The FAA has today issued an emergency airworthiness directive for around 2,000 Boeing 737 aircraft. The directive appears to cover the 737 Classic and NG range for any aircraft that have not flown in a week.
All ‘stored’ 737s to be checked
US-registered Boeing 737 aircraft have been issued with an emergency airworthiness directive by the Federal Aviation Administration (FAA) today. The directive, which covers all models of the 737 in service – both the Classic and the NG – applies to any aircraft which have not flown for seven consecutive days.
With much of the world’s fleet of aircraft in storage, this directive is expected to apply to around 2,000 aircraft. As the 737 MAX is currently grounded, it is not included in the directive, but it will apply to any Boeing 737 aircraft which is operational otherwise, namely the 737 NG (600 to 900 series) and 737 Classic (737-300 to 737-500 series).
The FAA says that the directive has been issued as a result of identified corrosion to the air check valves. Inspectors bringing some 737s out of service have noted this corrosion, which the FAA says could, in the worst-case scenario, lead to dual engine failure.
Details of the fault
The FAA has said in the directive that the notice was prompted by no less than four recent reports of engine shutdowns. These were determined to be caused by the air check valve being stuck in the open position as a result of corrosion.
The directive reports that flying the plane with this fault could result in compressor stalls and dual-engine power loss with no ability to restart. It says that every airplane that has been in ‘storage’ needs to be checked for the issue.
According to the FAA:
Any airplane that, for 7 or more consecutive days, has not been operated in flight is considered to be in “storage.”
The AD contains further details on how and when the inspection should be carried out and dictates that the valve must be replaced if the fault is found before revenue flights are undertaken.
This is a breaking story and will be updated as more details become clear. Please refresh for the latest update.
