How Do Pilots Find the Airport?

Imagine you are a passenger on a flight from Dublin to Prestwick. Your aircraft is cruising at 35,000 feet — nearly seven miles above the ground. The Ayrshire coast is somewhere below, but from that altitude, individual airports are invisible. So how does the pilot find Prestwick, line up with the correct runway, and land safely?

The answer involves a combination of navigation technology, air traffic control, and published procedures that together create a reliable, repeatable system.

The Three Eras of Navigation

Aviation navigation has evolved through three broad phases, and all three are still in use today:

1. Visual Navigation (VFR — Visual Flight Rules)

In the earliest days of aviation, pilots navigated by looking out of the window. They followed landmarks — rivers, railways, coastlines, towns — and literally found their way by sight. This is called Visual Flight Rules (VFR) flying.

VFR flying still happens today, particularly for light aircraft and helicopters. A private pilot flying a Cessna from Cumbernauld to Prestwick might follow the Ayrshire coastline and look for the runway. But VFR only works when the weather is good enough to see the ground.

2. Radio Navigation

Starting in the mid-20th century, ground-based radio beacons were installed to provide navigation guidance regardless of weather. These beacons transmit signals that aircraft instruments can interpret to determine direction and distance.

The key types of radio navigation aids are:

NDB (Non-Directional Beacon) — transmits a signal that an aircraft's ADF (Automatic Direction Finder) points towards. Simple but imprecise. Prestwick has an NDB with the identifier PIK on 355 kHz.
VOR (VHF Omnidirectional Range) — transmits a more sophisticated signal that tells the aircraft its bearing from the beacon. Much more accurate than NDB. The nearest VOR to Prestwick is TRN (Turnberry) at 117.50 MHz, located south of the airport.
DME (Distance Measuring Equipment) — works with VOR to tell the aircraft its distance from the beacon. TRN includes DME.
ILS (Instrument Landing System) — a specialised system that provides precise guidance for the final approach to the runway (covered in detail in the next lesson).

3. Satellite Navigation (GNSS/GPS)

Modern aircraft use GNSS (Global Navigation Satellite System), which includes the American GPS system, European Galileo, and Russian GLONASS. Satellite navigation provides continuous, highly accurate position information anywhere on the planet.

Today, most commercial aircraft use GPS as their primary navigation method, with radio beacons as a backup. Some modern approach procedures (called RNAV or RNP approaches) are designed entirely around GPS navigation and do not require any ground-based radio beacons at all.

The Journey From Cruise to Landing

Let us follow that Dublin-to-Prestwick flight step by step:

Step 1: En Route Navigation

At 35,000 feet, the aircraft is following an airway — a defined corridor in the sky, much like a motorway on the ground. Airways connect waypoints (named points in the sky defined by GPS coordinates). The aircraft's GPS and Flight Management System (FMS) automatically guide it along the planned route.

During this phase, the aircraft is under the control of Scottish Control, the area control centre that manages upper airspace over Scotland.

Step 2: Descent and Arrival

About 100-150 miles from Prestwick, the aircraft begins its descent. Scottish Control issues clearances to descend from cruising altitude. The aircraft follows a STAR (Standard Terminal Arrival Route) — a published route that funnels traffic from the airways towards the airport.

For Prestwick, many arrivals route via Turnberry VOR (TRN), a radio beacon south of the airport. The aircraft descends progressively, typically reaching around 6,000-8,000 feet by the time it reaches the Prestwick area.

Step 3: Approach Control

Scottish Control hands the aircraft over to Prestwick Approach (120.550 MHz). The Approach controller uses radar to see the aircraft's position and issues instructions — headings to fly and altitudes to descend to — that guide the aircraft towards the final approach path for the active runway.

This phase is called vectoring: the controller gives the pilot a series of heading changes ("turn right heading 090", "turn left heading 150") that gradually line the aircraft up with the runway.

Step 4: Final Approach

Once the aircraft is lined up with the runway and at the correct altitude, it intercepts the ILS (Instrument Landing System) beam. The ILS provides precise guidance — left/right of the runway centreline and above/below the correct descent path.

The aircraft descends steadily on the ILS glideslope, typically at about 3 degrees — which means descending roughly 300 feet for every nautical mile flown. At a groundspeed of 140 knots, the aircraft is descending at about 700 feet per minute.

Step 5: Decision and Landing

At 200 feet above the runway (for a standard Category I ILS approach), the pilot must be able to see the runway lights or markings. If they can see the runway, they continue to land. If not — if cloud or fog obscures the runway — they must execute a missed approach: climb away and either try again or divert to another airport.

Assuming the runway is visible, the pilot takes over visually for the final seconds of the approach, flares the aircraft (raises the nose slightly to slow the descent rate), and touches down.

Step 6: After Landing

The aircraft decelerates on the runway, exits via a taxiway, and taxis to its stand. The entire process — from starting the descent at 35,000 feet to parking at the gate — takes roughly 20-30 minutes.

Why This System Is So Safe

Multiple layers of redundancy make this system remarkably safe:

GPS navigation provides continuous position accuracy
Radio beacons provide independent backup
ATC radar independently verifies the aircraft's position
ILS provides precise landing guidance independent of GPS
Published procedures mean everyone follows the same routes and altitudes
Missed approach procedures provide a safe escape if conditions are not met

The system works in the dark, in cloud, in rain, and in conditions where a pilot cannot see anything outside the cockpit until the final moments of the approach. That is the power of instrument navigation.

Key Takeaways

Pilots use a combination of GPS, radio beacons, ATC radar, and published procedures to navigate
The journey from cruise to landing follows a defined sequence: airway, STAR, approach vectors, ILS, landing
Prestwick arrivals often route via the Turnberry VOR before being vectored to the runway
The ILS provides precision guidance for the final approach, even in poor visibility
Multiple redundant systems ensure safety at every stage