PC-12 Down In Florida

[GarageYears]

Not good:

Story on CNN here: Kansas family dies in Florida plane crash - CNN.com

But would anyone care to comment or have further details on the following from the story:

Firefighters and police lifted the plane to make sure the sixth victim wasn't underneath, Judd said, adding the child may have fallen through a hole in the plane before the crash.

According to the report debris was spread over 4 miles...

I fail to see how either the possibility of a 'hole' in the plane or a 4-mile debris trail can be the result of anything other than a mid-air collision? But no mention of this so far....

[fantom]

There are several other possibilities.
How about in-flight break-up? Overspeed maybe?

[GarageYears]

There is a pic in the CNN story that shows the crashed aircraft largely intact, though I'll grant the tail appears missing. Not sure about the right wing either now I looked again.

[TampaSLF]

Pics of site at this link Polk County plane crash 06-07-12 | TBO.com

Miami control was quoted on our local news as them being about 25 minutes out of clearing Customs at Ft Pierce approx 21,500 ft when a hard turn, followed by another hard turn and Mayday without details of the specific problem.
Lost from radar and no further comms.
A lot of effort is going into finding the lost 13yo boy who was verified on plane leaving Ft Pierce but not found at crash site.

Such a sad story. May the answers be found soon. Wx was rainy over whole state with embedded squalls, but not as strong as our "normal" summer thunder boomers.
CNN characterizes the area as swamp; actually it is upland scrub, so search and investigation won't be as difficult.

[Huck]

Huge storms in the area - and an almost 90 degree course change before the incident.

[GroundProxGuy]

Not exactly pertinent to the accident investigation, but interesting to me:

Casey Anthony: Casey Anthony rode on plane that later crashed, killing family of 6 - Orlando Sentinel

[BobnSpike]

I can think of about two dozen reasons why an airplane might break up in flight. Assuming, of course, that in the absence of anything other than reports from notoriously ignorant and inaccurate news reporting agencies that an inflight breakup actually occurred.

I will give more credence to a midair being the only possible explanation when the other aircraft involved, or its wreckage, turns up.

[Lonewolf_50]

http://www.pprune.org/private-flying...n-pc-12-a.html

Gents:

I began a thread this morning on the crash, in the forum for private flying, as that is where I suspected such a thread belongs.

My question remains, based upon a service ceiling of 30k, the report being that the plane appeared to run into trouble at 26k, and my assumption (possibly in error) is that the aircraft has a pressurized cabin type:

Would a loss if pressurization lead to quick incapacitation of the pilot and perhaps a spiral / dive/ death spiral, with break up happening well into the dive due to speed being exceeded?

That's where my brain went first, as I have no sense of what autopilot features this aircraft typically carries.

Now that I see what you all are seeing, perhaps flying into bad weather is a more Occam's Razor explanation.

Sad story.

[ATPMBA]

From the pictures of the wreck I thought it would be a survivable crash.

From my memory this is the 4th crash in the USA of this type aircraft in the last few years. Perhaps it is too much aircraft for the pilots who air getting into trouble.

[kenhughes]

I don't know how accurate the flight tracking records on FlightAware.com are, but it seems that the aircraft made a sudden 90deg turn to starboard at 12:33 and dropped below its stall speed at 12:35, but maintained FL260:

FlightAware > Flight Track Log > N950KA > 07-Jun-2012 > KFPR-3JC

It then returned to 255kts for three minutes before starting a descent.

[Lonewolf_50]

Ken, possible answer to your question is my idea that the chart presents speed as Ground Speed. What it thus may show is the aircraft encountered significant winds shifted aloft.

Aircraft appears to have also made a significant course change, though if for weather avoidance or route requirements, I've no idea without a chart in front of me.

If the aircraft were actually below stall speed, the altitude would not have remained the same, since stall tends to yield a fall.

Presuming, as you note, a certain amount of accuracy in that table.

[GroundProxGuy]

Some aircraft have an Emergency Descent autopilot mode when cabin altitude climbs well above 8000 feet that turns the aircraft 90 degrees (to get off airway and bring ATC attention) and auto descends to 12,000 feet or so. During the descent their groundspeed would be lowered.

But if the crew was incapacitated and never recovered the a/c should just fly the new heading at 12,000 feet until fuel exhaustion.

Perhaps a fuselage failure initiated emergency descent mode and incapacitated the crew, followed a few minutes later by worsening damage sufficient to depart controlled flight?

[Huck]

Time of useful consciousness should have been over 3 minutes after an explosive D at 260.

But he had to have a working mask on his face by then, or have descended below 12.5 or so......

Time of useful consciousness - Wikipedia, the free encyclopedia

[Lonewolf_50]

Huck: my experiences with Hypoxia in training chambers showed me that at 25 K, it takes about a minute or so to get loopy, for some, and up to three minutes for others. Point? He could have been one of those who goes loopy faster if decompression was what happened.

A great many questions unanswered.

[ctrautve]

Question: can the PC-12's cargo door be opened at altitude?

[BobnSpike]

Food for thought. Not speculating, though.

Probable Cause #1: Breakup In Flight

Aircraft Accidents and Incidents - Wellsville, Missouri 63384 Thursday, June 28, 2007 8:15 AM CDT

[TampaSLF]

Missing passenger found

They fo0und the kid some distance from the impact site.
Officials find body of teen killed in Polk plane crash | TBO.com

[sevenstrokeroll]

so, could it have gotten into a thunderstorm, pilot over controlled trying to maintain altitude?

what is maneuvering speed in this pup, or it might be called rough air penetration speed.

does it really have an autopilot that will , upon loss of pressure, descend to 12,000 feet and perform an 90 degree change in course?

what do you do if you are over mount whitney and lose pressure? crash into a mountain??????

[MarkerInbound]

Don't know about the PC-12 but the Citation Mustang autopilot does have an ED mode. The pilot still has to close the throttles and extend the boards and gear. And they have to be functional at the level off altitude to add power and clean the plane up or you've just delayed the inevitable.

[Yankee Whisky]

PC12 Florida crash

Note the two wings are in the picture as is evidence of the propeller rotating in level ground contact. Seems to me the aircraft either fell to the ground in flat (spin ?) or forward speed condition.