Hawks?

One of my hens has gone missing - completely gone, not a feather left!

 I have checked every where and the pen is still secure, no holes in the fencing etc..  I had thought a fox may have got her, but the dogs never made a sound and there would have been feathers left I'm sure. 

I have noticed a large hawk type bird in the area recently (I'm not big on bird types so don't know which type of hawk, just a big one with a massive wing span!).  Do you think it's possible the hen could have been lifted by a hawk?

what age and breed of chickens have you got? I doubt that a hawk would take an adult large fowl.

In the summer one of the many raptors from the woods beside the farm carried off an adult Sablepoot hen, not nice  

We're in the middle of a village, houses on all sides. 

I was listening to the radio today and a man was on saying he had sighted a buzzard pretty close to here, maybe it was the same bird - as I said, I'm not good at differentiating between the birds of prey, but a buzzard sounds like he could so serious some damage to a wee hen 

I saw a large owl scouting my ladies the other morning.  She waited until I went back inside and then flew overhead.  I don't think she could have carried them off though because the smallest is a leghorn and the others are Maran and bluebells.   

I reckon orchardlady is right its unlikely to be a B.O.P. Lost a quail last year, there was just a quail sized hole in the chicken wire with blood on it no feathers or anything. I was really angry with myself as i had a roll of weldmesh left over from making a chcken run but didnt get round to upgrading Dave the quails run.
There was a lot of debate afterwards with the neighbours, was it a ferret, a stoat? But in the end we settled on fox as most probable. After reading mythical tales of stoat armies attacking dogs, cows and people i was really in the stoat camp, but most of the time its a fox.
There is occaionally fox poo outside my chicken run in the morning, but the weldmesh on all sides keep them out. According to my elderly neighbour, who is up at all hours, mr fox pops by at 2am most mornings for the chance of an easy breakfast.
Just be vigilant now because whatever did it knows theres a free meal in your garden.

Sorry about your chook, but as a life long ornithologist I think it very unlikely to be a bird of prey. Though most British species would be quite capable of taking a hen, it is improbable that any would do so in the circumstances you describe (within a pen - therefore I assume quite a restricted space surrounded by mesh fence, between houses & in a village). Buzzard, Red Kite, and Peregrine have been mentioned - I would immediately rule out both Buzzard and Peregrine, as taking chickens from a village garden is just not their style. Buzzards prefer to hunt in open country and given the choice, would shy away from human habitation, besides, at this time of year food is plentiful and they are more likely to be 'worming' in the centre of a large field. Peregrines have a very specific style of hunting that would certainly not involve taking hens from gardens - again, their preferred food is plentiful at this time of year (wildfowl & waders including Lapwing / Golden Plover flocks). Red Kites are the largest raptor you are likely to encounter and could easily take a hen, AND would readily enter gardens to feed, BUT prefer carrion to live food and again, there's no shortage of this around at this time of year.
If I had to put my money on a bird of prey being the culprit, I would opt for Sparrowhawk. Gardens are certainly within their remit, and a large female hawk could easily kill a hen, but would possibly struggle to carry it off and would seek to dispatch it before doing so - leaving a lot of evidence in the way of feathers on the ground.
But to be honest, I think your silent killer is far more likely to have had four legs ....