Definition
The highest crosswind component at 90 degrees to the runway that was actually flown and proven controllable during the airplane's certification testing. It is published in the Pilot's Operating Handbook and reflects what the test pilot demonstrated, not a structural limit or a guaranteed maximum capability.
Plain English
The strongest sideways wind that test pilots actually proved the airplane could handle during takeoff and landing testing. It is a reference number, not a hard limit.
Context Anchor
You will see this term when checking an airplane’s handbook before deciding whether the wind is acceptable for takeoff or landing.
Derivation
Demonstrated' means 'shown to be true through action.' The number was shown to work during testing — it was not calculated or estimated. That is why it is called demonstrated rather than maximum.
Why Pilots Care
It gives pilots a concrete, tested limit to compare against current wind conditions before attempting takeoff or landing.
Grounding Statement
If the wind is blowing across the runway, this value helps you judge whether that sideways push is within the range the airplane has already proven it can handle.
Intuition Check
Demonstrated does not mean absolute maximum or personal permission. It means “shown during testing,” and your own safe limit may be lower.
Example Sentence 1
The POH lists a demonstrated crosswind velocity of 17 knots, so with a 20-knot direct crosswind reported, the pilot chose to divert to a runway better aligned with the wind.
Example Sentence 2
The student checked the demonstrated crosswind velocity in the pilot’s operating handbook before practicing landings in the reported wind.