Null references (oh no, not again!)

[Andrei Alexandrescu]

Sean Kelly wrote:
> Georg Wrede wrote:
>> Nick Sabalausky wrote:
>>> "Walter Bright" <newshound1 at digitalmars.com> wrote:
>>>> I started my career doing flight critical mechanical designs for 
>>>> Boeing airliners. I had it pounded into me that no matter how 
>>>> perfect you designed the parts, the next step is "assume it fails. 
>>>> Now what?" That is why Boeing airliners have incredible safety records.
>>
>> Yup. That's what McDonnell didn't do with the DC-10. They were 
>> crashing mysteriously in mid-fligt, and nobody survived to tell.
>>
>> The DC-10 had three entirely separate steering systems: a mechanical 
>> (as  in wires from cockpit to ailerons), a hydraulic one, and an 
>> electrical system.
>>
>> After a superior pilot(1) actually brought his plane home after 
>> disaster struck, it was found out that the reason to all the crashes 
>> was a cargo door lock, which could be shut carelessly and then, if the 
>> ground guy was strong enough, lock the latch by force, leaving it only 
>> partly locked. Once in the air, the airpressure blew the door open, 
>> resulting in the passenger floor collapsing, and shredding the 
>> steering systems.
> 
> At Newark Airport in New Jersey, the Air Control Tower's network is 
> linked to radar and such via redundant cables, as expected.  However, 
> these cables are run right next to one another, eliminating any benefit 
> that the redundancy might provide.  Funny how things change between the 
> design requirements and implementation.

That's why the bad guys took almost succeeded in that Die Hard movie 
taking place on an airport!

Andrei