Student Pilot Loses Engine During Solo Flight And Nails The Emergency Landing

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Pops

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And sliced finger tips forever and boy do they sting when the glow fuel hits the cuts
On my favorite RC model I could hold it up vertical and adjust the needle valve and release and it would go straight up and go out of sight in about 9 seconds. Just put it in a flat spin to bring it back down in site.
 

Tiger Tim

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Not in a 150 at typical altitudes. Most flight schools tell the students to leave it full rich all the time to avoid problems caused by over leaning.
I had heard of the issue coming up in 172s, albeit rarely and a bunch of holes in the Swiss cheese need to line up for it to be an issue.

Let’s say you’re flying a three-hour cross country and leaving with minimum VFR fuel; destination plus thirty minutes reserve. Three and a half hours gas, calculated at the consumption rate given in the POH which assumes proper leaning. Your reserve fuel in this case represents 1/6 of the fuel needed to get to your destination, or about 15%.

In the example above if your engine at cruise RPM/MP and full rich burns more than 15% over the lean fuel burn, you won’t make the destination.

I know, I know, “But what about the fuel gauge?” Have those ever worked reliably in a light single? You know you dipped the tanks before departure and you know how long you’ve been flying and you know what the POH says fuel burn should be, so the gauges must be out of whack, right? Heck, they probably have been the whole time you’ve been training so far so why start trusting them now? That’s how people get caught out.

Like I said, a lot of stuff has to happen before there are real consequences but if it happened to you, you wouldn’t be the first.
 

Dan Thomas

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I know, I know, “But what about the fuel gauge?” Have those ever worked reliably in a light single? You know you dipped the tanks before departure and you know how long you’ve been flying and you know what the POH says fuel burn should be, so the gauges must be out of whack, right? Heck, they probably have been the whole time you’ve been training so far so why start trusting them now? That’s how people get caught out.
Fuel gauges in light aircraft work well enough when the airplane is new. Age and hours wear them out. An airplane tied down outside will rock in the wind a bit, and the fuel in the tanks will move around some and move the fuel sender and cause wear in its rheostat. Electrical connections get oxidized and cause erroneous readings. Floats degrade and sink. The gauge itself gets sticky and the fine wires in its electromagnets can fail. The circuit breaker that feeds it can get oxidation on its contacts and cause supply issues.

And those are just the system problems. The shape of the typical aircraft wing fuel tank makes accurate measurements nearly impossible. It's shallow and wide and long, so any fuel movement causes the fuel sender to move unreasonably. Because of dihedral, you can't have the sender in the center of the tank as in a car, to minimize such error; it has to be inboard so as to measure the remaining fuel. Pitch and uncoordinated turns cause error. Flying wing-low causes error.

Airliners use multiple senders in each tank and sum the results to get an accurate idea of fuel levels. That sort of thing adds weight, complexity and cost in small airplanes. A pilot is expected to be trained to dip his tanks and get an accurate reading of fuel, plan accordingly, and lean the engine properly.
 

Dana

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I always set the needle to peak rpm with the nose straight up, then it was slightly rich and just right in level flight.

On the original subject, in the video you can see that one tank is showing empty, the other something under 1/4. In a C-150 with only a "both" setting you don't want to run a tank dry!
 

Pops

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And with the fuel selector on both the tanks never feed exactly the same. One wing will be a little higher than the other in a slight crosswind and the higher wing will feed more fuel. Even if you have different lengths on the fuel line both tanks will not feed the same. On the SSSC the fuel lines from each wing tanks comes together 6" to the left of the center of the firewall and the left tank always feeds more that the right tanks when using both tanks as one time.
 

Dan Thomas

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On the original subject, in the video you can see that one tank is showing empty, the other something under 1/4. In a C-150 with only a "both" setting you don't want to run a tank dry!
Actually, in a high-wing gravity-feed system, fluid seeks its own level, and you can't get air to the carb if there's fuel in one tank and none in the other unless the tank with fuel has a leaky fuel cap, usually the right cap. The leaky cap will allow the low pressure atop the wing to pull fuel from the left to the right until the left is dry, and if the suction is great enough it will pull air through the system so that the carb gets nothing. It also requires that the cap be misaligned enough that the vent holes in it get their static pressure messed up. Normally, though, in such a situation a lot of fuel gets sucked overboard through that leaking (or missing) cap.

He said he was losing oil pressure. That shouldn't happen if the prop is windmilling, since the oil pump is still working. The prop stopped, which is hard to do in a 150 unless you slow it almost to the stall. I believe he either ran out of oil, or the pump failed, and the engine was seizing. Could be carb ice, but he had pulled the carb heat and the engine RPM was still surging erratically. Prop shouldn't have stopped anyway.
 

Dana

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Yeah, I don't understand why the prop stopped unless he got it too slow... but the pilot admitted he ran out of fuel.
 
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