Definition
The end of an aircraft engine's crankshaft to which the propeller is attached. It is the forward end of the crankshaft on most tractor-configuration engines and is machined with a flange, splines, or a tapered shaft to accept the propeller hub.
Plain English
The end of the engine's main rotating shaft where the propeller bolts on.
Context Anchor
Seen in aircraft engine maintenance descriptions when identifying engine sides, inspection areas, leaks, parts, or damage locations.
Derivation
“Propeller” comes from Latin words meaning “to drive forward.” In this term, it points to the engine end that drives the propeller and sends power into it.
Why Pilots Care
When reading engine documentation or troubleshooting, knowing which end is the propeller end helps a pilot or technician orient themselves correctly. Inspections, timing references, and crankshaft component locations are often described relative to the propeller end versus the accessory end.
Intuition Check
Do not read “propeller end” as the end of a propeller blade. In this maintenance context, it means the end of the engine where the propeller is mounted.
Example Sentence 1
The crankshaft thrust bearing is located near the propeller end to handle the forward pull from the spinning propeller.
Example Sentence 2
Bearings at the propeller end support the crankshaft loads from the spinning propeller.