WiFi is moving from coffee shop hot zones to business jet cabins as the FAA continues to work with airframe OEMs and maintenance, repair and overhaul shops to establish formal guidelines for certifying the onboard WiFi equipment and enabling inflight use of passenger-carried wireless devices.

“Transmitting portable electronic devices are not FAA certified,” says Ric Peri, VP government and industry affairs for the Aircraft Electronics Association. “The FAA’s concern is that those devices interfacing with the WiFi infrastructure could adversely impact the communication, navigation, or other existing electronics required for safety of flight.”

“WiFi” is a trademark of the Wi-Fi Alliance, a 300-member global industry group promoting the growth of wireless local area networks. Today, WiFi is a synonym for the IEEE 802.11 technology, the standard to which wireless products, such as smart phones and modem-equipped laptops, are certified.

“Probably 85-90% of our quote requests are for [onboard] high-speed data systems with WiFi access,” says David Loso, manager of avionics sales for Midcoast Aviation. “The FAA sees WiFi as a ‘new and novel’ technology, but it’s really no longer new, novel or unique.”

The current approval route for onboard WiFi equipment on U.S. registered aircraft is through an “issue paper,” which the FAA calls “the clear pathway through which the agency addresses new technology.” For an MRO seeking a WiFi installation supplemental type certificate, the issue paper spells out the testing procedure that the installer must follow to assure that the WiFi equipment—the router, transceivers, associated wiring and external antenna—will perform its intended function and shield the aircraft’s electronics from any interference from a portable electronic device.

Since the testing only applies to the technology being installed, it does not qualify the aircraft as transmitting portable electronic device-tolerant. According to the FAA, the aircraft’s operating certificate holder is the only one who can make that determination, based on the testing done by a maintenance provider. Under AC91.21-B, RTCA DO-294 is considered an acceptable test method as the basis for that decision.

WiFi Testing Process

Gary Harpster, senior avionics sales representative for Duncan Aviation, explains that the issue paper mandates a multi-step testing process.

“The FAA is concerned about any type of device that uses 802.11, which is the standard WiFi communication protocol, using up to one watt of power output,” he says. “Once the WiFi equipment is installed, the technician places a rogue transmitter at each seat on the airplane, which simulates the interaction of a wireless device with the WiFi suite.”

The rogue transmitter runs at five times the normal output capacity of a laptop computer. “When you do that, you are testing at four to five watts of power, or four to five times what the FCC allows at a frequency of 802.11a, b or g,” says Harpster. “Most testing is in the 802.11b range.”