Definition
VREF is the reference landing speed used as the target airspeed for crossing the runway threshold during a normal landing approach. It is defined as 1.3 times the stalling speed in the landing configuration (1.3 VSO) at the maximum certificated landing weight. Aircraft approach categories (A through E) used for instrument approach planning are based on VREF.
Plain English
VREF is the speed a pilot aims to be flying as the aircraft crosses the start of the runway on landing. It is set high enough above the stall speed to give a safe margin, and it is used to group aircraft into approach categories that determine which approach minimums apply.
Context Anchor
Seen in instrument procedure rules and aircraft approach category tables, especially when deciding whether an aircraft is Category A, B, C, D, or E for an instrument approach.
Derivation
V stands for velocity, the standard aviation prefix for defined airspeeds. REF is short for reference, meaning the speed used as the reference point for the landing approach. So VREF literally reads as 'reference velocity' — the speed you reference when planning and flying the approach to landing.
Why Pilots Care
Maintaining VREF provides the required margin above stall while minimizing landing distance and ensuring stable approach criteria are met.
Intuition Check
Do not read VREF as just any preferred final approach speed. Here it means the published reference landing speed used for aircraft approach category purposes, or the FAA substitute value if no VREF is published.
Example Sentence 1
The crew briefed a VREF of 138 knots for the planned landing weight before starting the approach.
Example Sentence 2
Aircraft approach category is assigned using the highest VREF value at maximum certified landing weight.