Boeing 737 operators are being ordered to check elevator control tabs after an aircraft diverted following severe elevator vibration and extensive damage to its tab control system.
The vibration resulted in rapid wear and subsequent failure of the attachment lugs, prompting an emergency airworthiness directive from the US FAA which has also been highlighted by the European Aviation Safety Agency.
Boeing issued a service bulletin on 12 March containing procedures for a detailed inspection of the inboard and outboard aft lugs, intended to detect spacer movement and other discrepancies in the tab control mechanism.
The directive, which covers 737 variants from the -600 upwards, requires certain airframes to be inspected within 12-30 days.
It says the inspection amounts to "interim action", adding that the results will "enable the manufacturer to obtain better insight into the nature, cause, and extent of the issue, and eventually to develop final action to address the unsafe condition".
While the directive does not specifically identify the initiating incident, the FAA has reportedly confirmed that it involved a Ryanair 737-800 which diverted to Brussels earlier this month while performing an Eindhoven-Madrid service.
Source: Air Transport Intelligence news
