What is a demonstrated crosswind component? Is it possible to land in a crosswind greater than the demonstrated crosswind component? Is it safe to?
A demonstrated crosswind component is highest crosswind (corrected to make it 90°) which has been shown to be possible to safely land by a test pilot. It shall not require exceptional skill by an ordinary pilot, however it does not mean every pilot will be able to do so. It is also NOT a limit (contrary to what some say) - if the pilot does decide to land higher crosswinds, they can do so (but please take caution).
This number may not necessarily be the highest crosswind component that it's possible to land in -- it just has to be above the minimum capabilities required in the regulations. For example, say an aircraft, flown perfectly (yes, we're dreaming), was capable of handling a 30 knot crosswind component (no gust, ISA conditions), the manufacturer only needs to demonstrate safe landing with a crosswind component of one-fifth of the reference stall speed in the landing configuration. This would be:
- 10 knots @ 50KIAS VS0
- 12 knots @ 60KIAS VS0
- 14 knots @ 70KIAS VS0
- 15 knots @ 75KIAS VS0
(a) A 90 degree cross-component of wind velocity, demonstrated to be safe for taxiing, takeoff, and landing must be established and must be not less than 0.2 VS0.
I teach a way simpler definition: The maximum crrosswind component that a plane can hold the fuselage aligned to the centerline up until full deflection of the controls.
Any additional wind requires adding in crab and would result in a side-loaded touchdown which is therefore out if control.