Can Planes Use Reverse Thrust to Back Up?

Have you ever wondered if planes can use reverse thrust to back up, just like how a car or a boat operates? In reality, planes are primarily designed for forward flight, meaning their propulsion systems are optimized for that direction. However, under specific circumstances, such as during landing, certain types of aircraft can indeed utilize reverse thrust to assist in slowing down on the runway.

What Is Reverse Thrust?

Reverse thrust is a technique specifically employed to slow down an aircraft after landing. It works by redirecting the engine's exhaust forward instead of backward. This action generates a braking effect, which helps to decelerate the aircraft on the runway. It's important to note that, despite the name, reverse thrust doesn't propel the plane backward in the air; it merely helps reduce speed on the ground at a relatively low rate compared to forward taxiing.

Most commercial jetliners are equipped with thrust reversers, which can be deployed to enhance braking efficiency. These reversers can redirect the engine's exhaust flow, creating a resistive force that helps the plane slow down more quickly on the runway.

Reverse Thrust on the Ground

On the ground, jets and most turboprops can use reverse thrust to back up, albeit only under specific conditions. Reverse thrust is a powerful tool for aiding in the deceleration of aircraft after landing, but it is generally strictly controlled to ensure safety. Some airlines have strict prohibitions against using reverse thrust for backing up, as it can be dangerous if not properly managed. For example, if the pilot accidentally taps the brakes while moving in reverse, it's easy to have the plane sit on its tail. Reverse thrust is typically used during the landing phase to assist in slowing down the aircraft.

Flying in Reverse Thrust

In flight, the use of reverse thrust is quite rare. Despite the capability, very few aircraft can actually use reverse thrust while airborne. The only recorded instance is a specially modified Gulfstream aircraft used for NASA training purposes. When the Space Shuttle returned to Earth at a steep angle, it was necessary to use in-flight reverse thrust to simulate the drop angle of the shuttle.

Real World Example - DC-9/MD-80 Series

A real-world example of using reverse thrust can be seen in the DC-9/MD-80 series aircraft. These jets can use reverse thrust to back up, but it requires careful operation. One incident occurred at TWA/AA Orlando Airport on September 12, 2001. During this event, the plane was rolling backwards with only two mechanics in the cockpit, and one of them accidentally stepped on the brakes. The result was the plane nearly stood on its tail, with the cockpit rising about 20 feet higher as it braked.

Reverse Thrust and Certification

Although some aircraft can use reverse thrust to back up, it's not common and is typically reserved for emergency or unusual procedures. Pilots must be specifically trained to operate under these conditions, and the aircraft must be certified to use reverse thrust. This usually only applies to certain types of commercial and military airplanes. For instance, 727s have been known to use reverse thrust occasionally, and many pilots have seen C-130 planes perform this maneuver for landing assistance.

Reverse thrust is a fascinating and specialized technique in aviation, primarily utilized to enhance the effectiveness of landing and braking. While not as versatile as a car's reverse gear, reverse thrust can play a crucial role in ensuring a safe and efficient landing. Understanding its use and limitations is crucial for both pilots and aircraft operators.