Built in obsolescence and aircraft....

[PMC]

Or Airbus A340s.

[PMC]

The Titanic was safe, just those icebergs which were dangerous.  As for the Hindenburg, it's a tragic shame that more Nazi party officials didn't take up travelling in hydrogen filled airships.

[PMC]

Of course, back in the day there was no built in obsolescence.

Just check this out:
http://www.poynting.co.za/consulting/images/proj_dakota2.jpg

It's a DC 3 fitted with turboprop engines and updated avionics as used in South Africa.  The airframe is pretty much unchanged in 70 years and judging from the way the Dakotas seem to run and run they will be around for some considerable time yet.  It's successor, the Hercules first flew in the mid fifties yet is being updated to extend it's life even further.

The USAF don't plan on retiring the venerable B52 (first flew in November 1952) until 2050 at least, while the F4 Phantom (still on active duty with the Luftwaffe, Iranian and Spanish air forces) first flew in 1957/8.  Turkish and Italian F104 Starfighters first flew in 1952 and are still in service today...

... although technically the RAF still operates two Spitfires, a Hurricane and a Lancaster as part of the Battle of Britain memorial flight.  The combined ages of the Spitfire, Hurricane and Lancaster formation is 183 years!