or cylinders through injector nozzles, rather than mixing fuel and air in a carburetor before it enters the engine. Because there is no carburetor venturi where pressure drops and air cools, fuel-injected engines are not subject to carburetor icing. They can, however, still suffer from impact icing at the air intake when flying through visible moisture at near-freezing temperatures, which can block the induction air supply.
Plain English
Engines that squirt fuel straight into the cylinders instead of mixing it with air inside a carburetor. They avoid the icing problem carbureted engines have, but ice can still form at the outside air intake and choke off the air supply.
Context Anchor
Seen in induction icing, engine operation, and abnormal engine-performance discussions, especially when comparing carbureted engines with fuel-injected engines.
Derivation
Inject' comes from the Latin 'injicere,' meaning 'to throw in.' That captures what the system does — it throws fuel directly into the engine rather than letting it be drawn in along with the air.
Why Pilots Care
These engines avoid carburetor icing but can still form ice in the air intake when flying through visible moisture at low temperatures.
Analogy
A carbureted engine is more like mixing fuel and air in one bowl before sending it to the engine. A fuel-injected engine is more like spraying the right amount of fuel into the air path as the engine needs it.
Intuition Check
Do not read “fuel-injected” as “safe from all induction ice.” It only describes how fuel gets into the engine; ice can still block the air going into the engine.
Example Sentence 1
Because the Cessna 182T has a fuel-injected aircraft engine, the checklist has no carburetor heat item, but it does include an alternate air source for impact icing.
Example Sentence 2
Maintenance checks on fuel-injected aircraft engines focus on injector cleanliness to prevent uneven fuel delivery.