US aviation regulators have cleared several Airbus and Boeing models to operate low-visibility landings at airports where ‘5G’ communications services will become available.
The US FAA’s work means some 45% of the US commercial fleet has been approved for the operations.
Its analysis follows concerns over potential interference from 5G communications services accessing frequency spectrum shared with critical aircraft systems.
Eighty-eight airports likely to affected by 5G interference would have been off-limits to low-visibility landings.
But wireless companies have agreed to establish buffer zones around airports with nearby 5G transmitters, for six months, and hold back deployment until 19 January to give the FAA time to assess data.
Two radio-altimeter products which are fitted to a “wide variety” of Airbus and Boeing jets have been since been cleared, says the regulator.
Among the aircraft types approved are the Airbus A320 family, the A330 and A350, as well as the A310, plus the Boeing 737, 747, 757, 767, MD-10 and MD-11.
This clearance, says the FAA, will enable 48 of the 88 affected airports to offer their runways. “[We] expect to issue more approvals in the coming days,” it adds.
But the FAA adds that flights at some airports “may still be affected”. It says it is working to understand how radar-altimeter data is used by other flight-control systems in aircraft.
Boeing 787 operators, it states, will need to take “additional precautions” when landing on wet runways at affected airports.
The FAA says anomalies on all three 787 variants – which could affect the flight director, autothrottle, thrust-reversers, configuration warning system, or collision-avoidance systems – “may not be evident” until the aircraft is at low altitude on approach.
If interference prevents transition from ‘air’ to ‘ground’ mode on the type, such systems as speedbrake and reverse-thrust could malfunction and leave braking as the only option to decelerate.
“The presence of [5G] interference can result in degraded deceleration performance, increased landing distance, and runway excursion,” the FAA warns.
It adds that it is analysing data for other Boeing aircraft types to establish whether they might be similarly affected.
“Passengers should check with their airlines if [adverse] weather is forecast at a destination where 5G interference is possible,” the regulator advises.