Boeing 737 operators have been told to check the elevator control tabs in 600 New Generation planes after an incident involving a Ryanair flight from the Dutch city of Eindhoven earlier this month.

The United States Federal Aviation Administration (FAA) ordered the checks after the Ryanair flight had to be diverted to an airport in Belgium when it developed a severe vibration problem. The elevator control tab is located on the horizontal part of the tail, and enables a plane to rise and descend.

Evert van Zwol, president of the Dutch pilots' association, says there is no cause to worry about flight safety because the problem has been discovered on time.