The United States Federal Aviation Administration (FAA) has advised airlines in the US to inspect older Boeing 737s that have been mostly sitting idle for possible corrosion which the agency states could lead to engine troubles. In response, South Korean and Indian aviation regulators have issued their own orders for their carriers.
In a new emergency Airworthiness Directive (AD), the FAA stated that: “With airplanes being stored or used infrequently due to lower demand during the COVID-19 pandemic, the valve can be more susceptible to corrosion,” Boeing said in a statement.
The order could affect up to 2000 registered jets in the United States. It covers older Boeing 737 models including the 737 NG (-600 to -900) and the 737 Classic (-300 to -500) that have not been flown for seven or more consecutive days, or has flown less than 11 times since being put back to service.
Not covered in the safety advisory is the 737 MAX which have been grounded since March 2019 after two fatal crashes.
The safety advisory came after four reported incidents of single-engine shutdowns caused by engine bleed air valves that were stuck open.
Within the US, major airlines operating the aircraft type include United, Delta, American, and Southwest.
In response to the latest US FAA advisory, South Korea's Ministry of Land, Infrastructure and Transport issued its own order for the inspection of the aircraft in question.
South Korea's government order for the inspection of the 737 aircraft covers nine airlines in the country operating a total of 148 of the jets.
Among the prominent Boeing 737 operators in South Korea include Korean Air, Jeju Air, Jin Air, and T'way Air.
Joining South Korea's government issuing its order, India's aviation regulator Directorate General of Civil Aviation (DGCA) followed with its own.
India's government order affects three airlines operating the older 737s: SpiceJet, Vistara and AirIndia Express. Much of the combined fleet of 737 aircraft were grounded between late March to May as a result of the government imposed lockdown to contain the spread of COVID-19.