Honeywell Rescu406AFN

Boeing has said that they have asked "specific operators" of the 717, 737NG, 747-400, 767, and 777 to inspect as many Honeywell Rescu406AFN Emergency Locator Transmitters as they can, and report the results to Boeing and the FAA. They are attempting to collect data to assist the FAA in determining if another Airworthiness Bulletin needs to be issued on the ELT.

The ELT is currently the main suspect in the fire of an Ethiopian Airlines 787 Dreamliner at London's Heathrow Airport. The fire occurred approximately 8 hours after the flight landed, while it was sitting empty (approximately 4 hours before departure). It caused significant damage to the area around the ELT device, one of which is located just ahead of the vertical fin, and during the AAIB investigation damaged wiring to the device was found. It's believed that the wiring was damaged during assembly, and not by anything on the aircraft.

Both United and All Nippon Airways have inspected their Dreamliners, and both have reported at least one unit with damaged wiring. The units have been returned to Honeywell for investigation. The FAA issued an Airworthiness Directive ordering the inspection, but it only applies to the six aircraft flown by United, which is the only operator of the Dreamliner in the United States.

Over 1200 units have been installed on Boeing aircraft, and as many as 6000 are in use worldwide. This is the first known event involving the unit, but one reason it's scary is that there is no way to fight the fire in that area of the fuselage, if it were to happen in flight. The AAIB recommended either disabling the units until they could be inspected, or removing them altogether. Honeywell concurred with the recommendation, and the FAA ordered the inspections.

Boeing has asked airlines around the world to inspect Honeywell emergency locator transmitters (ELTs) fitted on over 1,000 aircraft ahead of possible action by airworthiness authorities to address a potential fire risk in the beacons.

Boeing says that it is asking "specific operators" of Boeing 717s, 737NGs, 747-400s, 767s and 777s to inspect aircraft fitted with Honeywell ELTs and gather data to support potential regulatory action by the US Federal Aviation Administration (FAA).

"Up to 1,200 aircraft have been fitted with the devices, but we are asking that airlines inspect as many as possible and report back within 10 days to help regulators decide what, if any, action to take," says a Boeing spokesman.

Boeing's request comes after an AAIB special bulletin that was issued in relation to its investigation into the fire on board an Ethiopian Airlines 787-8 that was parked at London Heathrow on 12 July.

www.flightglobal.com...

I think an easy fix would be to simply move the ELT closer to the aircrew.

2nd

reply to post by iamhobo


There are multiple units on the plane. One reason they put it on the aft fuselage is because so many times that section of the plane survives, which means the odds are that the ELT will survive as well, and be able to transmit.

On the KC-135, it's an ejectable transmitter at the base of the tail. There are two shock sensors, one near the nose, and one in the main wheel well. If they shatter, then the panel holding the ELT in releases, and it ejects the unit out, and it begins transmitting (at least that's how they used to do it).

One of the things I find interesting about this is that there are so many units out there, but there hadn't been an incident caused by one until the Dreamliner fire, and now we have at least three units on Dreamliners damaged, possibly prior to installation. Did Honeywell change their QA? Or is someone messing with them?