Plenty of people have flown from Heathrow Airport. In fact in 2017 there were 78 million passengers travelling through the airport, but few get to see life beyond the terminals.

Heathrow is changing behind the scenes, and we've been invited inside to see how they work.

The airport has changed a lot over the years, starting out as a 150-acre private aerodrome in 1930 and developing in to one of the world's busiest airports.

The airport had six runways, laid out in a "star of David" pattern, but now is down to two with controversial plans to build a third runway expected to be approved by Parliament in the coming months.

But Heathrow is much more than what the passengers see, with an estimated 78,000 people employed directly to work at the airport.

Remarkably, the way the airport ran barely changed in the modern era, but Heathrow Airport Limited, the company which runs the airport, has been making some changes behind the scenes, which reporter Qasim Peracha exclusively explored for Get West London .

Here's his first person account after gaining access to the areas completely restricted to the general public.

First I had to don a bright pink high visibility jacket and go through airport security and on to the airside. Beyond the discrete cabin just off Terminal 2 lies the airfield.

Being on the other side feels strange. Heathrow spans over 3,000 hectares and has to run like clockwork if it is to operate. Looking in the sky, you can see planes queuing up to land, while on the ground, there are always three or four aircraft waiting to take off.

It's 'clear why the whole operation can be jeopardised' by just 'light snowfall'

Each plane holds hundreds of passengers, who have been checked in, gone through security and had their luggage put on to planes. The planes have been cleaned and food is cooked and taken on board for the passengers while the plane itself is fuelled from pipelines running directly to each airport stand underneath the tarmac of the airfield.

There are so many moving parts to Heathrow that it becomes immediately clear why the whole operation can be jeopardised by something as trivial as some light snowfall.

Heathrow have been expanding their electric vehicle fleet

The most recent change at the airport is Heathrow 2.0, a sustainability strategy designed to cut emissions at the airport and create sustainable growth on the way to an expanded Heathrow.

Part of this is stuff like pre-conditioned air, a flourescent yellow hose which plugs in to a plane pumping cold air into it so that the planes don't burn fuel running their auxillary engine in its tail while it is parked on the tarmac for hours between flights.

The airport is also on a drive to go electric, and currently has one of the largest corporate electric vehicle fleets in the country. However, Heathrow continues to face criticism for air quality in and around the airport.

The latest announcement is that the airport is buying up to 200 new Jaguar I-PACE cars, fully electric luxury vehicles which are being released this year, to chauffeur passengers in and out of central London, in partnership with WeKnow Group.

Chancellor Philip Hammond welcomed the partnership between Heathrow and Jaguar

Emma Gilthorpe, Executive Director at Heathrow, said: "We are thrilled to be working with two British companies on this landmark initiative to support more sustainable transportation choices for our passengers.

"We will not compromise on our commitments to the environment and our local community and we remain focused on addressing the impact road vehicles have on air quality on the roads around the airport.

"These I-PACEs are the latest in a long line of initiatives we are taking to ensure that we do not force a choice between the economy and the environment – and that we can deliver benefits for both."

Within the vast airfield, several Nissan Leaf and Mitsubishi Outlander electric vehicles are stationed for engineers and airport operators to use. However the airport is also looking at making the airport-specific vehicles electric.

Almost all the baggage tugs at Heathrow, which transport your luggage between the terminal and plane, are electric and the airport are trialling four different electric buses which could be used to move staff and passengers around the airport.

Four electric buses are being trialled at Heathrow

British Airways has introduced a new way system to move planes away from the gates, replacing big, heavy, diesel-powered vehicles who push the aircraft down the tarmac with small, electric, remote-controlled Mototoks.

Used for short haul BA flights at Terminal 5, these machines are tiny compared to their predecessors and release no harmful gases into the environment.

'Once inside Heathrow, you come to appreciate it is like its own town'

A quick ride to the top of the airport's traffic control tower showed the real scale of the operation to cut emissions. Air traffic controllers are dealing with an average of 45 aircraft taking off and landing at the airport every hour, but that also presents a major challenge on the ground.

Planes taxiing to and from gates at the airport are a large source of emissions and ground traffic controllers must constantly me making sure the plane's engines are running for the shortest possible time.

Air traffic controllers have to deal with 45 aircraft movements every hour in Heathrow's crowded ground and air space

It's difficult work and requires maximum concentration, which means controllers only work for 90 minutes at a time before they have to take a break.

Once inside Heathrow, you come to appreciate it is like it's own town. It is certainly more than large enough to be one, and even has its own police station and fire brigade.

It's easy to ignore the amount of work that goes into making humans fly long distances. But handling over 200,000 passengers every single day is significant work.