Comments on: Dreamliner 787 delays made official by Boeing http://blogs.crikey.com.au/planetalking/2013/02/09/dreamliner-787-delays-made-official-by-boeing/ Wed, 19 Jun 2013 14:54:56 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: Theoddkiwi http://blogs.crikey.com.au/planetalking/2013/02/09/dreamliner-787-delays-made-official-by-boeing/comment-page-1/#comment-15312 Theoddkiwi Mon, 11 Feb 2013 05:06:17 +0000 http://blogs.crikey.com.au/planetalking/?p=29169#comment-15312 Hi My first post here, I feel the need to make a technical point of difference. Aircraft batteries have two main functions. One is to provide a means of power on the ground for initial power until an alternative is supplied eg ground power, and start the APU which will then take over supply of power. The second and probably most important function is to provide back up power should engine generated power be lost. In the case of the 787 like most aircraft eg 767, A320 and A330 the batteries provide power to the instruments and to start the APU. They are NOT used to operate major systems such as hydraulics, flight controls or air conditioning. That function is provided by the Ram Air Turbine (RAT) which would automatically deploy should engine generated power be lost. RATs generally have an electrical generator and possibly a hydraulic pump. The RAT generated electricity would power the more power heave flight controls, hydraulics etc and even that would be until the APU is started. The concern with the 787 batteries should not so much be with the loss of availability of the battery but more so the potential fire. Replacing the batteries with a different type will be the simplest and easiest long term fix. Hi My first post here, I feel the need to make a technical point of difference. Aircraft batteries have two main functions. One is to provide a means of power on the ground for initial power until an alternative is supplied eg ground power, and start the APU which will then take over supply of power. The second and probably most important function is to provide back up power should engine generated power be lost. In the case of the 787 like most aircraft eg 767, A320 and A330 the batteries provide power to the instruments and to start the APU. They are NOT used to operate major systems such as hydraulics, flight controls or air conditioning. That function is provided by the Ram Air Turbine (RAT) which would automatically deploy should engine generated power be lost. RATs generally have an electrical generator and possibly a hydraulic pump. The RAT generated electricity would power the more power heave flight controls, hydraulics etc and even that would be until the APU is started. The concern with the 787 batteries should not so much be with the loss of availability of the battery but more so the potential fire. Replacing the batteries with a different type will be the simplest and easiest long term fix.

]]> By: comet http://blogs.crikey.com.au/planetalking/2013/02/09/dreamliner-787-delays-made-official-by-boeing/comment-page-1/#comment-15295 comet Sat, 09 Feb 2013 22:36:31 +0000 http://blogs.crikey.com.au/planetalking/?p=29169#comment-15295 As I write this post, BOE05 is making its final approach into Everett. It should touch down in few minutes. As I write this post, BOE05 is making its final approach into Everett. It should touch down in few minutes.

]]> By: comet http://blogs.crikey.com.au/planetalking/2013/02/09/dreamliner-787-delays-made-official-by-boeing/comment-page-1/#comment-15293 comet Fri, 08 Feb 2013 22:13:34 +0000 http://blogs.crikey.com.au/planetalking/?p=29169#comment-15293 Airbus will almost certainly switch to Nickel Cadmium batteries, to avoid uncertainty. Maybe it'll add about 100kg of weight to the A350, but that's better than a delay. The Cadmium is highly poisonous for the environment, but NiCADs are more suitable for high discharge applications than Nickel Metal Hydride (NiMH). Meanwhile, the only thing that Boeing has been able to successfully prove is that everything it says turns out to be false, and that it can't be trusted. Airbus will almost certainly switch to Nickel Cadmium batteries, to avoid uncertainty. Maybe it’ll add about 100kg of weight to the A350, but that’s better than a delay.

The Cadmium is highly poisonous for the environment, but NiCADs are more suitable for high discharge applications than Nickel Metal Hydride (NiMH).

Meanwhile, the only thing that Boeing has been able to successfully prove is that everything it says turns out to be false, and that it can’t be trusted.

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