FL290 refers to a flight level of 29,000 feet above sea level, commonly used in aviation. Flight levels are standardized altitudes used by pilots and air traffic controllers to ensure safe vertical separation between aircraft. At this altitude, planes typically operate in the lower part of the jet stream, which can affect fuel efficiency and flight time. Aircraft flying at FL290 are often cruising on long-haul flights, where they can avoid weather disturbances and turbulence found at lower altitudes. This level is also significant for commercial aviation, as it allows for optimal performance and safety during flight operations.