Fuel question

[PTK]

About six years ago there was an M20K that ran out of fuel and crashed a mile short of the runway at GED. Engine stopped on the base to final turn. According to the report 7 gal total fuel was drained out. No mention how much in each tank. I always wondered is there a minimum fuel quantity below which the engine can run out of fuel in a bank or otherwise? My POH makes no mention of anything related to this. 

[N201MKTurbo]

If your turn is coordinated, it shouldn't matter. If you slip, the fuel could slosh around in the tank.

[PT20J]

All aircraft have unusable fuel. The fuel pickup in each tank is slightly above the lowest point to avoid picking up contaminants. For the M20K, the TCDS lists unusable fuel as 48.59 lbs. or about 8 gal.

Remember that the ‘E’ on the fuel gauge doesn’t mean ‘Enough’.

Skip

[carusoam]

Peter, Know where your fuel pick-ups are...

They have been strategically placed at the back of the tank... close to the cabin...

This gives you the opportunity to have good fuel flow in the T/O and climb...

Staying coordinated is Good...

Staying nose up is good...

Nose down, and your plane gets quiet... it may be hard to even know the engine has quit...

Making attitude changes or tank changes will Still take up many seconds before any fuel arrives at the engine...

PP thoughts only, something I learned on a brief maintenance flight...
 

Best regards,

-a-

[larrynimmo]

My J model lists only 2.5 gallons as unusable...I thought the K has the same wing

1981 M20J

[PTK]

9 hours ago, PT20J said:

All aircraft have unusable fuel.

I was referring to usable fuel. The unusable doesn’t enter in the calculations. My question was is there's a minimum usable level? iow, is 100% of usable actually usable? Referring back to that M20K accident I mentioned, where did that 7 gal total that was drained come from? Was it part of the usable that couldn’t make it to the pickups or part of the unusable? 

[Deb]

From Section II Limitations of the Ovation 2 GX AFM (original release 12-11-07):

FUEL LIMITATIONS

-WARNING-

Takeoff maneuvers when the selected fuel tank contains less than 12 gallons (45.4 liters) of fuel have not been demonstrated.

[Yetti]

Three rules for flying.   Always land with an hour of fuel remaining, Don't fly through front lines.  No single engine pistons in the Colorado Rockies Mtns

[Bob - S50]

3 hours ago, PTK said:

I was referring to usable fuel. The unusable doesn’t enter in the calculations. My question was is there's a minimum usable level? iow, is 100% of usable actually usable? Referring back to that M20K accident I mentioned, where did that 7 gal total that was drained come from? Was it part of the usable that couldn’t make it to the pickups or part of the unusable? 

Yes, 100% of usable is usable, at least in level flight it is.  On my J not only will it burn all the usable fuel, it will burn a bit over half of the unusable.

[Phil EF]

Five of the seven gallons drained was not-usable.  Attitude, variation of pickup tubes are likely accountable for the other two. 

[steingar]

Of course, the other thing is we're supposed to change to the tank that's got our reserves along hopefully with some more fuel yet again.

[kortopates]

On 6/29/2020 at 6:32 AM, Bob - S50 said:

Yes, 100% of usable is usable, at least in level flight it is.  On my J not only will it burn all the usable fuel, it will burn a bit over half of the unusable.

Good to know Bob.

Also there was a fuel exhaustion emergency in an M20E over WA popularized by an AOPA ASI video, something like "Trapped on top?" that demonstrated that you get to more of the unusable fuel by pitching up to climb attitude.

The fuel pick up is towards the back of the tank, so after our M20E pilot had run out of fuel in level flight, as well as in the descent, he glided till he almost had the emergency field made except for a jet blast barrier in front of the runway. He pulled the nose up to avoid impact with the barrier and as he did the fuel pickup found fuel and the engine came to life to clear the barrier and land on the over side!

I wouldn't count on it, but something to remember.....