The U.S. Federal Aviation Administration (FAA) issued an emergency airworthiness directive on the 24th, requiring an emergency inspection of about 2000 Boeing 737NG and 737classic airliners registered in the United States. The reason is that the corrosion of the air check valve of the above-mentioned aircraft may cause the engine to stop in flight.
The FAA said that it has received four reports of engine stoppage in flight for 737NG and 737classic aircraft so far, so it has made emergency inspection requirements. The objects of inspection are passenger aircraft that have been parked for 7 days or more continuously, and those that have flown less than 11 times since re entering flight.
The FAA has warned that if the fifth stage check valves of both engines of the airliner are corroded, it may be stuck in the open position, resulting in a complete loss of power and failure to restart the engine.
The aviation regulator ordered that once corrosion is found on the check valve, the airline operator must replace the key component before the aircraft is put into service again.
Boeing responded later that day that the outbreak of the new crown epidemic led to reduced travel demand, and many airliners were sealed up or used less, check valves are more vulnerable to corrosion..
At the same time, Boeing said it has recommended that aviation operators check the aircraft involved in the directive, and if problems are found, Boeing will provide assistance in terms of maintenance and replacement of check valves.
According to the associated press, airliners of major U.S. airlines usually fly several times a day, but after the outbreak of the new crown epidemic, a large number of airliners have been grounded; with the slow growth of passenger travel demand, some airliners have been put into operation again.
The FAA did not release details of the four air parking reports. Alaska Airlines disclosed one of the incidents later on the 24th. The airline operator said in a statement that one of its airliners flew from Seattle, Washington, to Austin, Texas, on July 15, when an engine suddenly stalled and the plane finally made an emergency landing at Austin Airport.
Alaska Airlines said it had replaced the aircrafts engines and had checked the engines of six of them in accordance with FAA instructions.
American Airlines, United Airlines and Southwest Airlines said on the 24th that there was no engine flameout associated with the air check valve on their aircraft. Four American Airlines aircraft will be inspected and 28 United Airlines will be inspected.
Delta said it would inspect 20 of its planes, but did not say whether there had been engine stalls.
Several media reported that the FAA emergency airworthiness directive is another impact on Boeing. The total number of people killed by Boeing airlines and Ethiopian Airlines in March 2018 was 346. The series of airliners were then grounded around the world and stopped production in January and resumed production in May.
FAA director Steve Dixon admitted in June that the FAA made a mistake in its regulation of Boeing for the 737max. (Zheng Haoning) (special feature of Xinhua News Agency)
Source: responsible editor of Xinhua News Agency: Wang Fengzhi_ NT2541