The U.S. Federal Aviation Administration (FAA) has ordered an inspection of more than 1,000 Boeing twin-engine narrow-body 737 airliners for a potentially faulty part on the tail plane, which could potentially cause loss of control.
The airworthiness directive (AD) issued by the FAA prompts all airlines and operators to replace the pins, which are used to attach the aircraft horizontal stabilizer with improved pins.
Also known as the tail plane, the horizontal stabilizer controls the up-and-down movement of the nose.
This decision comes amid concerns that the pins could break, as they did not have sufficient anti-corrosive coating.
FAA stated that the agency is issuing this AD to prevent premature failure of the attach pins, which could cause reduced structural integrity of the horizontal stabilizer to fuselage attachment, resulting in loss of control of the aeroplane.
The inspection has been ordered following reports of an incorrect procedure used to apply the wear and corrosion protective surface coating to attach pins of the horizontal stabilizer rear spar.
The directive comes into effect May 20, 2013 and provides airlines with various compliance times based on the age of aircraft and other factors.
Around 1,050 airplanes, including 737-600, 737-700, 737-700C, 737-800, 737-900, and 737-900ER series, flown by the US carriers are affected by the directive, the FAA said.
It is estimated that the cost of inspecting an aircraft and replacing defective pins could be up to $10.1m across the fleet, or up to $9,627 for each airliner.
Aviation authorities issue airworthiness directives on a regular basis in order to address defects on jetliners.
The latest directive builds on recent FAA safety directives that affected various flight-control panels on the tails of most of the 737s.
Recently, FAA ordered Boeing-recommended fixes to prevent severe vibration that is likely to pose a risk of structural failure of the horizontal stabilizer or another section of the tails of 737s.
Earlier this year, the agency extended proposed inspections and fixes over improper installation of certain bolts used to attach horizontal stabilizers to 737 jetliners.