Boeing 737s need to be inspected.
The chief US aviation authority has issued an "emergency airworthiness directive" to any airlines operating Boeing 737 aircraft, including the Boeing 737-800 operated by Ryanair.
Airlines have been instructed to inspect certain parts of their aircraft, and replace them if necessary. The warning was prompted by four recent reports of single-engine shutdowns due to engine bleed air fifth stage check valves being stuck open.
"Corrosion of these valves on both engines could result in a dual-engine power loss without the ability to restart. This condition, if not addressed, could result in compressor stalls and dual-engine power loss without the ability to restart, which could result in a forced off-airport landing," the directive advises.
It is believed that the problem has arisen because the aircraft have not been flown regularly throughout the Covid-19 crisis, and are now at risk of sudden engine failure.
According to the FAA: "Any airplane that, for seven or more consecutive days, has not been operated in flight, is considered to be in 'storage'."
According to its website, Ryanair operates a fleet of over 450 Boeing 737-800 series aircraft. In 2015, Boeing noted that Ryanair was the largest customer of the 737-800 in the world. Aer Lingus mostly uses Airbus vehicles, as well as Boeing 757s.
The document can be read in full
here.
