The world’s Dreamliners are currently grounded while regulators and the manufacturer aim to sort out problems with the plane’s batteries – which supply a heavy duty electrical system that replace the more traditional (and heavier) hydraulic controls in other planes.
I imagine, and hope, that the battery problems can be sorted out – though the Lithium Ion system chosen is notorious for overheating and fire risk – or “unexpected rapid oxidisation” as an earlier (non-aviation) LiOn battery fire problem was called.
But what worries me about the planes is a different issue – their outer shell is made of plastic, again considerably lighter than traditional aircraft materials, but lacking the quality of a Faraday Cage.
The Faraday Cage effect is what makes traditional airliners (and motor cars) safe from lightning strikes – lightening represents a terrific concentration of energy but, actually, very little charge – and so when lightning strikes a sheet of metal, like a car or an airliner, the charge is spread and the strike rendered safe (in contrast poor conductors like human flesh burn up, which is what makes us so vulnerable).
Now, the Dreamliner has a metal substructure which is designed to replicate the effect of a Faraday Cage but, having read a critical piece on this in the current edition of the New Scientist, I am not convinced it has been tested enough to be reliable. Anyone who has flown through the heart of an electrical storm – as I did a few years ago coming out of Tbilisi – will understand just how essential it is that the Dreamliner’s electrical properties are fully reliable.
Update: I am a hopeless speller and, as was pointed out to me I mis-spelled ‘lightning’ throughout this the first time round. Apologies.
- IAG boss says Dreamliner problems will be fixed, could be months (uk.reuters.com)
- Boeing notifies European airlines of Dreamliner delays (Reuters) (newsdaily.com)
- Investigation reveals cause of battery fire on Boeing 787 Dreamliner (arstechnica.com)
- 787 Dreamliner test flight under way (blogs.seattletimes.com)
- Boeing Delays Dreamliner Deliveries As Battery Problems Get Worse (forbes.com)