It’s a rare opportunity to get a flight in an air ambulance without the downside of being seriously ill – so I didn’t need asking twice to take up the offer.

Some of my colleagues presumed that I must have been in a helicopter at some point during my time as a soldier, but in fact I hadn’t. I went into the experience yesterday as a more-or-less total rookie and with an open mind – knowing only that I was to fly from Stevenage in Hertfordshire to North Weald, near Harlow in Essex, in the Essex & Herts Air Ambulance charity’s brand-new £6.5 million aircraft.

I arrive at Fairlands Valley Park in Stevenage at about 3.30pm to already hear the whirring of the helicopter’s rotors overhead, and a sizeable crowd of children and parents congregating beside the lake – school having just finished for the day.

After what seems like an age, the red-and-yellow beast – set to enter service next week – finally hones into view from behind the trees and comes in to land, blowing the grass in every direction.

All stand dutifully back until a figure in a navy-blue jumpsuit appears from the starboard side of the cockpit and signals to the crowd, at which the children stream towards the air ambulance like football fans at the end of a cup final.

The new air ambulance is going on a tour of Herts and Essex to celebrate 20 years of operations, and Stevenage is one of the first stops. A mob of kids, mums and dads form on each side of the air ambulance as paramedics Scott McIlwaine and Ben Myer sit by each door to answer questions and pose for countless photographs.

Essex & Herts Air Ambulance chief pilot Jim Lynch – the aforementioned figure in navy blue – meanwhile enjoys a well-earned rest from flying. A pilot with nearly 30 years’ experience, he himself flew the Italian-made AW169 helicopter back over the Alps to England.

“We have four pilots who look after the roster – two captains and two co-pilots,” Jim explains.

“I just love flying, and this job, working for the air ambulance, is one of the best jobs I’ve ever had.

“It’s all about getting the medics out to the patients as quickly and safely as possible, and this new air ambulance provides us with just that little bit more.

“It’s got a bit more space in the back for them to work, and there’s a refresh in the way they package the kit – there’s just lots of incremental changes that this helicopter gives us.

“If we’re going out to the coast, we can get there six or seven minutes quicker in this helicopter, and that could make all the difference.”

The two-engined AW169 machine is to replace one of the charitable trust’s two MD902 helicopters during a transition period over the next few months.

“It gives amazing performance,” says Jim, moving to how the change impacts on him as the pilot. “It’s got lots more toys, lots of screens, lots of pretty pictures – it’s got a lot more capability.

“Among other things, it’s got several modern computers that allow us to program it to tell it where exactly we want to go and help us in bad weather.”

After a short flight briefing I strap myself in facing forward on the starboard side, complete with headset and microphone, and at about 4.35pm we’re off. The rotors begin to spin, the aircraft begins to shake and in a second we are airborne – a crowd of onlookers’ camera-phones following us as we rise into the air.

We bank around and take a brief look at the lake out of the port-side windows before we fly out across Stevenage and towards Addenbrooke’s Hospital in Cambridge – where Jim says we will be stopping off before returning to the air ambulance base at North Weald. Scott sits in the cockpit with Jim, while Ben is with me in the back. Tony remained on the ground.

I’m a reporter first and foremost, and no formally trained photographer – but I point my Nikon camera out the window and get the best shots I can of the countryside passing below as we speed over IWM Duxford after no more than 10 minutes.

Sitting inside the surprisingly roomy aircraft, I’m able to get a better idea of what Tony had told me on the ground about how the new aircraft impacted on his work as a paramedic.

“I don’t know how they’ve done it, but they’ve created a very effective and quite large working space,” Tony had explained.

“I think that will enable us to make more interventions for the patients en route to hospital than what we’re currently able to do, and that ultimately will be better for our patients – we can spend less time with them on scene and get them to the specialist centres faster.”

All air ambulance paramedics must have prior experience in the traditional road ambulances or rapid response vehicles – Tony himself moved up to air ambulance work three years ago. Each helicopter call-out has a different timescale, but he says that they would aim to have even the sickest patients stablised and in air within about 20 minutes.

At 4.50pm we come in to land in a field near Addenbrooke’s Hospital in Cambridge, where Ben explains that there would usually be a land ambulance waiting to relay the patient on to hospital and into care within a few minutes.

After a quick photograph of the helicopter on the ground, we’re back in the air at 4.55pm and heading south towards North Weald – and just after 5pm I get some fine aerial shots of the extremely handsome Audley End House near Saffron Walden.

We pass over Stansted Airport a few minutes later, and shortly at 5.10pm we’re back on the ground at North Weald – where Jim, Ben and Scott happily pose with the new helicopter before I make my way home.

Though I had felt somewhat nauseous towards the end of my first helicopter trip, my co-passengers assured me that it was actually a remarkably smooth ride compared to the older machines.

Above all, the speed with which we were able to cover vast distances brought home just what a remarkable asset air ambulances are for our health services, and how vital they can be in saving lives.

Stops on the air ambulance anniversary tour over the next week include Redbourn Junior School today – Tuesday – the Heath Sports Centre in Royston tomorrow, Hitchin Boys’ School this Thursday, Buntsfest in Buntingford on Saturday, and Welwyn Rugby Club on Sunday.

Some stops are invitation only, while others are open to all members of the public. To find out more see helitour.ehaat.org and ehaat.org.