In the document, dated April 15, the agency said it had been informed of an “incorrect procedure used to apply the wear and corrosion protective surface coating to attach pins of the horizontal stabilizer rear spar.”
The parts will need to be inspected and, in problem cases, replaced “to prevent premature failure of the attach pins, which could cause reduced structural integrity … resulting in loss of control of the airplane.”
The notice did not mention any incident so far resulting from the faulty parts.
It stated that the “airworthiness directive,” issued in accordance with Boeing, will take effect on May 20 and “affects 1,050 airplanes of US registry.”
The 737, a single aisle jet is Boeing’s most popular model, with more than 10,000 planes sold.
An FAA spokesman told AFP the agency “occasionally” publishes such directives “that affect significant numbers of aircraft.”
Boeing was not immediately available for comment.
The affected planes include the 600, 700, 700C, 800, 900, and 900ER models of the 737.
The FAA estimates that the operation could cost as much as $10 million to US airlines, but a part of the cost could be covered by the manufacturer’s warranty.