Aviation knowledge: airlines, airports & history

How September 11, 2001 changed aviation security and air travel

Four hijacked airliners, a completely closed airspace and an industry in crisis: this look back shows which rules emerged after September 11, 2001, which airlines did not survive the fallout and why plane spotting changed too.

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.

Air Berlin: the rise and bankruptcy of Germany’s second-largest airline

From a Mallorca charter carrier in divided Berlin to Germany’s second-largest airline – and into insolvency in 2017. The story of Air Berlin with its acquisitions, fleet, liveries and the farewell flight to Tegel.

Fleet planning: how airlines manage orders, options, delivery slots and retirement

Between signing a purchase contract and the first scheduled flight, many years often pass. How firm orders, options, delivery slots, leasing and retirement work together – and how you can spot the effects at the fence.

Major airline bankruptcies in Europe: from Swissair to Alitalia

Grounding in Zurich, bankruptcy in Brussels, last flight to Tegel: how the big European airline collapses from 2001 to 2021 unfolded, what the cases have in common and where their aircraft, codes and brands live on.

Airline callsigns and their history: Speedbird, Shamrock, Dynasty and more

Speedbird, Shamrock, Dynasty, Cactus or Rooster: behind many airline callsigns are logos, predecessor airlines, hometowns or puns. How callsigns are assigned and what stories lie behind them.

Multi-brand strategies: why airline groups create subsidiaries and platforms

Eurowings, Discover, Transavia, Vueling, Malta Air, Jetstar: behind many airline names is a group with a plan. Why groups create subsidiaries and platforms, which models exist, which ones failed – and how to tell the operators apart at the fence.

AOC and operating license: what legally makes an airline an airline

A logo and aircraft don’t make an airline. Only an air operator certificate (AOC) and an operating license allow commercial flights. What the two documents regulate, who issues them and what you can read from them as a spotter.

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.