The FAA has proposed an AD that will require all 6,000 Boeing 737NG aircraft in service in the U.S. to be retrofitted with beefed-up engine nacelles. The AD was issued after a couple of fan blade failure incidents on Southwest aircraft in which pieces of the nacelle pierced the fuselage of the aircraft. In a 2018 mishap, a woman was killed in the resulting explosive decompression, becoming the only airline fatality for that year. The AD applies to all aircraft in the 600 to 900 series. There are also thousands of 737NGs in service in the rest of the world, and aviation authorities in other countries will likely also require the modifications.
The required changes will apparently vary depending on the aircraft model but include new stronger inlet spacers, a fan cowl support beam and a redesigned exhaust nozzle. The retrofits are expected to cost $7,650 per engine and the work will take about 90 hours. The comment period on the AD ends on Jan. 26 and all aircraft have to be in compliance by July 31, 2028.
