5G & aviation: FAA's new AD applies to over 8,000 Boeing 737 aircraft worldwide
The administration said it was issuing the AD to address potential 5G interference during landing.
The AD affects approximately 2,442 airplanes in the United States and 8,342 worldwide.
According to the FAA, the new AD applies to all The Boeing Company Model 737-100, -200, -200C, -300, -400, -500, -600, -700, -700C, -800, -900, and -900ER series aircraft. The only exceptions are for models 737-200 and -200C series airplanes which are equipped with a certain flight control system.
The AD, however, is not applicable to landings at airports where the FAA determined the aircraft radio altimeters are safe and reliable in the 5G C-band environment. It also does not apply to airports where 5G isn't deployed.
The Need for the AD
The need for the FAA to issue the AD was because many systems on the Boeing 737 aircraft rely on the radio altimeter, including autothrottle, ground proximity warning, thrust reversers and Traffic Collision Avoidance System.
Radio altimeters cannot be relied upon to perform their intended function if they experience interference from wireless broadband operations in the 3.7-3.98 GHz frequency band (5G C-Band).
The FAA also recently determined that, during the approach, landings, and go-arounds, certain airplane systems may not properly function because of this interference. In turn, this could lead to increased flight crew workload while on approach with the flight director, autothrottle, or autopilot engaged. This would ultimately reduce the ability of the flight crew to maintain safe flight and landing of the airplane.
This AD requires revising the limitations and operating procedures sections of the existing airplane flight manual (AFM) to incorporate specific operating procedures for instrument landing system (ILS) approaches, among other measures, when in the presence of 5G C-Band interference.
The administration said it was issuing the AD to address the unsafe condition on these products. "The AD mandates procedures for operators to incorporate specific operating procedures for landing distance calculations, ILS (and GLS if installed) approaches, speed-brake deployment, go-arounds, and missed approaches, when in the presence of 5G C-Band interference as identified by Notice to Air Missions (NOTAMs)."
As mandated by the AD, "The operating procedures require the flight crew to execute a go-around if they encounter certain conditions during ILS approaches and prohibit them from using certain affected systems during the go-around until reaching a safe altitude."
Other Boeing Aircraft Affected
The new directive follows up on a similar AD the FAA had issued on February 14, which also applied to Boeing aircraft in the series 757 and 767. The AD revised the landing requirements for Boeing due to potential 5G interference during landing and affected around 1,138 airplanes in the U.S. and 1,984 across the world.