There IS redundancy built in Boeings. On a B727, it's called Manual
Reversion. There's also a Standby Hydraulic system for the Lower Rudder
wrote in message ...
When I read about Japan Airlines Flight 123 (Boeing 747-SR46) that crashed
due
a bad repair of the rear pressure bulkhead. And the subsequent rupture of
ALL
hydralic pipes. It makes me wonder WHY are airplanes designed with this
single-point-of-failure?

Seems a lot of crashs could been avoided if the hydralics system would
been
intact.
So why not design some kind of redudancy into the hydralics system?, just
seperating the hydralic pipe route could improve safety by minimising the
chance of all hydralics failing.
Or even have a electrical servo backup system should hydralics fail?

Bad repair - Hydralics ripped
http://en.wikipedia.org/wiki/Japan_Airlines_Flight_123
Cargo door - Hydralics ripped
http://en.wikipedia.org/wiki/America...ines_Flight_96
Engine rupture - Hydralics ripped
http://en.wikipedia.org/wiki/America...nes_Flight_191
Turkish DC-10 crashed at Orly due to total loss of hydraulic power
http://findarticles.com/p/articles/m...15/ai_70429487