ANG C-130 down, 9 killed.

[dodgy-alan 1,587]

Thoughts go out to all those who have lost loved ones and colleagues, 

https://www.cbsnews.com/news/savannah-plane-crash-today-2018-05-02-live-updates/

[allardjd 1,853]

One suspects technical issues, since it was a very old airframe, literally on its way to Davis-Monthan to be retired.

 

RIP to the crew, peace to the families.  It appears to be nearly miraculous no one on the ground was hurt or killed.

 

John

[dodgy-alan 1,587]

Given the age of that aircraft you'd have thought that A, it would have been thoroughly checked before take off and B, been flown with flight crew only in case of something like this happening.  I can imagine a lot of questions will need to be answered.  In hindsight it might have been better to scrap her on site. I guess we'll find out eventually.

 

 

[allardjd 1,853]

There are some economic reasons for retiring US military aircraft to Davis Monthan and it's the general way things are done.  Most importantly, it's a source of parts to keep others going but also serves as a repository for aircraft that COULD be re-activated if needed in an emergency.  The environmental issues associated with scrapping large, complex military aircraft (e.g fluids, asbestos, mercury, lead) make it a difficult thing to do responsibly at sites that are not set up to deal with those things.

 

Can't disagree with the idea of flight crew only for a final flight - one suspects a boondoggle ride for some, but maybe not.  Military aircraft going to-from anywhere often carry service members on a space available basis for convenience and economic reasons.  If the aircraft were considered so decrepit that the flight was considered abnormally risky, I suspect that they would not have made it without taking special precautions or performing necessary repairs first.

 

Not sure what kind of budget the Puerto Rico ANG operates under either.  If they're like the rest of the PR government organizations, they can hardly afford to pay attention.  Don't know if that was a factor not, but can't rule it out.

 

John

[J G 927]

Thanks to social media the public get to see allsorts of aircraft crashes these days.  Followers of these forums have no doubt seen many posted here like this one.

 

My heart goes out to the friends and relations of the deceased, it must be twice as traumatic having to watch the moment of their demise on the news.  Such is the price of Facebook and the like. 

 

Watching the video, it would seem that there must have been something major that broke to cause the aircraft to behave in the way it did. It seemed to roll almost onto its back before very rapidly going exactly vertical before it hit the ground. I have seen footage of WW2 bombers with a wing off that went down less violently than that.

 

Also, there was a long pause between the crash noise and the explosion. You would expect a large bang as it probably had a lot of fuel on board, having just taken off, but this would be at the time of impact and not a couple of seconds later. It just seemed a bit strange, was their a volatile cargo perhaps, or maybe the angle it hit the ground played a part. 

[allardjd 1,853]

There's some pretty good analysis/speculation at PPRUNE on this.  Older C-130s, before the current FADEC systems, had cables from throttle levers to engines, necessarily using a very convoluted routing.  Earliest ones used 7 X 7 carbon steel cables.  Later ones went to 7 X 19 stainless steel.  Don't know if the cable upgrade was mandatory or if some of the older cables might still exist in older airframes.

 

There's apparently a well known phenomenon that a broken throttle cable puts the prop into reverse pitch - at the engine, the broken cable just seems to be a command to go to beta range, so it does.  That is not inhibited in flight, though to command it deliberately involves lifting the lever over a stop to pull it back into ground range. 

 

They say that several fatal C-130 take-off crashes have resulted over the years from broken throttle cables.   The speculation at PPRUNE indicates that the crash profile from takeoff to impact, including going fully inverted then nose-down,  is consistent with this happening, but doesn't constitute a smoking gun - other things could have caused it too.

 

Apparently, there are two in-flight engine shut-down procedures, one for "normal" circumstances, and one to be used if a broken throttle cable is suspected, which consists of pulling the T-handle (engine fire shutdown lever, I think).  I believe that moving the affected throttle lever if a broken cable is suspected can cause the loose cable to interact with other nearby things.  

 

The nine aboard were all service personnel, including some maintainers who were travelling with the aircraft.  Some kind of maintenance was performed while the AC was in Savannah but there are no details given of what that may have been.

 

That's about 110% of what I understand about this.

 

John