chalk's mallard- failed spar?

[beaky]

I had first suspected a fuel/engine-related explosion as the cause of the wing separation, but this article indicates the wing may have failed first...  don't know much about internal inspections on these planes, but it seems either the cracks couldn't be detected during normal inspections, or some corners were cut along the line. Either way, tragedy aside, this is going to be a big problem for this tenacious little airline...

http://www.yorkdispatch.com/nationworld/ci_3330461 :-/

[Hagar]

Very interesting although I assume that this is only a theory at the moment. They keep going on about the age of the aircraft but I don't think that or metal fatigue would affect a conventional low performance aircraft like the Mallard. There are plenty of DC-3s still flying with no fatigue problems & I'm sure they will continue to do so for many years yet. I don't know how often these amphibians operate from water but the salt water environment & repeated strain of water landings/take-offs on the wing spars might affect this more than the age of the aircraft.

[beaky]

Oh sure, the media will go on and on about the age of the plane... typical.
 If there was cracking that was missed during inspections, there's no doubt that the marine environment and many water takeoffs and landings (often in pretty choppy water- there was actually a fatal crash of another Chalk's bird years ago, attributed to landing in rough conditions) was more of a factor than chronological age... we all know how long an aluminum aircraft can last if pampered and protected...

[KDSM]

What about overloading mistaken or on purpose ...could that cause cracking?

I dont know im just throwing out ideas and making no assumptions

[Hagar]

What about overloading mistaken or on purpose ...could that cause cracking?

I dont know im just throwing out ideas and making no assumptions

I think it's pointless to make wild guesses & it seems they have enough of the aircraft to do a proper & thorough investigation. These sort of cracks take a long time to develop & if this is the cause they would have been there for a very long time. The wing spars of a floatplane take a lot more punishment than on a conventional aircraft as they're contintually subjected to stress transmitted through the wingtip floats all the time they're on the water. Landing & taking off from rough water puts even more strain on them. This could easily result in metal fatigue over a period of time.

[Jakemaster]

I doubt it was any human error such as overloading.  It seems like the failed spar is actually the case:  Over time, the rough waters have battered it and Im sure that it was probably weakened by it and maybe even a little rusty.  

Its a sad tragedy, but after long term use of anything its most likely gonna break, its just unfortunate that it caused so many deaths