[ve0kog]

Hi folks
I'm a new RV pilot (with a grin ) and while learning to fly it I ran into a fuel unporting effect.

I was in a full right rudder slip and at about 500 AGL the dynon HDX alerted about the fuel level.
It was a bit of an attention grabber because I was slipping with the "wrong" tank selected.

The engine did not quit and I don't know if the fuel was truly unported. but did not realize this can happen even with fairly full tanks.
Just wanted to share what the fuel levels looked like from the HDX data file

 

[Majorpayne317641]

Oh yeah it will do that! I’ve done it a few times. I just select the tank that’s on the up side of the slip if I have the brain bytes available. I will say that it only happens to me if I’m aggressively slipping with a low fuel state. The engine will stumble.

 

[JonJay]

I’m shocked that you could unport a tank with 12 gallons of fuel in a forward slip.
Are you sure your fuel level sensors are reading correctly?
One way to mitigate this from happening is to crab until you’re closer on final and then enter your slip. However, you need time to establish a stable approach so I’m not saying you did anything wrong.
Good learning experience. Thx for sharing.

 

[ve0kog]

Are you sure your fuel level sensors are reading correctly?

I think the sensors are reading low, but accurate when empty. They cap at 14 and 15 gal in the EMS profile when full. I'm glad the HDX alerted a little ahead of time. It was an audible alert "FUEL LEVEL" and probably something on the screen, but I wasn't looking at it.
i cancelled the slip and went around. When I glanced at the fuel gauges a few seconds later they were both in the green as if nothing happened.

 

[dmattmul]

I think the sensors are reading low, but accurate when empty. They cap at 14 and 15 gal in the EMS profile when full. I'm glad the HDX alerted a little ahead of time. It was an audible alert "FUEL LEVEL" and probably something on the screen, but I wasn't looking at it.
i cancelled the slip and went around. When I glanced at the fuel gauges a few seconds later they were both in the green as if nothing happened.

Somehow deciding not to land when one gets an audible "fuel level" seems dicey. I've done a full slip both left and right 5 gals in my 14 (25 gals a side) and never a cough or drop in fuel pressure. I'll repeat the test. Also 25-degree bank 5 gals no issue. I have seen oil pressure drop 5-10 psi when in a slip when I'm below 5 qts.

 

[PilotjohnS]

You list o360 as engine, not IO. I have slipped angressively before with the up wing tank selected and the fuel gauge going to zero. I did not unport the fuel pickup becuase i never got a stumble from the entrapped air in my injected engine. I think to unport a fuel pick up in a slip the fuel has to be pretty low, like too low for safe operation in normal flight.

 

[ve0kog]

I have slipped angressively before with the up wing tank selected and the fuel gauge going to zero. I did not unport the fuel pickup becuase i never got a stumble from the entrapped air in my injected engine

This is probably what happened to me as well. The builder of my RV mentioned that the sensors are located higher than the fuel pick up, but he had never had this type of alert from HDX. I did not know either there was one for the low fuel

 

[Majorpayne317641]

You list o360 as engine, not IO. I have slipped angressively before with the up wing tank selected and the fuel gauge going to zero. I did not unport the fuel pickup becuase i never got a stumble from the entrapped air in my injected engine. I think to unport a fuel pick up in a slip the fuel has to be pretty low, like too low for safe operation in normal flight.

What is too low for safe operation in normal flight? Why can’t I have 20 gallons in one tank and 3 in the other?

 

[MarkW]

I had this happen with a 9. I was low and slow slipping for a good view of the river and the engine quit. I was probably 1/2 tank.
Quick lesson that will not be repeated.