When you drive your car, you can easily control the vehicle in forward and reverse. You can back out of your parking space and then drive away, all under your own power. Is this how pilots can maneuver their planes on the ground? The answer may surprise you.
Table of Contents
No, airplanes don’t have a reverse gear. There is only one time when airplanes need to go backward, and that is when they are pushed back from the gate. While some types of planes could technically do this on their own, most airports require tugs to push the plane away from the terminal.
Why Do Planes Not Have Reverse Gears?
A plane needs to have the air flowing over its wings to fly. It can’t stay aloft without maintaining its minimum forward airspeed. If a plane needs to turn around, it will have to make the turn.
But the good news is, there’s no reason for a plane to need to reverse. In the air, there’s plenty of space for planes to turn whichever way they need to.
But on the ground is a different story. Airports are tight spaces with many taxiways and runways, but they are designed to allow planes plenty of room to make turns and get where they need to go. Even if a pilot misses a turn, they will have room to get where they need to go via another route. And while they might not be able to back up, they can make very tight turns.
On the more technical side, most planes don’t even have “gears.” A plane’s engines produce power going only one way–they are designed to push the plane forward. On the ground, the wheels have no power like a car. Power only comes out of the engine or the propeller.
Can a Plane Reverse on Its Own?
Even though a plane doesn’t have an actual reverse gear, many jet planes are equipped with devices called thrust reversers. Thrust reversers are part of the turbine engines that duct the powerful exhaust air forward instead of backward.
Jets are simple devices (in theory) that (start to) work by compressing the incoming air and creating a powerful exhaust that is blown out the back of the engine. Thanks to Newton’s Third Law of Motion (for every action, there is an equal and opposite reaction), the plane moves through the air.
By ducting the air forward instead of behind the plane, the opposite thing occurs. The thrust reversers will produce a burst of power that will pull the plane backward.
What is Reverse Thrust on a Plane?
The systems that make reverse thrust happen on a plane vary from model to model. Many planes have a design that pilots refer to as “buckets.”
This bucket-style of thrust reverser consists of two clamshell shaped flaps that pop out and cover the jet engine’s exhaust. When the exhaust hits these closed flaps, it is reflected forward. The resultant force pulls the airplane back.
Another style of thrust reversers, often seen on airliners, is the pivot-door style. These systems incorporate a series of doors on the sides of the engine nacelles. When they open, air from the main turbofan is deflected out of its regular path through the nacelle. Instead, it goes outside and forward, resulting in a backward pull on the plane.
Thrust reversal systems are primarily used by pilots to slow the plane down during landing. Even though the plane is still traveling forward down the runway, applying reverse power makes it slow down quicker. That means that the plane will use less runway.
The most significant advantage of thrust reversers is that they reduce the pilot’s reliance on the plane’s brakes. The brakes can only take so many uses since they are consumable parts, just like cars. The harder you ride the brakes, to more often they will need to be replaced. And the brake shop usually charges more for a 737 than it does for your Ford Fiesta.
The thrust reversers are part of the engines, and deploying them is a free braking system. With the help of lift spoilers on the wings, these three things–thrust reversers, brakes, and lift spoilers–can stop a huge airliner, traveling at 150 mph or more, in an impressively small distance.
Reverse Thrust Pushback
It is possible to slowly reverse the plane on the ground for a short distance on some jets. For example, a jet could theoretically push itself back from its gate. Once far enough back, the pilots could disengage the thrust reversers and begin turning to the taxiway.
But in reality, you seldom see this happen. At most airports, the ramp areas are congested with luggage and service carts and lots of personnel. Jet blast is powerful, and it can blow people or vehicles hundreds of feet across the tarmac, causing severe damage and injury.
FOD (foreign object debris) damage to the plane or engine is also a concern. When a turbine spins up, it ingests a massive amount of air and creates a powerful suction that can scoop up carts, luggage, and anything else. Once in the engine, even small items will cause severe and costly damage.
So few airports will allow a pilot to do a reverse thrust pushback or power back. But it’s possible to do, and still fun to play with on flight simulators.
How Does Reverse Thrust Work on a Turboprop?
Turboprops are jet engines connected to propellers. This type of powerplant is very common in large, high-performance airplanes designed for short or medium-range operations.
You’ll see turboprop airplanes operating for the regional airlines. Common examples include the Cessna Caravan, ATR 72, Dash 8, Beechcraft 1900, and Saab 340. They are very efficient to fly between 20,000 and 30,000 feet, where the cost of a turbofan airplane might be restrictive.
Since these planes get their thrust from a propeller, just like a piston-driven airplane, thrust reversers don’t work. But they still often have a system that produces the same effect.
High-performance airplanes like these all have adjustable-pitch propellers. Most small aircraft have props that change pitch so that they can be optimized for various flight profiles.
But some models of airplanes go one step further and have propellers that can reverse their pitches. The result is reverse thrust, which can back the plane up on the tarmac or help slow it down on the runway.
While most propeller pitch functions are controlled by moving the blue prop lever in the cockpit, reverse thrust or “beta mode” is achieved by moving the throttle all the way aft. It is only used during ground operations.