FLT Lt Si Oakley and his colleague Flt Lt Paul Summers are two of the RAF's rising stars.

They may be young - aged 30 and 27, respectively - but are experienced pilots, who have seen and done more than most people could imagine.

But after hundreds of hours of flying, these two captains are trying their hand at one of the toughest tasks expected of a modern pilot - taking on fuel while still in the air.

Air-to-air refuelling is a crucial task in the modern RAF, and is one of RAF Brize Norton's main functions - its aircraft being at the sharp end of operations in Iraq and Afghanistan, where they keep the Air Force's fast fighter jets in the sky.

But while it is a skill to supply fuel while flying at 20,000ft, it is an altogether tougher feat to actually take fuel on. Both men are practising the technique while taking part in a joint exercise between the RAF and the Army in Northern England.

The exercise, codenamed Swift Panther, involves supplying fuel to a Hercules transporter and Harrier, Tornado, and Jaguar jets, engaging enemy militants from the imaginary country of Umberland on the ground. It also allows them to take fuel on from another VC-10 from Brize Norton.

The exercise takes place over the North Sea, east of the Yorkshire town of Whitby. And considering this is the East Coast in March, conditions could not be better. The sun is shining, turbulence is low, and visibility is near perfect.

"This is the best bit of the job," says Si, from Clanfield, who has just returned to Brize Norton from the Falkland Islands.

"It's big boy stuff! We have to be able to do this well, as we need to do it tactically in a war zone - often at night, with no lights, and in radio silence.

"The pilots of these fast jets may have been on combat missions, and might be nervous and wound up. It's our job to make it as easy for them as possible.

"Having said that, there's a certain amount of luck involved in making the connection!"

For Paul, it is the realisation of a childhood dream.

Originally from Cambridgeshire, he says he spent hours as a boy looking up at the aircraft from nearby RAF Lakenheath, from his garden, dreaming that one day he would also be a pilot. He has been with the Air Force for eight years.

I wanted to be in the air force since I was a kid," he says. "The job is great. I have spent a lot of time away from my family, but I get to do stuff like this!

"We go all over the world, to lots of nice places - like Brunei, Malaysia, and the United States - as well as lots of not so nice places - like Basra!

"I have been a captain for one year, after three years as a co-pilot. It's really good, though challenging.

"However, the good times of swanning around the world have gone. It's a little more serious now. We are more stretched, and you've got to be aware of what you are letting yourself in for. Though, people that want to join the RAF will do it anyway."

Passing on instruction to the trainees is Flt Lt Dave Hamilton. An experienced hand at air transport and fuelling, the 56-year-old from Shrivenham joined the RAF in 1972, after leaving Loughborough University, where he was an Air Cadet.

And he admits he loves the job as much today as when he first took to the skies.

"I really enjoy it," he says. "It just gets better and better. I think we have got the best job in the Air Force."

He know spends much of his time passing on his skills to a new generation of captains.

He adds: "Flying is fantastic. One of the attractions of what we do, is that it's not a Monday-to-Friday, nine-to-five office job."

Indeed, the job has taken him everywhere from Afghanistan to Iraq - where he was involved in operations during the first Gulf war. He has also spent four months in the Falklands.

But at 56, he admits it will soon be time to move on. "I am a bit old for the air force," he smiles. "I will be leaving in a year's time."

For many airmen, that involves taking up a position with a civilian airline - a job with more regular hours, but, arguably, far less excitement.

Of course, it takes more than just a pilot and co-pilot to keep a state-of-the-art aircraft in the sky. Performing vital roles in the cramped cockpit are a navigator and an engineer. Today's engineer is Master Engineer Al Hayton, whose key role is to move fuel around the VC-10's tanks, keeping the aircraft stable.

Providing navigational support is Nav Flt Lt 'Big' Vern Stevens, a 47-year-old, larger-than-life airman, who has been in the RAF for 30 years.

A quick-witted man, with a legendary sense of humour, 'Big Vern' has no doubt what he likes most about the job: "The pension!," he jokes.

"When you are young, it's about seeing the world, the 'esprit de corps', and the lifestyle. But at my age, it's the pension. But I wouldn't be here if I didn't enjoy it."

But the experience of life in the RAF is best summed up by the aircraft's cabin supervisor, 39-year-old Corp Col Coleman, from Carterton, who said: "There is nothing more rewarding or satisfying.

"The job, and the RAF as a whole, is ever changing. You can never predict what is going to happen. One of the most mundane tasks can turn into the best thing you've ever done!

"There is nothing else like it!"