50 minutes ago Theo Leggett Transport Correspondent BBC Step on to the tarmac at any major airport around the world, and you'll notice an unmistakable smell. A slightly sweet, oily scent, redolent of old workshops or antique paraffin lamps. It is as much part of the travelling experience as lukewarm coffee and queues at passport control. It is, of course, the pervasive smell of jet fuel. That pungent aroma has become a lot more expensive in recent weeks. The price of jet fuel has risen dramatically on international markets since the start of the conflict in the Middle East. There are now concerns that unless the Strait of Hormuz reopens soon, there could be physical shortages in some areas in the coming months. Many airlines have already pushed up ticket prices as the cost of flying has increased, and some have trimmed their capacity. Unless extra supplies can be found, a lack of fuel could lead to further disruption and cancellations heading into the peak summer holiday period.…