Do Pilots Turn Off Engines Mid-Flight?

The short answer is no, pilots generally do not turn off engines mid-flight. Doing so would put the plane in a dangerous situation that could lead to a catastrophic failure.

The Importance of Engines During Flight

The engines are crucial for maintaining the plane's forward momentum. This forward motion generates airflow over the wings, which in turn creates lift. This lift holds the plane up in the air. If the engines were to be turned off mid-flight, the plane would lose this forward momentum along with the necessary airflow to stay aloft. The result would be a descent, potentially leading to an uncontrolled crash.

The engines are the very reason a plane is able to stay in the air and fly.

Engine Shutdown in Emergency Situations

While engines are not typically turned off during normal flight, there are instances where they may be shut down during an emergency. In cases of malfunctions such as engine fires or severe mechanical issues, pilots may need to shut down an engine to prevent the situation from worsening. Even if the engine is still generating power, a multi-engine plane can often continue to fly using the remaining engines to a suitable airport. However, in the case of a single-engine plane, situations like an engine fire or other critical issues require immediate action to land the aircraft safely on the ground or water.

Flight Operations with Engine Shutdowns

There are certain aircraft that are specifically designed for engine shutdown during flight. These are rare but do exist:

The P-3 Orion

The Orion P-3 was a US Navy submarine-hunting aircraft equipped with four turboprop engines. During lengthy patrols at relatively low speeds, it was common practice to shut down two of the engines. This approach saved fuel as running two engines at moderate power consumed less fuel than running four engines at low power.

Motorgliders

A motorglider is a type of aircraft that is initially powered by an engine to take off and climb. The engine can then be shut down, and in some designs, retracted into the fuselage. After this initial powered phase, the aircraft operates as a glider for the remainder of the flight. This approach provides the convenience of powered takeoff while still achieving the efficiency of a glider for the rest of the journey.

However, it's important to note that propeller-driven aircraft designed to operate with a shut-down engine must have a mechanism to stop the propeller. This is typically achieved through feathering—aligning the blades so they are parallel to the wind. A windmilling propeller (one spinning due to airflow) would create significant drag, similar to having a flat plate of the same diameter attached to the plane, which would greatly impede its ability to fly.

Conclusion

While aircraft engines are not typically turned off during normal flight, there are valid reasons for their shutdown in emergency situations. The safety and reliability of modern avionics and in-flight monitoring systems, combined with stringent training and procedures, ensure that aircraft remain safe and capable of maintaining controlled flight at all times.