PPRuNe Forums - View Single Post - 787 Batteries and Chargers - Part 1
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Old 19th Mar 2013, 14:20
  #1035 (permalink)  
Ian W
 
Join Date: Dec 2006
Location: Florida and wherever my laptop is
Posts: 1,341
CockneySteve
Quote:
Overall the more controlled certification level testing is far more efficient and complete in a ground test than in an unpredictable and limited air test. unquote

As demonstrated by a new model released to service,which has such major incendiary problems that the entire fleet is grounded?

Sure does inspire confidence.....NOT
Steve - a word in your shell-like...

You are conflating the scenarios used in the original testing with the capabilities and limitations of ground testing. The original test scenarios obviously did not cover the failures that have occurred, but included a lot of flight testing. This is a limitation of the scenario writers and approvers not of the ground or air testing. A full set of scenarios and test cases that requires extreme failures of systems can only be run successfully on the ground. The aircraft testing can only be of standard battery performance and this nominal testing is just as easy on the ground.

The one area I would test in a live aircraft is having airline first line maintenance and push crews do repeated 'turn around's and routine towing with one of the 'spare' 787s currently clogging Everett. If the FAA would allow it fly a 787 on multiple short rotations and ground turn arounds. While that was happening I would watch the ground crews and see what they really did as opposed to what they say they do and people expect them to do. I suspect that something in the ground handling is unexpected. Does the ground crew safety man ride the brakes running down the main battery when the aircraft is towed? Do they routinely leave nav lights on running down the battery(ies), do they open the electronics bay door and leave it open which on frosty nights could let batteries get too cold etc.

One thing that you can be sure of is that Boeing is very very aware that if one of these batteries causes even a minor problem in the next 5 years the 787 may go the way of the Comet which would be devastating for the company. So they have nothing to gain and everything to lose if these tests are skimped.

As it is, the 787 will be one of those aircraft that is repeatedly pilloried by 'the trade media' in the same way as the Harrier (until the Falklands) and the Osprey - until it went 'live' in action.

Last edited by Ian W; 19th Mar 2013 at 14:25.
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