How an airport works day to day

A-CDM at airports: what TOBT, TSAT and TTOT mean

Behind every on-time pushback is a timestamp system: A-CDM. We explain the acronyms from SOBT to ATOT, the 16 milestones and why a jet sometimes sits ready at the gate and waits.

APU, ground power and PCA: how an aircraft gets power on the ground

Auxiliary power unit in the tail, ground power cable from the jet bridge, thick air-conditioning hose under the fuselage: how an aircraft is supplied with electricity, air and compressed air between landing and takeoff – and how to spot it from the fence.

Diversion: why flights are rerouted to an alternate airport

Every scheduled flight starts with a plan B in the tank. Which kinds of alternate airports exist, how fuel reserves are calculated, who decides on a diversion and which German airports suit as an alternate.

Aircraft de-icing: fluids, holdover time and de-icing pads

Orange clouds, a green film on the wings, queues at the de-icing pad: what happens during aircraft de-icing, why holdover time sets the pace of winter operations and where you can watch it best as a spotter.

ETOPS explained: long-haul with two engines and diversion airports

ETOPS governs how far a twin-engine airliner may stray from a suitable airport. History, minute tiers, fuel rules and what it means for spotters at diversion airports.

Airport capacity: declared capacity, movements per hour and runway systems

How many takeoffs and landings an airport can handle per hour depends mainly on runway layout, separation and mode of operation. Declared capacity, runway systems and examples from Frankfurt, Munich, Hamburg, Düsseldorf and London explained.

Runway numbers explained: what 25C, 08L and 36 mean at airports

A runway number is a rounded compass heading, and the letter after it shows the position in a parallel runway system. Here is how to read 25C, 08L or 36, and why BER and Cologne/Bonn renamed their runways.

Airport fire service: ICAO fire categories and crash tenders like the Panther

The length and fuselage width of the largest aircraft determine how strong an airport fire service has to be. Categories 1 to 10, extinguishing agents, response time and vehicles like the Rosenbauer Panther at a glance.

Airport charges explained: landing, passenger and noise charges

Landing charge, passenger charge, noise surcharge and parking fee: how airport charges are built up, who approves them, how they differ from taxes and security fees – and what you can see of them at the fence.

Why flights are delayed: delay codes, aircraft rotations and flow control

Almost half of all delay minutes in Europe are simply passed along. How rotations, delay codes and ATFM slots fit together and what that means for your planning at the fence.

Aircraft refueling: hydrant systems, fuel trucks and jet fuel logistics

Under the aprons of big airports lies a pipe network full of jet fuel. How hydrants, dispensers and fuel trucks work together, how refueling goes and how to recognize the vehicles at the fence.

Aircraft tugs: towbar, towbarless, Taxibot and maintenance tows

Without a tug, no jet moves backward at the gate. How towbar and towbarless tugs work, what the Taxibot does differently and why aircraft roll across the apron at night with their engines off.

Aircraft maintenance explained: line maintenance, A-check, C-check and D-check

From the walkaround before departure to the heavy overhaul in the hangar: how airliner maintenance is structured, who is allowed to carry it out and how you can tell as a spotter that an aircraft is currently in the shop.

Follow-me vehicles: what they do and where to see special ones

Yellow car, illuminated sign on the roof, a jet in tow: follow-me vehicles guide aircraft over unfamiliar taxiways, secure construction sites and inspect runways. Duties, identifying features and well-known examples from sports cars to the Trabant.

A suitcase’s journey: baggage conveyor systems, screening and loading

Between the baggage belt and the cargo hold are barcode readers, multi-stage screening, sorters and containers. How a suitcase finds its way through the airport and what you can see of it on the apron.

ILS approach explained simply: how aircraft find the runway safely in fog

Two radio beams, a 3-degree path and clear weather minimums: how the instrument landing system guides aircraft to just short of the runway – and how you use that knowledge at your spot.

Measuring aircraft noise: monitoring stations, noise protection zones and noise quotas

Monitoring stations record every flyover, protection zones are calculated – and quotas decide which types may fly at night. How measurement, law and flight schedule fit together.

Night flight bans in Germany: what applies at which airport after dark

There is no nationwide night flight ban – every airport has its own rules. Core hours, shoulder hours, delay rules and the airports where night is when operations really start, at a glance.

Runway lighting explained: approach lights, PAPI and the color codes at the airport

Every color at an airport at night has a fixed meaning. From approach lights and PAPI to stop bars and taxiway lights: the color code at a glance – and what it tells you at the fence.

Runway safety: RESA, EMAS and protection against overruns

Beyond every runway end lies a protection zone in case an aircraft doesn’t stop in time. How runway end safety areas are built, why the US relies on 300 meters and how EMAS beds of crushable material stop jets.

Pushback explained: how aircraft get backed out of the parking position

Why jets don’t taxi backward on their own, how towbar and towbarless tugs work, what the person on the headset says and how to tell at the fence that a pushback is about to begin.

Understanding taxiways, holding points and signs at airports

Why is the taxiway called N3, what does the red sign with 25C mean and why does the jet stop at four yellow lines? The logic behind taxiways, holding points, signs and lights, explained clearly.

Airport slots explained: coordination, the 80/20 rule and slot value

A slot is permission to take off or land at a congested airport at a particular time. How coordinators allocate them, why airlines defend them with the 80/20 rule and what that means for the schedule you see at the fence.

Turnaround: how aircraft ground handling works at the gate

Between landing and the next departure, more happens at the gate than you can see from the observation deck. The sequence, vehicles, time windows and the rules behind the turnaround – explained for spotters.

Bird strikes explained: hazards, deterrence and the Hudson landing

Why birds and aircraft collide mainly near the ground, which parts are most at risk, how airports counter it with habitat management and deterrence – and what cases like US Airways 1549 taught.

Gates, boarding bridges and remote stands: how parking positions are assigned

Why does the A380 always park at the same pier, while the regional jet sits out on the apron? A look at stand types, size classes and the logic behind stand allocation.

Water salute (Wassertaufe): when airport fire crews greet aircraft with fountains

Two fire trucks, an arch of water over the taxiway, an aircraft in the middle: what is behind the water salute, on which occasions it happens, what can go wrong and how to catch it as a spotter.

Airport winter operations: runway clearing, braking action and snow plows

Plow convoys, deicers instead of road salt and a runway condition code from 0 to 6: how an airport keeps its runways open in winter – and what that means for your spotting day.

Wake turbulence and separation: why there is extra room behind the A380

Every aircraft trails two invisible vortices. How they form, which categories air traffic control uses for separation and what you can see and hear of it as a spotter.