What Happens When a Plane Lands?

What Happens When a Plane Lands?

Watching from the terminal or the viewing areas around Prestwick, you see an aircraft touch down on Runway 12/30 and disappear behind buildings. A short while later, another aircraft pushes back and taxis out to the runway. But what actually happens in between? The answer is a carefully choreographed sequence called the turnaround — and at a busy airport, every minute counts.

This lesson walks you through the full process from touchdown to departure.

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Touchdown and Roll-Out

The aircraft crosses the runway threshold and the main landing gear makes contact with the surface. The pilots deploy reverse thrust (you can hear the engines roar louder for a few seconds) and apply the wheel brakes to slow down. On Prestwick's main runway (12/30, which is 2,986 metres long), there is plenty of room for most aircraft types to decelerate comfortably.

Once the aircraft has slowed to taxi speed — typically around 20-30 knots — the pilots receive instructions from Air Traffic Control (ATC) to vacate the runway via one of the taxiways. At Prestwick, aircraft commonly exit via Taxiway Juliett or one of the other connecting links depending on where they touched down and how quickly they stopped.

Taxiing to the Stand

With the aircraft now off the active runway, it taxis along one of Prestwick's main taxiways — Juliett, Romeo, or Sierra — following the yellow centreline markings and green taxiway centreline lights.

The pilots follow ATC instructions and read the airfield signs along the way. At Prestwick, the taxi from the runway to the terminal apron is relatively short, which is one reason the airport can achieve quick turnaround times.

As the aircraft approaches its allocated stand on one of the aprons (Prestwick has aprons designated A through H), the ground crew is already in position and waiting.

Parking on Stand

Arriving at the stand, the pilots use visual guidance to park precisely on the correct spot. At Prestwick, stands 1A through 4, 7, and 8 are equipped with AGNIS (Azimuth Guidance for Nose-In Stands) and PAPA (Parallax Aircraft Parking Aid) systems — these are light-based guides that tell the pilot whether they are left, right, or on centreline, and when to stop.

Other stands (5, 6, 9, 10, and 11) require a marshaller — a person on the ground using illuminated wands or bats to guide the aircraft in.

Once the aircraft is in position, several things happen almost simultaneously:

1. Chocks are placed against the wheels — these are wedge-shaped blocks that prevent the aircraft from rolling

2. The pilots set the parking brake and shut down the engines

3. Safety cones are placed around the aircraft to mark the safety zone

Ground Power and Services Connect

With the engines off, the aircraft needs electrical power for its systems. A Ground Power Unit (GPU) is connected — this is either a mobile generator driven to the aircraft or, on some stands, a fixed power supply built into the apron. This allows the aircraft to run its systems without burning fuel.

Similarly, an air conditioning unit may be connected in warm weather to keep the cabin comfortable while the doors are open, or warm air may be supplied in cold conditions.

Passenger Operations

The aircraft doors are opened and passengers begin to disembark. At Prestwick, most operations use stairs (sometimes called steps) rather than jet bridges, so you will see mobile stairways driven up to the forward and rear doors of the aircraft. Passengers walk across the apron to the terminal building.

While passengers are getting off from the front, baggage handlers are already opening the cargo holds underneath the aircraft and unloading bags onto belt loaders or baggage carts.

Cleaning and Catering

As soon as the last arriving passengers are off, the cleaning crew boards to prepare the cabin for the next flight. Seats are checked, seat pockets cleared, tray tables wiped, and the lavatories serviced. On a typical Ryanair turnaround at Prestwick — the airport's primary operator — this process is done at remarkable speed.

If required, catering vehicles pull up to load fresh food, drinks, and supplies for the outbound flight.

Refuelling

While passengers are disembarking and the cabin is being prepared, the aircraft is refuelled. At Prestwick, this is done using a fuel bowser — a specialised tanker truck that drives to the aircraft and connects a hose to the fuelling points, which are typically located under the wings.

Aviation fuel for jet aircraft is Jet A-1, a kerosene-type fuel. The amount loaded depends on the destination, expected weather, alternate airports, and required reserves. A Boeing 737 heading to Tenerife from Prestwick might take on around 15,000-18,000 litres.

Refuelling follows strict safety procedures — the aircraft must be bonded (electrically earthed) to prevent static discharge, and fire extinguishers are positioned nearby.

The New Passengers Board

With the cabin clean, the aircraft refuelled, and the new bags loaded into the hold, boarding begins. Passengers walk from the terminal across the apron and up the stairs. The gate agents and cabin crew manage the boarding process.

During boarding, the pilots are completing their pre-flight checks, reviewing the flight plan, checking the weather at the destination, and entering data into the aircraft's flight management system.

Pushback and Engine Start

Once all passengers are seated, doors closed, and the final paperwork completed (including the loadsheet, which confirms the aircraft's weight and balance), the aircraft is ready to go.

Because most aircraft cannot reverse under their own power, a pushback tug is connected to the nose gear to push the aircraft backwards off the stand and onto the taxiway. During pushback, the pilots start the engines — this is sometimes assisted by compressed air from a ground air start unit if the aircraft's own auxiliary power unit (APU) is not being used.

The chocks and ground equipment are removed, a final walk-around check confirms everything is clear, and the ground crew gives the all-clear signal.

Taxi and Departure

The aircraft now taxis under its own power back towards the runway, following ATC instructions. At the holding point, the pilots receive take-off clearance, line up on the runway, and apply full power.

The entire turnaround — from touchdown to being airborne again — can take as little as 25 minutes for a well-drilled low-cost carrier operation, though 35-45 minutes is more typical. For larger aircraft or long-haul cargo operations (Prestwick handles cargo from airlines like Cargolux), turnarounds can take several hours.

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Summary

Next time you watch an aircraft at Prestwick, see how many of these steps you can spot from the terminal or the perimeter.