Definition
A manually operated fuel quantity measuring device installed in the underside of an aircraft fuel tank. The technician unlocks and lowers a calibrated rod from beneath the wing until fuel begins to drip from its open end; the reading on the rod at that point, cross-referenced with aircraft attitude and fuel temperature, indicates the volume of fuel in the tank.
Plain English
A backup way to check how much fuel is in the tank by hand. A marked rod is pulled down from under the wing until fuel drips out of it, and the mark showing at that point tells you how full the tank is.
Context Anchor
Seen during aircraft maintenance, fueling checks, and fuel quantity checks on aircraft equipped with under-tank measuring sticks.
Derivation
Named for how it works: fuel drips from the open end of the stick once it has been lowered to the level of the fuel inside the tank. The 'stick' part reflects the long, calibrated rod itself.
Why Pilots Care
Provides a direct, physical confirmation of fuel quantity that does not rely on electrical systems or gauges.
Analogy
It is similar to checking engine oil with a dipstick, except the drip stick is built into the aircraft fuel tank and is read from below the tank.
Intuition Check
Do not read drip stick as a stick that causes a fuel leak. In this use, the drip is the signal that the measuring stick has reached the fuel level.
Example Sentence 1
With the fuel quantity indicator inoperative, the mechanic used the drip sticks to confirm the tank contents before the flight was released.
Example Sentence 2
During the inspection, the mechanic used the drip stick to verify the tank quantity after the aircraft had been fueled.