'Mid-air drama' for Prince Charles and Camilla ahead of Hay Festival visit

The Prince of Wales and the Duchess of Cornwall's visit to Hay-on-Wye suffered an unexpected setback today after their helicopter was forced to make an emergency landing.

A technical fault saw the flight urgently diverted to Denham Aerodrome in Buckinghamshire just minutes after taking off from central London - meaning the couple arrived in Wales almost three hours late.

A spokesperson for the couple said: "The pilot carried out a controlled emergency landing after diverting to the airport."

Despite the unscheduled stop, the royal couple transferred to cars and continued on to the market town of Hay-on-Wye by road.

Onlookers say Charles and Camilla looked relaxed and happy upon arrival, and made no reference to their turbulent trip.

Their planned leisurely tour of the town had to be undertaken more quickly, with visits to its open-air food market, Hay Castle and local businesses.

They continued by car to the town's 26th Festival of Literature, which began its annual 10-day run today.

On the agenda was a visit to the festival's main bookshop which played host to the launch of a Reading Agency campaign.

The independent charity has linked up with the festival to feature a special Summer Reading Challenge.

The campaign aims to reach 750,000 four to 11-year-olds and inspire them to read six books during the long summer break.Both Charles and Camilla attended the launch, which included hundreds of primary school children.

After the festival visit the royal couple parted and the Prince of Wales went on alone to Cardiff to attend the Welsh National Opera's opening new production of Wagner's Lohengrin.