Aircraft Wi-Fi fears won't fly

Testing reveals the potential for Wi-Fi interference with certain Honeywell displays in some Boeing 737NG aircraft. Which is a lot different from saying there's a real-world problem.

Rupert Goodwins
Rupert started off as a nerdy lad expecting to be an electronics engineer, but having tried it for a while discovered that journalism was more fun. He ended up on PC Magazine in the early '90s, before that evolved into ZDNet UK - and Rupert evolved with them into an online journalist.
Rupert Goodwins
2 min read

Boeing 737-900ER
Certification testing of Honeywell Phase 3 Display Units on Boeing 737NG aircraft revealed the potential for interference from Wi-Fi for those specific displays. Honeywell emphasizes that there have been "no blanking incidents of in-service aircraft with the Wi-Fi system installed," according to the publication Flight Global. Boeing

There's nothing the world likes more than a good radiation scare. Mobile phone health panics are quiet at the moment--which could be permanent, like the microwave oven cancer flap that went into spontaneous remission and stayed there. Instead, the burgeoning world of in-flight entertainment beckons as the next fear factory.

Take this story from the generally sensible Flight Global publication: "Wi-Fi interference with Honeywell avionics prompts Boeing action." Sounds quite scary, especially since it's a report on a problem uncovered during certification for Aircell's Gogo, an in-flight passenger Internet system. In-flight Internet is the next big thing: will it lead to fiery death?

No--well, not unless you're playing some online shoot-em-up. The report gives the lie to the headline: the problem was found during testing at "elevated power levels" and results in one particular variant of a cockpit display panel temporarily blanking out. It came back within an acceptable time period.

Which is how and why you do these tests. Like airframe and engine testing, you push parameters to well beyond operating limits to see if anything goes pop. What the tests have not shown is that there's any real-life problem. At normal power levels, there's no problem. Using any other variant of the display panel: no problem. The actual Wi-Fi system itself: no problem. Honeywell, which makes the over-sensitive display panel, is working on a fix (slap a cap on it, chaps) and meanwhile, Boeing has put the certification process on hold until everything's OK.

And the article is clear on this. It's just that the headline writers couldn't resist a bit of hyperbole. There are plenty of chances for stories about avionics being too sensitive to the aircraft's own two-way radios, or ground radar signals, or whatever. But nobody would write them, because outside the specialist engineering press they're not really stories at all.

Even within the RF design community, they only have currency as war stories--how we used an unusually well-trained sniffer herring to track that 2.5GHz spur down to an out-of-spec resistor. That sort of thing.

So, don't panic. Read the story, not just the headline. The worst that'll happen is you'll have to wait a little longer before you get to read your spam at 35,000 feet.

Read more posts by Rupert Goodwins at ZDNet UK's Mixed Signals.