AD 2020-16-51 Requires Inspections Of The Engine Bleed Air 5th Stage Check Valve On Each Engine

The FAA is adopting a new airworthiness directive (AD) for all The Boeing Company Model 737-300, -400, -500, -600, -700, -700C, -800, -900, and -900ER series airplanes. An emergency AD was sent to all known U.S. owners and operators of these airplanes.

This AD requires inspections of the engine bleed air 5th stage check valve on each engine, and replacement of the engine bleed air 5th stage check valve if any inspection is not passed. This AD was prompted by four recent reports of single-engine shutdowns due to engine bleed air 5th stage check valves being stuck open. The FAA is issuing this AD to address the unsafe condition on these products. This AD is effective August 26, 2020 to all persons except those persons to whom it was made immediately effective by Emergency AD 2020-16-51, issued on July 23, 2020, which contained the requirements of this amendment. The FAA must receive comments on this AD by September 25, 2020.

Supplementary Information: On July 23, 2020, the FAA issued Emergency AD 2020-16-51, which applies to all The Boeing Company Model 737-300, -400, -500, -600, -700, -700C, -800, -900, and -900ER series airplanes, AD 2020-16-51 requires inspections of the engine bleed air 5th stage check valve on each engine, and replacement of the engine bleed air 5th stage check valve if any inspection is not passed. This emergency AD was sent to all known U.S. owners and operators of these airplanes. This action was prompted by four recent reports of single-engine shutdowns caused by engine bleed air 5th stage check valves stuck in the open position. 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 offairport landing.

FMI: www.regulations.gov