Inflight Wi-Fi hits more turbulence

(Image: Mark Horn/The Image Bank/Getty)
Inflight Wi-Fi and cellphone services - which transmit low power microwave radio signals within an aircraft's fuselage - have already been criticised by security engineers for providing a ready means for terrorists to remotely detonate explosives. Now the technology has been found to be interfering with flight critical electronics too.
This latest finding was made by Boeing while testing inflight Wi-Fi equipment for use on its next generation 737 twin-engined aircraft. The Seattle-based plane maker found that a certain type of new, brighter cockpit display made by Honeywell of Torrance, California, could go blank when an inflight wireless system, made by Aircell of Itasca, Illinois, was used nearby.
"Blanking of the display units was reported during electromagnetic interference certification testing of wireless broadband systems (Wi-Fi) on various 737NG airplanes," Boeing said in a statement issued today.
The firm adds it has not delivered any aircraft using the technology and will not activate any passenger Wi-Fi systems in future planes across its whole range of aircraft until Honeywell has made its new displays Wi-Fi proof.
In 2000, the British Civil Aviation Authority borrowed a couple of airliners - a Boeing 737 from British Airways and a 747 from Virgin Atlantic - and generated simulated GSM cellphone signals in them. As New Scientist reported, they found that avionics equipment in the cockpit were susceptible to high levels of interference - the first "scientific proof" there was an issue, said the CAA.
Commercial pressures to allow lucrative wireless services on board, however, led to the development of electromagnetic shielding standards for avionics equipment, designed to ensure that emerging portable electronic devices like smartphones and laptops using 3G and Wi-Fi connectivity did not cause problems.
It was while testing to the US Federal Aviation Administration's relevant standard that Boeing found the Aircell system interfering with the new "phase three" Honeywell multifunction cockpit displays, which are brighter then their predecessors.
The interference happened at Wi-Fi signal levels that are higher than is normally emitted by phones and laptops, Boeing says, but it is quite possible for consumer equipment not to perform to specification and kick out too much power - so no chances could be taken.
"We have identified a fix and are working to ensure that temporary blanking does not occur when displays are exposed to elevated levels of electrical energy," a Honeywell spokesman told New Scientist.
Whatever the issue here, it has to be sorted fast. There should be no way that technology as trivial as an inflight entertainment system should threaten flight safety. The industry has already learned this lesson the hard way: a fire in passenger video wiring caused the crash of Swissair 111 off Nova Scotia, Canada, in September 1998, killing 229 people.
The FAA is on the case. "We are aware of some issues involving interference between Honeywell flight displays and in-flight Wi-Fi that surfaced during certification testing," says Les Dorr, FAA spokesman. "We are currently working with both manufacturers to examine the technical data and test results. After a thorough review,we will consider if further safety action is necessary."