Not that there is a problem with the ticket he is holding. It's just that John is a COS - Customer of Size - and he is required to buy two tickets for the simple reason that he can't fit his sizeable bum into a single seat.

John offers to sit sideways but the check-in staff are adamant - the owners of big butts must buy two seats. To console himself, he heads for the nearest fast-food outlet where he assembles and ploughs through an impressive pile of burgers, fries and thickshakes, consuming sufficient food for four people. If John stays in the airline terminal long enough, he'll need to buy three seats.

Elsewhere in Airline USA, passenger Michael has just been told that he also is a COS, although this designation has nothing to do with his size.

Michael, rather, is a Customer of Smell whose body odour is so overpowering it has offended his fellow passengers on the flight from which he has just disembarked.

They have alerted staff to the presence of a COS and it will come as no surprise to find that Michael is not difficult to locate. Following their noses, the staff track him down and give him the sniff test.

Phew! Michael fails spectacularly, several staff members appearing to turn a pale shade of green as they sniff the air which comprises his personal space.

Someone has to decide whether he will be allowed to continue on the next leg of his journey. This task falls to a supervisor who takes one deep sniff, gags and makes her decision - Michael is definitely a customer of smell.

The airline cuts a deal with him. If he'll retire to the men's room, wash and put on clean clothes supplied by the airline's staff, he'll be allowed to continue his journey.

The staff aren't taking any chances; they also give him a free can of deodorant and seal his cabin baggage, which is also emitting an eye-watering odour, in a plastic bag. Finally Michael, not exactly smelling of roses but no longer reminiscent of last week's garbage, is allowed on board.