Definition
The airspeed at which the main wheels first contact the runway during a normal landing. For most light airplanes, this is just above the power-off stalling speed in the landing configuration, with the airplane in a slightly nose-high pitch attitude.
Plain English
The speed the airplane is travelling through the air at the exact moment its wheels first touch the runway.
Context Anchor
You encounter this term when learning the round out and flare, where the goal is to let the airplane slow and settle onto the runway under control.
Derivation
“Touchdown” comes from the plain idea of something touching down on a surface. In aviation, it has a precise meaning: the wheels first make contact with the landing surface. “Speed” is the rate of movement, so “touchdown speed” means the rate of movement at that first contact.
Why Pilots Care
Proper touchdown speed keeps the landing roll within runway length and prevents bounces or excessive tire wear.
Intuition Check
Touchdown speed is not the same as approach speed. Approach speed is before landing; touchdown speed is the speed at the instant the wheels first touch.
Example Sentence 1
The instructor reminded the student that touchdown speed should be just above stall, with the nose held slightly high as the wheels settled onto the runway.
Example Sentence 2
A higher than normal touchdown speed extended the landing roll and required more runway.