Level 1 — Absolute Beginner

Something strange is happening in Europe. Someone is calling airports and saying there is a bomb on a plane. The planes are not carrying bombs. The calls are fake.

The calls started on Monday, 2 November. By Thursday, almost 30 flights had a bomb warning in one single day. Ryanair, Aer Lingus and Wizz Air all had flights with warnings.

When a pilot hears a warning, the plane must land. Police then search the plane. Every passenger must get off. So far, police have found nothing. There is no bomb on any plane.

Police do not know who is making the calls. Nobody has been arrested. People are angry because the fake calls waste time, cost money and frighten passengers.

a bomb

A weapon that explodes and can destroy things.

fake

Not real, made to trick people.

a threat

A warning that someone will hurt you or damage something.

a flight

A journey by plane from one city to another.

to land

To bring a plane down to the ground.

to search

To look carefully everywhere to find something.

a passenger

A person who travels on a plane, bus or train.

a hoax

A lie or trick that makes people believe something false.

Level 2 — Elementary

For one week in early November, airports across Europe dealt with a wave of bomb warnings that all turned out to be false. The first case was on Monday 2 November, when a Wizz Air flight from London Luton to Sofia received a warning in the air and landed instead in Budapest. Hungarian fighter jets went up to escort it.

The next day at least seven flights were targeted, and so was a cruise ship called the Crown Iris, which was carrying about 1,500 people towards Haifa. Ryanair was hit hardest, with four flights. By Thursday 5 November the number of threatened flights had grown to between 25 and 27, depending on which news organisation you read, across 16 countries.

The disruption was expensive and frightening. An Aer Lingus flight from Dublin to Rome, with 151 passengers and six crew, was sent to a French air force base in Normandy. A Ryanair flight from Stansted to Cork was emptied and delayed by 90 minutes before police declared the threat a hoax. In Dublin, the headquarters of the broadcaster RTE was also evacuated after a threat.

No explosive device has been found anywhere, and nobody has been arrested. Helen McEntee, Ireland's Minister for Defence, called the week "extremely concerning, what we've seen happen in a very short space of time". The EU transport commissioner, Apostolos Tzitzikostas, said that "any threats against civilians are unacceptable".

a wave

A large number of similar events happening close together.

to target

To choose someone or something to attack.

to escort

To travel beside someone or something to protect it.

disruption

A situation in which normal activity is stopped or delayed.

to evacuate

To make everyone leave a building or vehicle quickly for safety.

an explosive device

An object built to explode, such as a bomb.

a broadcaster

A company that makes radio or television programmes.

unacceptable

So bad or wrong that it cannot be allowed.

Level 3 — Intermediate

A week of false bomb warnings has exposed how easily a few anonymous phone calls and emails can paralyse European aviation. The pattern began on Monday 2 November with a mid-air warning on a Wizz Air service from London Luton to Sofia, which diverted to Budapest under escort from Hungarian Gripen fighter jets. By Thursday, Irish and international outlets were counting somewhere between 25 and 27 threatened flights in a single day, spread across 16 countries from Portugal to Finland.

The response each time is the same and it is costly. Crews notify air traffic control, military aircraft are sometimes scrambled, runways close, and police board the aircraft to carry out a full search. A Ryanair service from Dublin to Rome was escorted into Fiumicino by two Italian Eurofighters. An Aer Lingus flight carrying 151 passengers and six crew was redirected to Evreux-Fauville air base in Normandy. A spokesman for Warsaw Modlin airport summarised the outcome of every search so far in two words: "Nothing was found."

Attribution is the hardest part. European governments have spent two years accusing Russia and Iran of cheap, deniable sabotage, and both countries deny it. Some of the messages carried signatures designed to inflame: fake emails sent to Italian schools were signed in the name of Iran's Revolutionary Guard, which investigators do not treat as credible, while one Aer Lingus threat arrived in the name of a Russian online group. Anna Kruglova, who studies terrorism at the University of Salford, cautioned that "it could be anyone at all".

Analysts who track aviation risk read the randomness itself as the message. Rhys Jones of Osprey Flight Solutions told Reuters that "the lack of clear target state, airline or route indicates that general disruption to aviation operations is the aim". That is an uncomfortable conclusion for regulators, because a hoax requires almost no resources, carries little personal risk, and still forces an entire continent to behave as though the danger were real.

to paralyse

To stop something from working or moving at all.

to divert

To change the route of a vehicle so it goes somewhere else.

to scramble

To send military aircraft into the air very quickly in an emergency.

attribution

The act of deciding and stating who is responsible for something.

deniable

Done in a way that lets the person responsible claim they did not do it.

sabotage

Secret damage done to equipment or operations to cause harm.

credible

Able to be believed or trusted.

randomness

The quality of having no clear pattern, order or purpose.

Level 4 — Advanced

Few campaigns illustrate the asymmetry of modern disruption as neatly as the wave of hoax bomb threats that swept European aviation in the first week of November. The sequence opened quietly on Monday 2 November, when a Wizz Air service from London Luton to Sofia received a mid-air warning and put down in Budapest, shadowed by Hungarian Gripen interceptors. Within 72 hours the tally had swollen to somewhere between 25 and 27 threatened flights in a single day, by counts that varied between Euronews, ABC News and The Irish Times, touching 16 countries and at least ten carriers.

The procedural machinery that each call sets in motion is both necessary and ruinously expensive. Controllers must be notified, interceptors are occasionally scrambled, runways are closed, aircraft are towed to remote stands and swept, and hundreds of passengers are decanted onto buses while the clock runs. An Aer Lingus service carrying 151 passengers and six crew was rerouted to Evreux-Fauville air base in Normandy; a Ryanair flight from Stansted to Cork lost 90 minutes to an evacuation that police subsequently classified as a hoax; RTE's Donnybrook headquarters in Dublin was cleared, interrupting broadcasts, and Sky News confirmed it too had received a threat. Not one explosive device has been recovered, and no arrest has been announced.

Attribution remains stubbornly unresolved, and the ambiguity may be deliberate. European security establishments have spent two years cataloguing what they describe as Russian and Iranian hybrid operations, from arson to undersea cable damage, and both capitals routinely deny involvement. Several messages in this wave arrived wearing borrowed costumes: 279 fake threat emails sent to Italian schools were signed in the name of Iran's Islamic Revolutionary Guard Corps, a signature investigators regard as theatre rather than evidence, while one threat against Aer Lingus invoked a Russian online movement that, as Anna Kruglova of the University of Salford observed, has no record of operating abroad. Her verdict was bracingly agnostic: "it could be anyone at all".

What unsettles regulators is less the identity of the perpetrator than the economics of the tactic. Rhys Jones of Osprey Flight Solutions told Reuters that "the lack of clear target state, airline or route indicates that general disruption to aviation operations is the aim", a reading that treats the incoherence of the targeting as the signature rather than a flaw in it. A credible threat costs a telephone call; the obligatory response costs fuel, crew hours, airport capacity and public confidence. Until investigators can trace the origin of the messages, European aviation is left enforcing a security doctrine that is rational in each individual case and corrosive in aggregate.

asymmetry

A situation in which two sides have very unequal power, cost or risk.

interceptor

A fast military aircraft sent up to meet and inspect another aircraft.

to decant