posted on Jan, 17 2013 @ 11:16 AM
Originally posted by Harlequin
in the event of total failure (thats everything including all back-ups) - with NO mechanical back up anyway , all these FBW aircraft will just fall
out of the sky , and if the engine and apu fail , then the ram air turbine is deployed -and boeing has to show that (and batteries) can power it.
I'm sorry, but your post is ridiculous on several levels.
Firstly, all FBW aircraft currently in operation, or on the drawing boards, have mechanical backups to the flight controls - you can physically remove
the flight computers from the aircraft and you would still have pitch, yaw and roll command authority on the aircraft.
Secondly, in the event of a dual engine failure, and the inability to start the APU, a Boeing 787 and an Airbus A330 (a plane that is now 20 years
old) are in the same boat - minimal systems available based off the power available. You don't lose anything more in a Boeing 787 in that case than
you do in the Airbus.
Thirdly, from the article Boeing must show the 787 is capable of safe flight with the engine and APUs inoperative. Alternate sources of power may
include the battery, ram air turbine or a permanent magnet generating system.
- isn't a special consideration above and beyond that which exists
in the standard consideration of both the FAA and the EASA for any LCA that undergoes certification. The A380 was required to show the same thing
during its certification.