Large transport category airplanes: Turbine engine powered: En route limitations: One engine inoperative

This regulation limits the takeoff weight of turbine-powered large transport category airplanes to ensure they can safely continue flight if one engine fails en route. The airplane must be able to either maintain a positive climb gradient at least 1,000 feet above terrain within five miles of the route (1,500 feet above the landing airport for newer aircraft), or descend from cruise altitude to an alternate airport while clearing all terrain by at least 2,000 feet vertically.

The calculation assumes the engine fails at the worst possible point and accounts for normal fuel consumption, adverse winds, and proper navigation fixes. Operators must use the one-engine-inoperative performance data from the Airplane Flight Manual, considering expected en route temperatures. Fuel jettisoning may be included in planning if the crew is properly trained. This ensures that even with an engine failure, the flight can safely reach a suitable airport rather than being forced down into terrain.

*This is a plain-English summary for study only. The official 14 CFR text on this page is controlling — always read the current regulation and consult a CFI.*