Is in-flight WiFi messing with cockpit displays? The FAA thinks so.

The FAA has ordered the replacement of various cockpit displays on more than 1,300 Boeing aircraft according to this article in the Wall Street Journal.

In extreme cases, Wi-Fi devices in the cockpits of certain commercial jets can cause cockpit displays to flicker or temporarily blank out. FAA tests on the ground resulted in one outage lasting about six minutes.

Over the next several years, airlines will be required to replace the displays in Boeing 777 and 737 aircraft in a precautionary measure to prevent issues like the one described above.

The article did note that no inflight screen blackouts have actually occurred, but that the FAA was insistent that it could occur based on tests performed on the ground.

Since the article is via subscription only, I’ve copied it below for your convenience:

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Federal regulators have ordered replacement of pilot displays on more than 1,300 Boeing Co. BA -1.08% jets, including some of the newest 737 models, to prevent possible interference from Wi-Fi devices used in cockpits.

Federal regulators have ordered replacement of pilot displays on more than 1,300 Boeing jets. U.S. airlines will have five years to swap out the displays on Boeing 777 and 737 models. Pictured, a pilot in the cockpit of a Boeing 777 in 2011. Getty Images
The Federal Aviation Administration’s safety directive, released Tuesday, aims to ensure that essential information such as airspeed, altitude and heading doesn’t temporarily disappear from certain instrument displays manufactured by Honeywell International Inc.

The affected displays are susceptible to interference from Wi-Fi devices intended for routine use by many pilots during flights, according to the FAA document. But the agency said the displays also are vulnerable to radio frequency transmissions from satellite-communications systems, cellphones and other signals.

The latest FAA move highlighting such potential dangers comes as passenger use of portable electronic devices—from tablets to laptops to cellphones—is expanding. Meanwhile, U.S. airlines increasingly are outfitting pilots with company-issued devices to help them do their job.

U.S. airlines will have five years to swap out the displays on Boeing 777 and 737 models, which can cost thousands of dollars apiece. Each aircraft has multiple screens. Supported by updated data collected by the FAA, the final directive applies to nearly 10 times the number of planes covered under the agency’s proposal last fall.Foreign carriers and regulators are expected to embrace the U.S. requirements.

Despite requests from Honeywell and various carriers to reduce or delay the impact of the final order, FAA officials said they concluded the action was necessary based on separate safety analyses conducted by the agency and Boeing.

In extreme cases, Wi-Fi devices in the cockpits of certain commercial jets can cause cockpit displays to flicker or temporarily blank out. FAA tests on the ground resulted in one outage lasting about six minutes.

Though industry groups argued the FAA was going too far because no display incidents have occurred in flight, the FAA said Boeing’s own tests determined that display “blanking was a safety issue.” If a screen went dark during takeoff or a landing approach, according to the FAA, the result could be “loss of control of the airplane.” Even relying on standby instruments could lead to planes flying into natural or man-made obstacles, according to the FAA, or pilots trying to regain control “at an altitude insufficient for recovery.”

The Chicago plane maker and Honeywell took voluntary action earlier to replace some of the units. Replacement screens have enhanced shielding and upgraded software, and those versions are now being installed on new jets in the factory. A Boeing spokesman said the FAA is ordering fixes the company recommended to airlines in 2012. On Tuesday, a Honeywell spokesman reiterated that “no display units have ever blinked in flight due to Wi-Fi interference.”

In the past, Honeywell called the testing issue an “isolated incident” involving frequencies and signals that it said were much stronger than typical Wi-Fi signals. In comments submitted to the FAA on the initial rule, Honeywell said the potential for interference fell “well within the FAA’s acceptable risk zone.”

As part of its comments, Southwest Airlines Co. told the FAA that more than 400 of its 737 jets have flown more than 2.3 million hours with Wi-Fi systems operating in the cabin. There wasn’t a single display incident related to Wi-Fi signals, according to the carrier’s submission, which Southwest said “indicates a negligible level of risk.”

As a makeshift step, the FAA initially ordered placards placed in the cockpits of some planes prohibiting use of Wi-Fi devices. The agency later gave Delta Air Lines Inc. a waiver to allow specially trained pilots to use such devices during trips carrying passengers.

But in the final rule, slated to be published Wednesday in the Federal Register, the FAA concluded that such interim safeguards were inadequate as “corrective action for the unsafe condition” identified by testing and formal risk analyses.