It's the winter of 2019, and the airport is having its busiest year to date. This is Heathrow before lockdown, where the Aviation Police are on the front line to protect Heathrow, and officers Terry and Dave return.

Returning to Britain's busiest airport with the familiar face of airside officer Ian, who has a close shave out on the runway. Veteran Border Force officers Glen and Amarjit hunt down smuggled cargo, and there's a new engineering kid on the block.

It's a day like no other, with one octogenarian forcing herself into the country under the watchful eye of Passenger Experience Guru Demi. Terminal 4 turns blue, and airside Hugh has a potential environmental mess on his hands.

Heathrow's heroes deal with the UK's worst winter storms. Whilst winds rage out on the airfield, and safety officer Rachel with airside Ian go into battle with bins and royal birds, inside the terminal there's a bad smell in immigration.

Border Force Kat decides whether to allow a holiday-maker arriving with little money and a confusing story into the UK. Meanwhile in Terminal 3, meticulous Customer Service Agent Mr Sho is having issues with a 400-year-old Japanese tradition.

In the coloured lanes of customs and excise, we rummage through carry-on luggage on the lookout for secret stashes. Virgin Atlantic's punctuality record is put in jeopardy by a captain's bottle of water, and there is love, actually in the air.

It's all upgrades and upper class at Heathrow as Virgin's clubhouse manager Holly showers passengers with her VIP treatment Valentine-style, while officers Terry and Dave have to deal with an unhappy upgraded passenger.

At Britain's busiest border, officers Kat and Tracy help a student from India who's arrived with no fixed abode, while on the airfield, Airside Ian is ducking and diving on the runway. Terminal 4 welcomes an exuberant new ambassador.

At Heathrow's Terminal Four, new airline on the block Vietnam Airlines are battling baggage woes in the lead up to the holiday period. Rookie engineer Mo comes up with an ingenious solution to ensure no-one is stranded abroad without their luggage.

It's all smells at Heathrow's Terminal 3 with a new restaurant, and Border Force dog Jessie sniffing out thousands of pounds. Meanwhile, Airside Ian is ramping up his crow impersonations, and Demi prevents a cardiologist having a heart attack.

Answering the question of whether you could pick up someone else's boarding card and take a trip around the world. Plus, some plane-spotters await a rather rare sight.

There's something smelly in Cargo that Border Force have to get to the bottom of. Passenger Experience Manager Harry rushes to a gate that's had its door smashed in and King of Terminal 2 Demi has 700 passengers descend on him - one being a pop star.

King of the passenger experience, manager Demi, deals with some disgruntled passengers, check-in girls Carrie-Anne and Selina juggle love lives and baggage belts, and border force Bob questions a young Brazilian student.

The airport runs at capacity, and the king and queen of Terminal Two, Sue and Demi, cope with the extra load from a closed Gatwick. Meanwhile, border force Bob is back, doing what he does best, protecting Britain's biggest border.

Border Force Bob juggles visas with a circus performer, whilst Security Officer Estefania investigates an oddly shaped object. There's also drama in Terminal 3 for Passenger Experience Manager Harry as he deals with a medical emergency.

Flying into Heathrow are an endangered parrot and a polar vortex. Whilst Officers Dave and Terry hunt for a wanted man gone missing on a plane, airside Ian and slicker-for-the-rules Steve battle snow in a blizzard to keep the runways open.

Dairy, drugs and dogs headline the visit to Heathrow. On the airfield, Airside Ian goes for a promotion, whilst inside the terminals Queen of T2 Sue saves a musician from missing her concert, wile there's a serious breach in security.

Landing at a hectic Heathrow is new Border Force Officer Rob, who is investigating job scams. Meanwhile, the grass is in desperate need of a trim, and we meet duo Sophie and Rachel, who are raving about airside safety.

Back with the colourful characters of Britain's Busiest Airport and it's as frenetic as ever. The runway is closed, Heathrow's Starsky and Hutch cordon off a plane full of passengers, and Airside Ian turns detective.

Passenger Experience Manager Demi deals with a medical emergency involving all the emergency services, Border Force Rob returns to cross-examine unsuspecting passengers arriving into the UK, and Buggy Driver Carlo is all loved up.

A five-star airline gives a top tier performance all about baggage. Plus, Border Force Rob deals with a frozen chicken trying to enter the country, and there's a surprise for passengers flying across to Heathrow's number one European destination.

An arresting episode greets viewers this time as Heathrow's boys in blue dash to the gate. Plus, Queen of Passenger Experience Sue sorts out some gents, whilst out on the airfield, Airside Ian shows off his muscles.

It's a right royal romp at Heathrow Airport with VIPs oozing out of every terminal. Passenger Experience Manager Sue gets star struck, whilst in Terminal Four, hockey champions try using their gold medals for an upgrade.

It's midnight. Airside Ian checks Heathrow's airfield lights before the onslaught of half term. Drugs Dog Cole protects the Border, while officer Estefania pushes passengers through security with a unique handling method.

Passenger experience manager Demi deals with some disgruntled passengers, while check-in attendants Carrie-Anne and Selina tackle broken baggage belts. Elsewhere, Border force worker Bob has to decide whether he should let a young Brazilian student into the UK to visit his brother.

The King and Queen of Terminal Two, Demi and Sue, wrestle with a bare chested drunk, and back at immigration Kat and Bob come across a visitor whose reason for entering the UK does not add up.

The airport is busy as it is half term with rich Russian kids returning home from British boarding schools, and trouble arrives when the biggest mobile crane stops in the middle of a live airfield.

It is all things Eastern with the arrival of some special cargo, a potential people trafficker flagged to Border Force, and the polar vortex that battered Britain in March affectionately called the Beast from the East. Also, rookie Ian is back.

The Border Force pull over a Ghanaian businessman declaring £114,000 in cash, there is love in the air at the unlikely location of T5 arrivals when a blind date takes place and it is the end of an era on the airfield for chief trainer Simon.

Terminal 5 receives a very special visitor, leaving Buggy Driver Carlo starstruck. British Airways have a new robot on the airfield and Border Force release the hounds in search of dirty money. Last in the series.

Passenger Experience Manager Sue does her best to get a passenger to his connecting flight at Gatwick - 38 miles away.

Travellers face the challengers of transferring in the five-square-mile airport, with 200 gates and four terminals.

Problems arise when a flight to New York is cancelled. Meanwhile, snow and ice threaten to close the runways.

Heavy fog throws Heathrow into turmoil and new terminal manager Callum is faced with hundreds of angry and stranded passengers stuck overnight at the airport, while visibility has dropped to less than 100m on the airfield and safety officer Chris is forced to marshal planes. Manager Nilam reveals the secrets of one of Heathrow's most exclusive first-class lounges and dispatcher James and his team hunt around the terminal for late passengers for a flight to Pakistan.

An American airline has one of its busiest days as hundreds of people fly to the USA for Thanksgiving, while Heathrow employee Sunita helps a woman who has lost her two-year old daughter. Ground staff use measures to disperse birds from the runway to prevent any collisions with aircraft, resident paramedic Izzy treats a pregnant passenger suffering from serious abdominal pain who is due to fly to Brazil that day and British Airways employees prepare for the inaugural flight of their new £185 million aircraft the Dreamliner.

Storm Imogen causes chaos on the runways and in the terminals, with airside safety officer Simon keeping his eyes peeled for any potentially dangerous debris that could damage the landing planes. In Terminal 4, manager Sunita looks after dozens of passengers whose flight to Delhi has been cancelled, while trainee engineer Elliot prepares to get his hands dirty as he clears a blocked sewage pit - an essential part of the airport's operations that no passenger normally sees.

This episode follows Heathrow staff racing against the clock to process thousands of passengers arriving from 84 different countries. Airside Safety Officer Glenn and his colleagues work closely with Air Traffic Control to keep Heathrow’s two runways open and clear of debris. Meanwhile, staff from the Animal Reception Centre welcome a variety of weird and wonderful animals – from pet ferrets to a wild tiger. Inside the terminals, Heathrow staff deal with passengers including a man who is stuck living at the airport after being deported from Thailand, and a family whose young relatives have got lost in Arrivals.

This episode follows Heathrow staff struggling to turn around hundreds of arriving planes, and get them back into the air on time. Cleaners, ground staff and flight crew race to get the world’s biggest passenger plane ready for departure. Meanwhile Heathrow prepares to open a £2bn new terminal, and welcomes a very special royal guest. Airport duty manager Andy is called on to defuse a major international protest, and a team of workers battle the elements as they attempt to resurface the runway overnight in time for the first flight of the morning.

This episode follows Heathrow staff trying to process 100,000 departing passengers a day, and get their flights away on time. Dispatcher Callie and Ramp Manager Steve have their plans thrown into chaos by a passenger who disappears after checking on to their flight. In Security, Sundeep and his team have to search an unusually dressed traveller, and deal with a man who is unhappy about having his bag searched. Meanwhile, Heathrow’s extradition team ensures police suspects are put on departing flights, while paparazzi photographer Kate is on the lookout for celebrities flying through the airport.