Definition
An ATC instruction directing a pilot to increase the aircraft's airspeed to a specific value stated by the controller, and to maintain that speed until further advised. The controller will state the speed in knots (e.g., 'Increase speed to 250').
Plain English
ATC is telling you to speed up to the number they give you, and hold that speed until they tell you otherwise.
Context Anchor
Heard in radio communications when a controller needs aircraft spacing, sequencing, or traffic flow adjusted.
Why Pilots Care
Following the instruction maintains proper separation from other traffic and prevents delays or conflicts in busy airspace.
Intuition Check
Do not read “increase speed to” as “speed up a little” or “go as fast as possible.” It means accelerate to the specific speed the controller gives, if safe and possible.
Example Sentence 1
Approach told us, 'Increase speed to 230,' so we accelerated and held that speed for the arrival.
Example Sentence 2
Approach control said increase speed to 180 knots so the aircraft would slot properly behind the one ahead.