PC12 down in Nevada
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PC12 down in Nevada
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The upset here happened promptly, and the IFLOC went into a severe vertical departure pretty promptly. Those are very high rates of descent for an aircraft of that design. The GS is modest as the descent angle is very high, CAS is high. The system architecture and the availability of ADSB data suggest that electrical failure/instrument failure is unlikely the primary cause, flight crew incapacitation by hypoxia is unlikely at the relatively low altitudes that this occurred at, it hadn't spent great time above 10K, and stuff went odd at 05:11:41z and bad around the 19,000' - 19,400' reported altitude range. Flight crew incapacitation from an emergency medical event is another matter.. Spatial disorientation in turbulence may be a factor as it can always be.
An initial inflight break up would be a possibility, the RH outer wing panel would be a target for close scrutiny, but this aircraft would most likely have failed in flight later, close to the final impact point, it would be surprising if all pieces came to rest at the one location anyway. Pilatus make a strong aircraft, but rotors and waves can make for bad days out.
Sad end to an intended lifesaving exercise.
Juan's analysis on Blancoliro raises some interesting points, that is the right hand turn at 05:11:41z has hallmarks of a spatial disorientation event. SPIFR, in turbulence and accelerated flight, particularly with rain/snow impacts on a windscreen, and with light reflection off cloud layers, getting disorientated is quite possible. It's unpleasant enough multi crew, but single pilot, it's nice to have a good APLT and a really nice set of ADIs and standby's.
An initial inflight break up would be a possibility, the RH outer wing panel would be a target for close scrutiny, but this aircraft would most likely have failed in flight later, close to the final impact point, it would be surprising if all pieces came to rest at the one location anyway. Pilatus make a strong aircraft, but rotors and waves can make for bad days out.
Sad end to an intended lifesaving exercise.
Juan's analysis on Blancoliro raises some interesting points, that is the right hand turn at 05:11:41z has hallmarks of a spatial disorientation event. SPIFR, in turbulence and accelerated flight, particularly with rain/snow impacts on a windscreen, and with light reflection off cloud layers, getting disorientated is quite possible. It's unpleasant enough multi crew, but single pilot, it's nice to have a good APLT and a really nice set of ADIs and standby's.
Last edited by fdr; 26th Feb 2023 at 02:13.
An "ear-witness" heard the plane overfly her house, the last few seconds of its trajectory, with a high pitch engine noise and several 'backfire' sounds, before the final thump noise.
They tried to locate it in the surrounding fields, but it was snowing and low visibility, and passed by a few times 20ft or so away, without finding it (so I presume no post impact engine fire - not implying fuel starvation)
They tried to locate it in the surrounding fields, but it was snowing and low visibility, and passed by a few times 20ft or so away, without finding it (so I presume no post impact engine fire - not implying fuel starvation)
Interesting video. He raises the correct question. Why make this flight? Terrible weather, night , heavy turbulence, icing, single pilot. Why not wait till the morning? If history is any guide in the am it was VMC.
Reno has big hospitals etc , hard to know what SLC has that justifies this move.
An astounding 50% of life flight operations are pre scheduled patient transport.
Where I live, in the mountains, there is an astounding number of life flight helicopter moves for non urgent care.
We will likely never know why that flight was made.
Very sad.
Reno has big hospitals etc , hard to know what SLC has that justifies this move.
An astounding 50% of life flight operations are pre scheduled patient transport.
Where I live, in the mountains, there is an astounding number of life flight helicopter moves for non urgent care.
We will likely never know why that flight was made.
Very sad.
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The last data point I see has a ROD of 25984 ft/min, which works out to 295MPH, or 256kts. Of course CAS is lower, but that's just the vertical component and Vne is 236kts--the PC12 is not a slippery speedster. I'm assuming this plane did not arrive at the ground in one piece.
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the vertical component and Vne is 236kts--the PC12 is not a slippery speedster. I'm assuming this plane did not arrive at the ground in one piece.
But then it doesn't look like a helicopter either....
5-dead-after-careflight-helicopter-crashes-near-stagecoach
Some scene pictures I see (in daylight) seem to show the cabin ended up relatively intact (although somewhat flattened vertically, and with the cockpit separated at the bulkhead). But no crater filled with shredded aluminum.
Not consistent with most the VVIs recorded, which to me implies:
1) break up in flight, with the cabin/fuselage then falling approximately level at a lower terminal velocity, and belly-flopping.
2) almost successful last-second pull-out for which there was not enough altitude or time (violent belly landing).
3) attempted pull-out resulting in (1)
Note that I'm NOT denying the recorded VVIs, just that there may have been a change in the dive in the last few seconds. Or the ADS-B transmitter was falling at one speed, and the separated cabin at a slower speed at impact.
Not consistent with most the VVIs recorded, which to me implies:
1) break up in flight, with the cabin/fuselage then falling approximately level at a lower terminal velocity, and belly-flopping.
2) almost successful last-second pull-out for which there was not enough altitude or time (violent belly landing).
3) attempted pull-out resulting in (1)
Note that I'm NOT denying the recorded VVIs, just that there may have been a change in the dive in the last few seconds. Or the ADS-B transmitter was falling at one speed, and the separated cabin at a slower speed at impact.
Exactly. We have a good picture of the gross situation (LOCA spiral), but the NTSB will have to sort out all the possible contributing factors (e.g. A/P - did it kick off due to turbulence, or just choose a really bad time for an old-fashion electronic fault? Was there an AH failure?)
An "ear-witness" heard the plane overfly her house, the last few seconds of its trajectory, with a high pitch engine noise and several 'backfire' sounds, before the final thump noise.
They tried to locate it in the surrounding fields, but it was snowing and low visibility, and passed by a few times 20ft or so away, without finding it (so I presume no post impact engine fire - not implying fuel starvation)
They tried to locate it in the surrounding fields, but it was snowing and low visibility, and passed by a few times 20ft or so away, without finding it (so I presume no post impact engine fire - not implying fuel starvation)
Could be the sounds of break-up in the air - wings or tailfins snapping off. And/or hitting the ground before the rest of the plane "thumped."
Could be compressor stalls (which are, in effect, backfires) in the turboprop engine due to disruption of intake airflow by overspeed, or ice blocking the intake).
Could be compressor stalls (which are, in effect, backfires) in the turboprop engine due to disruption of intake airflow by overspeed, or ice blocking the intake).
NTSB says the plane broke up in flight:
https://www.kolotv.com/2023/02/25/ca...s-lyon-county/
The path shown in post #7 shows a spiral descent of approximate diameter 1/2 mile. The distance between Seneca and Seminole roads is 1/2 mile according to my guestimate from Google Maps
https://www.kolotv.com/2023/02/25/ca...s-lyon-county/
NTSB Vice Chairman Bruce Landsberg said an outboard section of the right wing a horizontal stabilizer and an elevator broke off before the crash. They were found about a half mile to three-quarters of a mile away, Landsberg said.
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An ex Life Guard pilot in the same area as this accident happened. Among many flying jobs I have done, I believe air ambulance job is the most rewarding as well as demanding. Except some air ambulance operators in Canada which use Metro or B1900, almost all turboprop aircrafts in this industry are flown by single pilot. In some cargo operations, B1900 was approved for single pilot ops as well in the US as far as I know. So, it can be done. I am afraid the industry won't change their practice of single pilot in PC-12 after this accident, regardless of the finding of NTSB investigation.
It is easy to get pumped up and become too mission oriented in air ambulance ops. While we learned about the White Knight Syndrome of the early days of Medivac ops, it ain't easy to say "No, we can't take-off in this weather." to the flight nurses and patient, and his/her family who occasionally shows up to the airport.
Sad day, indeed.
It is easy to get pumped up and become too mission oriented in air ambulance ops. While we learned about the White Knight Syndrome of the early days of Medivac ops, it ain't easy to say "No, we can't take-off in this weather." to the flight nurses and patient, and his/her family who occasionally shows up to the airport.
Sad day, indeed.