FlightPath FAQ

It depends on your flight direction and time of day. On eastbound morning flights the sun tends to be on the right side; on westbound afternoon flights it's also typically on the right. But it changes constantly based on your exact route, latitude, and departure time. FlightPath calculates the exact shaded side for your specific flight.

Yes. Middle and aisle seats receive very little direct sun regardless of side. The seat recommendation from FlightPath is most useful if you have or are choosing a window seat.

There's no universally better side — it completely depends on your route direction, the time of day, and the season. A flight from New York to London in the morning may have the sun on the left all the way; the same route in the other direction in the afternoon may flip entirely. Use FlightPath with your specific flight details.

Absolutely. FlightPath's solar timeline shows exactly when the sun will be visible from each window side throughout your flight, including the altitude and azimuth. If you want the sunset side, just check which side has sun during the final 30–60 minutes.

For night flights, FlightPath marks the flight as a 'night flight' and there's no sun-side recommendation needed. For the best stargazing, choose a window seat away from the aisle lights, and check the moon phase — a new moon night gives the darkest sky. The moon position isn't tracked in the current version.

Any time before you book or before seat selection closes. The calculation only needs your route, departure date, and departure time — all of which are known as soon as you book. Checking early means you can select the right seat before the good ones are taken.

Airplane windows are made of acrylic (Plexiglas), which blocks UVB rays almost entirely but transmits 40–55% of UVA rays. UVA penetrates deeper into the skin, contributing to premature aging and melanoma. Unlike UVB, you don't feel UVA — there's no sunburn sensation — which makes it easy to underestimate.

Yes, significantly. UV intensity increases approximately 10% per 1,000 meters of altitude. At typical cruising altitude of 35,000 feet (~10,700 m), UV is roughly 2–3× more intense than at sea level. Commercial pilots have roughly twice the melanoma incidence of the general population, which researchers attribute largely to this UV exposure.

Yes, especially if you have a window seat on the sun-facing side during a long daytime flight. Dermatologists recommend at least SPF 30 and preferably SPF 50 for window passengers on multi-hour daytime flights. FlightPath's UV Dashboard gives you a flight-specific SPF recommendation based on your exact route, altitude, and sun exposure time.

It varies significantly. A 4-hour window seat flight during peak daylight hours on a sun-facing side can expose you to the equivalent of 15–30 minutes of midday sun. Short flights, night flights, and aisle seats have negligible UV exposure. FlightPath estimates this for your specific flight.

Some newer aircraft (notably the Boeing 787 Dreamliner) use electrochromic window dimmers instead of pull-down shades, and their windows use a different material that may offer different UV properties. However, no current commercial aircraft window fully blocks UVA. The safest assumption is that UV protection is needed for any long daytime window seat.

FlightPath recommends SPF based on your estimated UV exposure. As a general rule: SPF 30 for flights under 3 hours with partial sun exposure; SPF 50 for long-haul flights with significant window sun. Apply before boarding and reapply for flights over 4 hours. The UV Dashboard gives you a personalized number.

FlightPath uses the open-source SunCalc library to calculate the sun's azimuth (compass direction) at each waypoint along your flight path. It compares the sun azimuth to your aircraft's heading at that point to determine which side of the fuselage faces the sun. The side that faces away from the sun for the majority of the flight is the recommended shade side.

You need four things: origin airport (IATA code, e.g. JFK), destination airport (IATA code, e.g. LHR), departure date, and departure time (your local time). Optionally you can adjust flight duration if you know it's different from the default estimate.

No. FlightPath calculates a great-circle route between your origin and destination airports and uses the departure time you enter to compute solar position. It does not connect to any flight tracking API or use actual aircraft position data. This means it's fully offline and private — but it assumes a direct routing.

Yes, completely free. No account, no sign-up, no ads. It runs entirely in your browser — your flight details are never sent to any server. The project is built and maintained by Hrittik as an open utility for travelers.

Currently FlightPath analyzes one flight segment at a time. For connecting flights, enter each segment separately. This gives you the most accurate recommendation for each leg individually.

The solar position calculation is very accurate — SunCalc is used by astronomers and solar researchers. The main simplification is the great-circle routing, which closely matches most direct commercial flight paths. For heavily curved routes (e.g. polar routes), the actual sun-side timing may differ slightly from the recommendation, but the dominant shade side is usually correct.