ECHO reporter Jim Entwistle spends ten hours with the Great North Air Ambulance Service and sees first-hand the vital role it plays.

The alarm sounds. Paramedic Paul Scott dashes across the office and snatches at the telephone. The room falls silent.

The rest of the helicopter crew put their cups of coffee on the table. As soon as Mr Scott starts to scribble notes on a pad, the crew are readying themselves for take-off from Durham and Tees Valley Airport.

The details are sketchy, but we are told that there has been a collision between a motorcycle and a van near Langdon Beck, in Teesdale, County Durham.

It is my second flight of the day, and I feel a twinge of excitement as we hurry across the runway to the helicopter.

Within minutes we are up in the air, and flying towards the incident. The evening has brightened up and the early evening sun casts long shadows over the purple, pitted moorland.

But as we approach the scene, the enjoyment of the flight dissipates and the situation suddenly becomes very real for me. The crew had worked on hundreds of such accident scenes before, but for me it is new and I have no idea what to expect.

We touch down on a grassy hillside overlooking the incident. The motorcycle is on its side, debris scattered across the road. A van is parked in a gateway a short distance from the bike, a large dent in its passenger-side door. A few witnesses mill around, concerned.

A man is lying in the middle of the road, with police officers and ground ambulance crews busying around him. As we make our way down the hill, I hear the man answer questions about his motorcycle, talking a little at first, but then not at all.

I feel horrendously out of place in an air ambulance uniform. A witness asks me to talk to the distressed van driver, who is sat in his vehicle, away from the wreckage. I am unable to tell them what to do, because I don't know, and I feel a little guilty for being there at all. The paramedics ask me to get a leg brace out of the helicopter and I am glad to get away from the scene.

The medics work quickly, the man has a serious head injury and it is critical that he gets to hospital as soon as possible. We are soon in the air again.

Inside the helicopter, every inch of space is utilised with every aspect of emergency care facilitated in a space no bigger than a broom cupboard. There is just enough space for two and a patient in the back of the helicopter, and in between Dr Dave Bramley and myself the man is being made as comfortable as possible. If the road crews had made the journey to hospital, it could have taken up to two hours.

Within 20 minutes we are approaching The James Cook University Hospital, in Middlesbrough and a group of ten medics are waiting on the helipad with a stretcher.

Within a minute of touching down, the man is in the emergency room surrounded by a team of trauma experts.

I leave at this point - the emergency room is no place for a bystander, and I have seen enough to know the man has been given the best possible chance of survival. I later learn he underwent surgery that night and remained yesterday in a critical condition.

But Dr Bramley said he might not have had a chance of survival had he not got to the hospital so quickly.

The crew of the helicopter take it all in their stride. They are keen to fly and desperate to help, but it is pilot Ian Mousette who points out the paradox between their love for the job, and the fact that lives are in jeopardy every time the helicopter is called out.

"I'm always keen to fly, but I realise that every time I go up in the air, it's because of someone's misfortune and it could end in someone dying," he says. "But I'm doing what I love, which is flying, and at the same time providing a benefit to the community."

The crew are justifiably proud of their job, and as an outsider looking in, the bond between the men and the helicopter is striking. It is not just an ambulance. In the majority of circumstances, the helicopter has a doctor on-board specialising in pre-hospital treatment. This means the helicopter is, in effect, taking the emergency room to the patient, a level of treatment that continues on the aircraft.

Equally, the service is not just about getting the patient to the hospital as quickly as possible, nor keeping the patient comfortable during transport, because while this is an important function of the helicopter, the crew often perform surgery at the scene, saving valuable time, and in many cases, saving lives.

The heroics of the aircraft crew have not evaded the attention of a BBC film crew, who, after a one-off show following the Cumbrian air ambulance team, realised the potential for a series and are now putting the finishing touches to their documentary.

Earlier in the day, the film crew needed some aerial shots, so we took what was perhaps the ultimate sightseeing trip of the region, taking in Teesside's Transporter Bridge, the ghost ships at Hartlepool, Newcastle's St James' Park, and the Angel of the North, in Gateshead, in a 90-minute flight. It is hoped the television series will raise the profile of the Great North Air Ambulance Service.

The organisation is a charity and relies on public support to remain in the air.

Before my day with the crew, I had been told what an important service the air ambulance provides; but when I came face-to-face with this pioneering frontline service, it struck me just how vital it is, and how reassuring it is to know that wherever you are in the region, the real Angels of the North are never far away.

If you are interested in volunteering for the Great North Air Ambulance Service, or would like to help with fundraising, call 01325-487263 or visit www.greatnorthair ambulance.co.uk