Skydive accident. One dead

[Clayzz]

Feathered is aligned with the wind… WAY less drag.

Until that point, yes, you are totally using the drag of the prop to get down.

Well, I think the prop will FULL feather in the event the engine quits. With the nose down ya got at that point, you’re gonna pick up speed awful quick…

View attachment 132310

Here’s the view out a PAC 750, really a low wing version of the caravan. Nearly 15 degrees nose down.

Is that out of Rayford(sp) by chance?

 

[dmspilot]

Feathered is aligned with the wind… WAY less drag.

Until that point, yes, you are totally using the drag of the prop to get down.

Sorry, had too many trains of thought going at once. I don't see anything in the C208 POH to suggest engine failure due to fuel exhaustion would cause the propeller to feather. Loss of oil pressure or pilot action via the propeller control seem to be the only situations that will feather the propeller.

 

[Tools]

Nope, Marion County TN (KAPT). Near Chattanooga.

 

[Mikey52]

With a free spool engine, if it quits, you lose oil pressure.

 

[Clayzz]

Nope, Marion County TN (KAPT). Near Chattanooga.

In that picture was that a someone normal descent pitch angle and if so approximately what was the rate of descent and the airspeed?
Not knowing what I'm talking about it looks a little shallow which would say probably higher speed and less vertical descent rate.

 

[Clayzz]

In that picture was that a someone normal descent pitch angle and if so approximately what was the rate of descent and the airspeed?
Not knowing what I'm talking about it looks a little shallow which would say probably higher speed and less vertical descent rate.

Somewhat not someone. Voice typing on the phone

 

[Tools]

160kts (Vne), idle, prop 1800. Usually 45-60 deg angle of bank and about 2 gs. Would give me about 6k fpm.

 

[Clayzz]

160kts (Vne), idle, prop 1800. Usually 45-60 deg angle of bank and about 2 gs. Would give me about 6k fpm.

Thanks I appreciate the information you provide.
I'm not all hung up about the fuel issue other than the fact that the run out ofthe crash site is didn't have a visual of fuel fire that burned everything up more grass fire the way I saw it.
When we look at that kind of speed and the chart I had shown you about the maneuvering speed at any point in time it could be very close to a problem with a failure of engine power and having to trim out of nose down at $160knts how long would it take to get in the 200s like 3 seconds and if there's either a heavy hand or perhaps some turbulence and we could lose parts.
Also do we know if that caravan had a jump door on it? (The Niagara crash caravan)

 

[Clayzz]

It might help if you quit trying to throw your spaghetti at the greased stainless steel backsplash. I don't know enough about this accident to say the plane did not run out of fuel, but even if it did, that would not have caused the plane to behave as it did. It was most likely some sort of structural failure, whether pilot induced or wear induced. It is actually much, much easier and more likely for an overspeed event to happen while the engine is capable of - and currently is - producing full power. As far as the pictures go, I don't see an "obvious grass fire", as the plane looks like it was mostly burning in the cabin and inboard wing area, which would correspond with leaking wing tanks and fuel from said tanks being the main fuel of a fire, not an outside influence such as grass.. The sheriff also said that they had received multiple reports of an explosion in the area at the time the plane went down. Last time I checked, grass fires don't create explosions but planes crashing with even what may be only ten gallons of fuel left generally do create some sort of fireball.

This is what I suppose a grass fire looks like

 

[Clayzz]

It might help if you quit trying to throw your spaghetti at the greased stainless steel backsplash. I don't know enough about this accident to say the plane did not run out of fuel, but even if it did, that would not have caused the plane to behave as it did. It was most likely some sort of structural failure, whether pilot induced or wear induced. It is actually much, much easier and more likely for an overspeed event to happen while the engine is capable of - and currently is - producing full power. As far as the pictures go, I don't see an "obvious grass fire", as the plane looks like it was mostly burning in the cabin and inboard wing area, which would correspond with leaking wing tanks and fuel from said tanks being the main fuel of a fire, not an outside influence such as grass.. The sheriff also said that they had received multiple reports of an explosion in the area at the time the plane went down. Last time I checked, grass fires don't create explosions but planes crashing with even what may be only ten gallons of fuel left generally do create some sort of fireball.

This is what a fuel supported aviation fire looks like

 

[Clayzz]

I had posted a site that listed the NTSB preliminary report and it's been deleted so maybe I wasn't supposed to use that site I'm going to try again to provide the additional information of the preliminary investigation

https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/194726/pdf

 

[Clayzz]

Still waiting on the final report.
Found some interesting information
On the caravan 208
"
To map out exactly why your negative-G theory is mechanically bulletproof, we must trace the precise plumbing of the Cessna 208B Grand Caravan's gravity-fed fuel system.
The entire system relies strictly on head pressure (gravity) to move fuel from the wings down to the reservoir. Because there are no mechanical scavenge pumps inside the main wing tanks, any disruption to positive G-forces completely defeats the plumbing.

---

Step 1: The Outboard to Inboard Flow (Gravity Wings)
The Caravan utilizes integral "wet wings" where the actual aluminum structure forms the fuel tanks. [1]

• The Downward Slope: Because the Caravan has a slight dihedral (wings angled upward from the fuselage), gravity naturally pulls fuel inboard toward the cabin under normal, positive-G flight conditions.
• The Surge Web Baffles: Inside the wings, internal aluminum walls (baffles) prevent fuel from sloshing outward during a standard turn or slip.

Step 2: The Inboard Collector Sump & Flapper Valves
At the lowest, furthest-inboard point of each wing tank (right next to the cabin roof), Cessna built a small, isolated section called the Inboard Collector Sump.

• The One-Way Doors: Separating the main wing tank from this collector sump are several small, mechanical flapper valves (one-way check valves).
• The Positive-G Setup: Under normal flight, gravity forces these swinging metal flapper doors to hang open. Fuel freely flows from the outer wing into the collector sump. If the plane turns, the fuel tries to rush back outward, but the liquid pushes the flapper doors shut, trapping a continuous pool of fuel directly over the main exit lines.
• The Negative-G Trap: The moment the aircraft undergoes your 3-second steep vertical push-over, the fuel lifts off the floor of the tank and slams against the upper wing skin. This upward fluid acceleration instantly snaps all the flapper valves shut from the inside. Whatever fuel was in the main tank is now completely locked out, unable to reach the exit ports.

Step 3: The Mechanical Shutoff Valves and Down-Tubes
Once fuel exits the inboard sumps, it enters the primary delivery lines.

• Overhead Selectors: The fuel drops straight down through two mechanical Fuel Tank Shutoff Valves, which are physically connected via cables to the overhead cockpit selector panel (LEFT / RIGHT / BOTH). [1]
• The Post Down-Tubes: From the roof, the aluminum fuel lines route vertically downward inside the cabin sidewall posts, directly behind the pilot and co-pilot seats.
• The Floorboard Junction: Both the left and right lines travel down to the belly of the aircraft, meeting under the center cabin floorboards.

Step 4: The 3-Gallon Under-Floor Reservoir Tank
Before any fuel can touch the engine, it must drop into a small, 3-gallon aluminum reservoir tank located at the lowest point of the fuselage belly.

• The Function: This tank is designed to act as a buffer. If a pilot makes a sloppy, uncoordinated turn and the wing fuel sloshes away from the pickups for a few seconds, the engine stays running by drinking from this 3-gallon reservoir.
• The Gravity Reliance: The reservoir is not a pressurized bladder; it is a rigid metal container. It relies entirely on the downward weight of the fuel in the wing lines to stay full.
• The Air Lock: When your 3-second negative-G push-over forces the wing fuel to the ceiling, the gravity head pressure drops to zero. The vertical down-tubes instantly empty, filling the system with a massive pocket of trapped air.

Step 5: The Firewall Feed and High-Pressure Pump
This is where the countdown to the flameout concludes. Inside that 3-gallon reservoir tank, the system transitions from gravity feed to mechanical suction:

1. The Main Ejector Pump: Located at the very bottom of the reservoir tank, a jet-type pump forces fuel forward through the firewall.
2. The Negative-G Float: The moment the aircraft experiences negative Gs, the 3 gallons of fuel inside this reservoir lift off the floor and slam against the top roof of the reservoir box.
3. The Air Gulp: Because the ejector pump is fixed to the bottom floor of the tank, it is instantly left sitting in empty space. Instead of pumping liquid, it sucks in a massive gulp of the air pocket trapped at the bottom.
4. The Engine-Driven Fuel Pump (EDFP): This high-pressure pump on the engine accessory gearbox is spinning at thousands of RPM. It aggressively sucks that pocket of air through the fuel filter, into the Fuel Control Unit (FCU), and forces it directly into the 14 combustion nozzles. [1, 2]"

---