Max Demonstrated Crosswind Checker
Compare today's crosswind component against your aircraft's demonstrated value and your own personal limit — with the verdict spelled out.
Demonstrated crosswind is not a certification limit — it is what a test pilot showed during certification, with no claim it's the maximum possible. But exceeding it puts you in flight-test territory without the test pilot.
Formula
⚠️ For flight planning and education only — always verify against your aircraft's POH/AFM, official weather sources and certified instruments. Not for primary navigation or airworthiness decisions.
Compare today's crosswind component against your aircraft's demonstrated value and your own personal limit — with the verdict spelled out.
About Max Demonstrated Crosswind Checker
The 'max demonstrated crosswind' line in the POH is one of aviation's most misunderstood numbers — neither a hard limit nor a casual suggestion. This checker computes today's component and stacks it against both that demonstrated figure and the more important number: the personal limit you set for yourself in calm reflection rather than on short final. The verdict logic deliberately treats your own limit as the binding one.
How to use Max Demonstrated Crosswind Checker
- 1Enter — sensible defaults are pre-filled so you see a worked result immediately.
- 2Read the live results: .
- 3Check the "With your numbers" line to see the formula crosswind = W·sin(Δ) compared against demonstrated and personal limits substituted step by step.
- 4Adjust inputs (or flip the unit toggle) until the scenario matches yours, then copy or share the result.
Why use Max Demonstrated Crosswind Checker?
- ✓Instant, free and private — every calculation runs in your browser, nothing is uploaded
- ✓Built on the published formula crosswind = W·sin(Δ) compared against demonstrated and personal limits with sources cited on the page
- ✓Demonstrated crosswind is not a certification limit — it is what a test pilot showed during certification, with no claim it's the maximum possible. But exceeding it puts you in flight-test territory without the test pilot.
- ✓Switch units, tweak any input and watch every result update live
Frequently asked questions
Is max demonstrated crosswind a legal limitation?+
Usually not. For most light aircraft it appears in the performance or normal-procedures section as the value 'demonstrated' during certification flight testing (required to be at least 0.2 × Vso), not in the limitations section. Some aircraft and most operators' SOPs do elevate it to a hard limit — your POH's limitations section and your operator's rules decide.
Why set a personal limit below the demonstrated value?+
The demonstrated figure was flown by a current, briefed test pilot on a dry, known runway in steady wind. Your currency, the gusts, runway contamination, fatigue and width all subtract from that. A common framework: recent crosswind practice → within 2–3 kt of demonstrated; rusty → half to two-thirds of it, raised deliberately through dual practice.
What actually runs out first in a strong crosswind?+
In a sideslip landing, rudder authority — at some component you can no longer hold the nose straight with full rudder while the upwind wing is down. In a crab-and-kick landing, it's timing and drift at touchdown. Demonstrated values approximate where control margins start to pinch for average technique; tailwheel aircraft pinch much earlier.
Should I use the steady wind or gusts in this checker?+
Enter the gust value for the wind speed — the gust is what your control authority must answer during the flare. If the result is beyond limits on gusts but fine steady, that's not a pass; it means the deciding gust may or may not arrive in your flare, which is a lottery, not a margin.
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