Taxiing is the movement of an aircraft on the ground under its own power, excluding takeoff and landing. When your plane lands and slowly makes its way to the gate, or when it leaves the gate and heads toward the runway before departure, that’s taxiing. It’s a distinct phase of flight with its own rules, infrastructure, and safety procedures.
How Taxiing Works
An aircraft taxiing uses its engines to move forward, but pilots don’t steer with the same controls they use in the air. On the ground, steering comes from two systems: rudder pedals and a device called a tiller. The rudder pedals, which control the tail fin during flight, also connect to the nose wheel on the ground. Pressing the left pedal turns the aircraft left; pressing the right turns it right. Pilots can also apply brakes on one side to tighten a turn.
On larger jets, a small steering wheel called a tiller is mounted on the cockpit’s side wall, usually on the captain’s side. The tiller gives much greater turning ability than the rudder pedals alone, which is essential for navigating tight corners on taxiways. In newer aircraft, both the tiller and rudder pedals work together, though the pedals offer reduced steering range. Once an aircraft accelerates during takeoff and the nose wheel lifts off the ground, it automatically centers itself, and steering shifts entirely to aerodynamic controls.
Pushback vs. Taxiing
Most gates at commercial airports are “nose-in,” meaning the aircraft parks with its nose facing the terminal. Since planes can’t reverse under their own power, a specialized ground vehicle called a tug pushes the aircraft backward until it’s clear of the gate area and pointed in the right direction. This is called pushback, and it’s not considered taxiing. Taxiing officially begins once the tug disconnects and the aircraft starts moving forward on its own engine power. For departing flights, the taxi phase runs from the parking area to the runway holding position. For arriving flights, it runs from the runway exit to the gate.
Helicopters Taxi Differently
Helicopters and other vertical-takeoff aircraft can “air-taxi,” which means hovering just above the ground and moving at speeds typically below 20 knots (about 23 mph). This counts as a separate category from standard taxiing because the aircraft isn’t rolling on wheels along the surface.
Following the Yellow and Blue Lines
Airports are essentially road networks for aircraft, with their own lane markings, signs, and traffic lights. All taxiway markings are yellow. A single continuous yellow line down the center of a taxiway serves as the centerline that pilots follow, much like a lane divider on a road. Double yellow lines along the edges define where the taxiway ends and the shoulder begins.
The most critical marking on any taxiway is the runway holding position: four yellow lines (two solid, two dashed) stretching across the full width of the taxiway. The solid lines face the pilot, signaling “stop here.” Crossing this line without permission from air traffic control is a serious violation, because it means entering an active runway.
At night or in low visibility, lighting takes over. Taxiway edges are outlined with blue lights, while green lights mark the centerline. Yellow lights serve as warnings: steady yellow clearance bars mark holding positions, and flashing yellow runway guard lights alert pilots that they’re approaching a runway intersection. When exiting a runway onto a taxiway, pilots follow lead-off lights that alternate green and yellow, starting with green, to guide them safely clear of the runway environment.
What Pilots Hear From the Ground Controller
Once an aircraft is ready to taxi, pilots contact ground control (a separate frequency from the tower controller who handles takeoffs and landings). Ground control issues a taxi route, essentially turn-by-turn directions using taxiway names (letters like Alpha, Bravo, Charlie) and specific instructions about which runways to cross or avoid.
A typical instruction sounds like: “Taxi via Charlie, hold short of Runway Two-Seven.” “Hold short” means stop before reaching that runway and wait for further clearance. Pilots must read back hold short instructions to confirm they understood. At busy airports, “progressive taxi” instructions provide step-by-step guidance, especially useful during construction, closed taxiways, or poor visibility when the route isn’t visible from the control tower.
Another common instruction is “line up and wait,” which tells a pilot to enter the runway and stop in position for takeoff, but not to begin the takeoff roll until cleared. Controllers are prohibited from issuing conditional taxi instructions based on moving traffic, such as “cross behind the landing 737,” because these create ambiguity and increase the risk of collisions.
Why Taxiing Is a High-Risk Phase
Taxiing may look routine, but it accounts for a significant share of aviation safety events. A runway incursion, defined as any unauthorized presence of an aircraft, vehicle, or person on an active runway, often starts with a taxiing error. These range from Category D (an unauthorized presence with no immediate danger) to Category A (a collision narrowly avoided). Common causes include pilots crossing a runway without clearance, vehicle operators entering taxiways without authorization, and controller errors that put two aircraft too close together.
To reduce distractions during this phase, regulations require a “sterile cockpit” during taxi. This means the flight crew cannot engage in any nonessential conversation or activity. No casual chat, no paperwork unrelated to the current operation, no announcements that can wait. Flight attendants are briefed on this rule so they avoid contacting the cockpit during taxi unless there’s a safety issue. At busy airports where taxi times can stretch to 30 minutes or longer, maintaining this discipline requires additional coordination between the cockpit and cabin crew, especially when the aircraft stops for extended periods and passengers start getting restless.
Fuel and Environmental Costs
Taxiing burns a surprising amount of fuel, particularly at large airports where the route from gate to runway can take 20 to 40 minutes. A standard twin-engine jet like the Airbus A320 burns fuel from both engines the entire time it’s on the ground. To cut costs and emissions, many airlines now use single-engine taxi procedures: shutting down one engine during taxi and running only the other. This simple change reduces fuel consumption and emissions during ground operations with no meaningful impact on safety or schedule. As pressure mounts on airlines to lower their carbon footprint, single-engine taxiing has become one of the most practical, widely adopted fuel-saving measures in commercial aviation.