Hydralics vurnability by design.

[[email protected]]

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/American_Airlines_Flight_96
Engine rupture -> Hydralics ripped
http://en.wikipedia.org/wiki/American_Airlines_Flight_191
Turkish DC-10 crashed at Orly due to total loss of hydraulic power
http://findarticles.com/p/articles/mi_m0UBT/is_7_15/ai_70429487

[Bertie the Bunyip[_24_]]

wrote in :

> 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?
>

They aren't.


> 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?,

Hmmm. Maybe you should write to Boeing and Airbus about this..

I'm sure they'd appreciate this singel point of vurnability pointed out.

Maybe Ken can help you with this. I think he made a hydraulic system out of
ole toilet paper tubes at one time.


Bertie

[Mxsmanic]

writes:

> 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?

They aren't. That was an exceptional situation in which multiple hydraulic
systems passed through a single opening in the bulkhead, which was a design
oversight. The systems were indeed independent, but when the bulkhead was
fortuitously sheared away at precisely the point where the several systems
were in close proximity, it disabled them all.

> Or even have a electrical servo backup system should hydralics fail?

There are often multiple back-ups for all critical systems. The 747 is well
equipped with back-up systems.

In some cases, there isn't much choice. If you have multiple systems moving
the elevators, inevitably they all must come in close proximity where they
actually connect to the elevators, so if something happens there, you could
still lose them all.

[Bertie the Bunyip[_24_]]

Mxsmanic > wrote in
:

> writes:
>
>> 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?
>
> They aren't. That was an exceptional situation in which multiple
> hydraulic systems passed through a single opening in the bulkhead,
> which was a design oversight. The systems were indeed independent,
> but when the bulkhead was fortuitously sheared away at precisely the
> point where the several systems were in close proximity, it disabled
> them all.
>
>> Or even have a electrical servo backup system should hydralics fail?
>
> There are often multiple back-ups for all critical systems. The 747
> is well equipped with back-up systems.
>
> In some cases, there isn't much choice. If you have multiple systems
> moving the elevators, inevitably they all must come in close proximity
> where they actually connect to the elevators, so if something happens
> there, you could still lose them all.
>

Nope

Bertie

[Robert M. Gary]

On Feb 5, 6:22*am, wrote:
> 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?

You really should write to Boeing and Airbus about this discovery
you've made. You may save lives!! Please, please post their response
if they respond to you.

-Robert

[tom418]

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/American_Airlines_Flight_96
> Engine rupture -> Hydralics ripped
> http://en.wikipedia.org/wiki/American_Airlines_Flight_191
> Turkish DC-10 crashed at Orly due to total loss of hydraulic power
> http://findarticles.com/p/articles/mi_m0UBT/is_7_15/ai_70429487