Transatlantic flight is the flight of an aircraft across the Atlantic Ocean, from Europe, Africa or Middle East to North America, Central America or South America, or west-to-east. Such flights have been made by fixed-wing aircraft, airships, balloons and other devices.Early aircraft engines did not have the reliability needed for the crossing, nor the power to lift the required fuel. There are difficulties navigating over featureless expanses of water for thousands of miles, and the weather, especially in the North Atlantic Ocean, is unpredictable. Since the middle of the 20th century, however, transatlantic flight has been routine, for commercial, military, diplomatic, and other purposes. Experimental flights (in balloons, small aircraft, etc.) still present challenges for transatlantic fliers.