A helicopter carrying Princess Anne was set down moments after take-off in a "minor" safety scare, it has emerged.

The pilot reacted as the craft hovered above the ground when a cockpit warning light came on, indicating a possible gearbox problem.

An engineer was called and it was fixed really quickly

Buckingham Palace spokesman

The scare happened as the Princess Royal left an official engagement in Burntwood, Staffordshire, on Tuesday after opening a �7m leisure centre development.

The helicopter warning system detected tiny particles in the gearbox, Buckingham Palace said.

"The princess was not in any danger," a spokesman went on.

"It was just one of these things that happens when a light comes on to indicate a minor problem.

"An engineer was called and it was fixed really quickly."

After the emergency landing the princess used a car to get to her next engagement.

The helicopter was used on Wednesday for official engagements with the Earl and Countess of Wessex in Scotland, the Palace spokesman added.