Boeing Boeing gone

[ed731pdh]

Getting interesting now, self destructing emergency transponders on 787s. Whatever next? I hear rumours that Boeing's situation dates back to their acquisition of McDonnell Douglas, McDD would always farm out for parts to 3rd parties and Boeing took on that mantra, dumping their in house policy in the process.

Meanwhile, in the lounge sit's Mrs H (who worked with EADS designing the A380), quietly sniggering at Boeings woes.

[Refugee]

I started a thread on the batteries when they went bang.
You will have to register to see it though.
http://www.forum.radios-tv.co.uk/viewtopic.php?f=17&t=3954

[camallison]

Most emergency transponders are made by a division of Honeywell, so there's chance that the A380 has the same or similar model. One report I read pointed to the use of particularly brittle Teflon coating on the loom wiring to the transponder and other equipment. Should the insulation crack and/or fall off, any equipment once shorted could give similar problems.

Colin

[Refugee]

I thought that the transponder had another lithium battery in it that keeps it going after all other power is lost.
Perhaps it is lithium batteries exploding yet again.
The main batteries will have gone with a spectacular bang looking at the photos.
Even the steel case is buckled.

http://www.technologyreview.com/news/509...erheating/

[ed731pdh]

Apparently this model transponder is specifically designed to interface into the 787 avionics systems, I guess it's a case of 3/4s standard squalker kit and 1/4 interface. One does wonder if the design specified for the 787 was designed around lithium cells as part of the weight reduction process rather than the standard stuff fitted to other planes.

A telling point, the A350 from EADS is designed to use standard cells and EADS have been quoted to have said we have no plans to use lithium cell technology due to it's newness and questionability.

[camallison]

I have followed the development and deployment of lithium batteries with interest over the years. Does anyone remember the fire aboard the MIR space station when Foale, the Brit, had to evacuate to a Soyuz escape capsule with the other crew. That was a lithium module fire and the flame was apparently 6 feet long! Not nice when there is a vacuum on the other side of the module wall it is playing against.

In the European Spacelab programme, lithium was a banned substance in any equipment deployed, including lithium (Tadiran) standby batteries in systems with volatile memory. The company I was working with at the time had a contract to supply a piece of control equipment to the German scientific module. In its normal form, our equipment had Tadiran batteries to support the volatile memory - taken off for flight and replaced by a battery with another chemistry.

In 2001, I visited the Mitsushima works of Mitsubishi Chemicals and also their Yokohama laboratories. The visit was to look at progress with their development of lithium ion battery chemistry. As you well know, these batteries don't like overcharging or short-circuit discharging and are prone to catching fire. We performed some testing in fire-proof cells built out of furnace bricks with fire-proof glass windows let into the sides.

The tests involved overcharging one of their batteries and, in the cell next door, overcharging a competitor's battery (Sony). The Mitsubishi battery swelled to about 30% bigger than normal. The Sony battery suddenly spouted a flame around 6 feet long and 2 feet wide at its widest. That battery was the one being fitted at that time to Sony-Ericsson mobile phones as standard.

Shortly afterwards, the Sony-Ericsson battery was subject to recall and all were replaced.

The chemistry of lithium ion batteries is such that this can happen whatever protection they put in and the only solution is to guard against it. I did some calculations at the time and reckoned that lithium ion batteries have a higher potential energy density (explosive power) than Semtex!

My own personal feeling is Boeing have gone one step too far in putting these batteries in aircraft as there will always be this inherent problem.

Colin

[Andy M0FYA]

The chemistry of lithium ion batteries is such that this can happen whatever protection they put in and the only solution is to guard against it. I did some calculations at the time and reckoned that lithium ion batteries have a higher potential energy density (explosive power) than Semtex!

Colin

Having just bought a Ryobi screwdriver/drill with a Lithium Ion battery, I'm getting worried!

Should I store it in the garden under a bucket rather than in the house?

Andy

[Refugee]

Just go onto U-tube and search for exploding lithium battery.
There are plenty of people whom have tested them to destruction.
There is even a training film for airline crews showing how to deal with laptops that are in hand baggage when they blow up.