Ryanair tail fault sparks global alert

Both the US Federal Aviation Administration and Boeing, the maker of the Ryanair 737-800 airliner, issued alerts after a part on the Ryanair plane failed.

The FAA, in an airworthiness directive (AD) warned: "This condition, if not corrected, could result in a loss of aircraft control and structural integrity."

The Ryanair plane was "in the effectivity range of this AD," the Air Accident Investigation Unit report, just released, said.

A Boeing spokeswoman said shortly after the incident that the safety order affected about 600 aircraft in use worldwide.

The Ryanair plane was on its way from Eindhoven to Madrid on March 1, 2010, when the crew noticed airframe vibration. They diverted to Charleroi Airport, Belgium, where the plane landed normally.

During an inspection, a left hand stabiliser tab control mechanism was found to be damaged.

It was decided that further inspection and repair/maintenance was required.

Tool

The root cause of the problem, "bearing swage wear because of workmanship escapement and improper tool usage during component manufacture," was identified, the just released AAIU report said.

Boeing and the FAA "recognised the gravity of the situation and took immediate action," the report added.

As part of the manufacturer's investigation, it recommended that Ryanair carry out inspections of 11 aircraft of the same type. Boeing also received a second report, from a different airline operator, of a severe elevator vibration event "due to fractured aft attach lugs of the elevator tab control mechanism".

The FAA later issued other airworthiness directives prescribing new inspection requirements.

Boeing said it was re-designing the tab mechanism to address the problems.

The AAIU report said that while damage to the Ryanair aircraft was minor, it was of a serious nature.

Because of the actions already taken by Boeing and the FAA, the AAIU said in its report that its investigation did not sustain any safety recommendations.

mlavery@herald.ie