Crosswind & Density Altitude

Crosswind is the one-screen preflight calculator for student and GA pilots. Pick your runway, dial in the METAR wind, and get the two numbers that decide the flight: headwind and crosswind — computed for both the steady wind and the gust — with no full flight computer needed. The wind screen: - A drawn compass rose shows your runway strip at its true heading, the wind arrow blowing in from its direction, and the wind split into shaded headwind and crosswind vectors. Everything updates live as you turn the wheels. - Crosswind is labeled from the LEFT or RIGHT, gusts get their own readout with the gust factor, and a tailwind triggers a loud warning that names the opposite runway. - One tap flips the runway to its other end ("RWY 09 / 27"), and tapping the rose opens a full-screen close-up. Your minimums, not someone else's: - Set your own maximum crosswind and maximum gust factor. Every result is graded green, amber from 80% of your limit, and red at or above it — the go/no-go picture in one glance. Defaults are conservative and fully editable. Density altitude for hot-and-high days: - Enter field elevation, altimeter setting (inHg or hPa), and temperature (Celsius or Fahrenheit). Crosswind shows pressure altitude, the ISA deviation, and density altitude, in plain language: "your aircraft performs as if the field were at 8,744 ft." - An optional dew point adds an honest humidity hint — moist air is less dense, so the true figure runs slightly higher. No fake precision. Best runway at a glance: - A table of every heading 01–36 against the entered wind, sorted so the smallest crosswind wins and tailwind headings sink to the bottom. The best heading is tagged, your entered runway is marked, and every row is colored against your crosswind limit. Built like an instrument: - A dark cockpit look with big monospaced digits, wind always in knots, and your inputs remembered between flights. - One-time purchase. No subscription, no ads, no account, and no network requests of any kind — it works in the run-up area with zero bars. The math is the standard flight-school wind triangle and standard-atmosphere formulas, stated plainly in the app. Crosswind is a training and planning aid only — not for primary flight operations. Always verify wind, weather, and performance with official sources and your aircraft's POH.