91热爆

Suffolk's flat landscape has historically provided the ideal terrain for countless airbases - from World War One to the present day.

One of the biggest is RAF Mildenhall. Established by the Royal Air Force as a bomber base in 1934, it has been home to the United States Air Force since the early 1950s.

F15 fighter pilots in cockpit

The USAF's 100th Air Refueling Wing moved there in 1992 and now flies over 1700 missions a year from the base, clocking up over 7000 flight hours and burning a massive 拢42million of fuel in the skies above East Anglia.

91热爆 reporter Jozef Hall was invited to sample the mysterious world of air-to-air refuelling, gaining clearance to join a crew on one of their missions out of RAF Mildenhall.

$40million flying machine

The KC-135 Stratotanker, which carries gas to refuel USAF F15 fighter jets from nearby RAF Lakenheath,听is a massive two-storey converted Boeing 707.

The upper floor can carry both cargo and passengers, while the lower floor houses the fuel transfer system, known as a 'flying boom' with a shuttlecock-shaped drogue which trails behind the plane and is used to refuel craft with a receiver probe.

Pilots in the KC-135 Stratotanker

The whole thing is worth around $40million and is manned by just three USAF personnel - a pilot, co-pilot and the boom operator. On this trip, they're joined by a very excited Jozef, and Capt Ryan Ismirle, an F15 pilot.

This is a training mission and the refuelling of the F15s will take place at 16,000 feet above the North Sea Washes - it's essential to practice mid-air refuelling on a regular, often daily, basis.

Lining up mid-air

As they approach the designated area, the F15s arrive alongside, initially flying off the wing of the Stratotanker. An F15 moves into position behind and just below the Stratotanker's tail.

"It does feel like you could reach out and touch the nose of the F15," says Jozef in his commentary. "This is absolutely incredible."

The boom operator fine-tunes the nozzle for refuelling, making tiny movements from side-to-side until the position is perfect. "Straight in. There's no mucking around."

One after another the F15s line up, take on their fuel and fly off, making way for the next jet. "It's quite an ominous sight. A quick wave from the F15 pilot, hard bank to the left and they're off... show ponies!"

Jozef Hall and Master Sgt Charles Tubbs

As you can see from these pictures, what goes on above our heads on a daily basis requires more than just a steady hand and nerves of steel. You can see more stunning photographs of this refuelling mission in our gallery, and you can listen to Jozef's on-board report by clicking on the link below:

With the important stuff out of the way, Jozef joins Capt Ryan Ismirle, the F15 pilot, in the cockpit, as he explains what it's like to be on the receiving end of the fuel transfer.

"It's one of those tasks that we do, that if you don't practice it quite a bit, you get rusty, and when you get up there it can be quite dynamic," said Capt Ismirle. "A lot of things are involved. It could the weather, turbulence, things like that.

"So initially, starting out, it's two planes close together so you have to be very careful, very gentle with the controls to get yourself into the right position and maintain that.

"It's not an easy thing to do. It's almost like flying in formation but this guy is actually going to make contact with you."

Capt Ismirle explains that he's usually OK if he hasn't practiced refuelling for a fortnight, but if he leaves it for a month, it can be a bit more difficult to get it absolutely right.

"Keep in mind it's pretty basic stuff we're doing around here, but when you're carrying weapons on an aeroplane, external fuel tanks and such, all of a sudden you get into bad weather... well that's the sort of thing where doing it daily really helps.

F15 fighters prepare for refuelling

"And it's a really interesting perspective for me to see what these guys are doing. I've had difficult times when I've been trying to take gas, but I can see that these guys definitely have a tough job.

"You've got two jets moving in close proximity and they're responsible for putting that boom in the right spot without a lot of air. I've got a lot of respect for what those guys do."

Two-and-a-half hours later, and safely on the runway at RAF Mildenhall, Jozef asks the Stratotanker pilot, Capt Chris Callaghan, if this was a successful training mission:

"A good mission, yes. Successful. We got all of our training done and the receivers got all the gas they needed. Now we'll go and check we didn't hit any birds - at least, I didn't hear any!"

You can listen to Jozef talking to the Stratotanker crew from the cockpit of the plane by clicking on the link below, and check out our bird's-eye views of the mission in the photo gallery: