Definition
A method of changing the blade angle (pitch) of a propeller only while the airplane is on the ground and the engine is shut down. The blades are loosened at the hub, rotated to the desired angle, and then locked in place. Once set, the pitch cannot be changed in flight.
Plain English
A propeller whose blade angle can only be changed on the ground by a mechanic, not by the pilot during flight. Once it is set, it stays at that angle until someone adjusts it on the ground again.
Context Anchor
Seen during outside-the-airplane inspections, propeller discussions, and airplane performance planning for aircraft with ground-adjustable propellers.
Derivation
"Ground adjustable" simply means "can be adjusted on the ground." The phrase is plain English describing exactly when and where the adjustment is possible, which is the whole point of the term.
Why Pilots Care
Lets the pilot or mechanic select an efficient blade angle for the expected flight conditions before departure without requiring an in-flight mechanism.
Intuition Check
“Ground adjustable” does not mean the propeller adjusts itself near the ground. It means the propeller blade angle can be changed only while the airplane is on the ground, not during flight. “Pitch” here does not mean the airplane’s nose-up or nose-down attitude. It means the angle or setting of the propeller blades.
Example Sentence 1
The mechanic loosened the hub bolts and reset the blades to a slightly flatter angle, since the owner wanted better takeoff performance from the ground adjustable propeller.
Example Sentence 2
After checking density altitude, the pilot chose a coarser ground adjustable pitch adjustment for better cruise efficiency.