Most modern twin-engine airplanes, like the Boeing 737-800, are designed to fly safely on a single engine. This capability is crucial for ensuring passenger safety in case of an engine failure. While losing an engine significantly impacts performance, it doesn’t mean the plane will fall out of the sky.
Designed for Single-Engine Flight
Aircraft manufacturers build redundancy into their designs, particularly in critical systems like engines. Twin-engine planes undergo rigorous testing to certify their ability to fly and land safely with only one engine operational. This certification process ensures the aircraft can maintain altitude, control, and maneuverability even with a significant loss of power.
Maximum Landing Weight vs. Takeoff Weight
The Boeing 737-800, for instance, has a maximum takeoff weight of 66,990 kg and a maximum landing weight of 65,317 kg. This slight difference accounts for the fuel burned during a typical takeoff and initial climb. In the event of an immediate return to the airport after takeoff due to engine failure, the aircraft would likely be within its maximum landing weight limits. This allows for a safe landing without needing to dump fuel, as the fuel burned during the short flight would bring the aircraft’s weight below the maximum landing weight. This principle applies to most short- to medium-range airliners. They routinely fly shorter routes carrying fuel for multiple legs, a practice known as “tankering.”
When Fuel Dumping is Necessary
While engine failure itself doesn’t necessitate fuel dumping, other emergencies might. Situations such as flap/slat malfunctions, brake system issues, spoiler or landing gear problems require the aircraft to be as light as possible for landing. Reducing weight shortens the necessary landing distance, increasing the margin of safety. In these cases, pilots may circle to burn fuel or, in some aircraft, dump fuel to reach a safe landing weight.
Long-Range Aircraft and Overweight Landings
Long-range, wide-body aircraft typically have a larger difference between maximum takeoff and landing weights. This is because they carry significantly more fuel for longer flights. For these aircraft, fuel dumping or extended flight to burn fuel is more common in emergency situations to reduce stress on the landing gear and airframe. However, even these aircraft are designed to withstand a single landing at maximum takeoff weight if absolutely necessary. Such a landing would likely require a thorough inspection of the aircraft before its next flight to ensure no damage occurred.
Safety First
While the prospect of flying on one engine might seem alarming, it’s a scenario aircraft and pilots are well-prepared for. The ability to fly safely on a single engine is a testament to the robust design and safety standards of modern aviation. Procedures are in place to manage such events, prioritizing the safety of everyone on board.
