The US FAA wants Boeing 737 operators based in the US to install new circuit breakers, relays, wiring and switches in the cabin to give flight crews the ability to remove electrical power from errant in-flight entertainment (IFE) systems.

The proposed airworthiness directive (AD), issued on November 8, is based on an FAA analysis of 180 IFE systems on various aircraft, efforts originally spawned by the September 1998 crash of Swissair flight 111, an MD-11, off the coast of Nova Scotia.

Canadian safety officials ruled that the crash was instigated by electrical arcing from an IFE system.

"The review results indicated that unsafe conditions exist on some IFE systems installed on various transport category aircraft," the FAA concludes, pointing specifically to IFE systems it found that cannot be de-energized without removing power from systems needed for flight and landing, those that require the crew to pull circuit breakers to remove power, or crew procedures that have "not been properly revised" after installation of an IFE.

In particular, the FAA found that "certain" Boeing 737 models must be modified to include a switch in the flight compartment that will allow flight crews to turn off power to IFE systems and other non-essential electrical systems "in the event of smoke or fumes." Boeing issued service bulletins in 2004 and 2007 aimed at addressing the problems.

The agency says 1,176 aircraft in the US registry could be affected by the rule, with proposed upgrades costing in about US$15 million. Comments on the proposed rule are due by December 24.

Boeing could not be immediately reached for comment regarding how many aircraft have already been modified though service bulletins.