Not on a standard transatlantic flight. You are likely seeing the optical effect of the window on the horizon. Observing curvature of the earth at even 60,000 f

Not on a standard transatlantic flight. You are likely seeing the optical effect of the window on the horizon. Observing curvature of the earth at even 60,000 feet requires a very wide-angle view (the cabin), with a clear view of the sky. The earth is huge. https://simpleflying.com/concorde-earth-curvature/ https://simpleflying.com/concorde-earth-curvature/