Left wing dip

[minibikerider]

Yesterday, I was mid cruise going from Ann Arbor municipal (Go Blue) down to Texas. I ran into some icing condition through Ohio. My question is, why did my left wing just basically dip. I was burning off the right wing tip tank. But burning off the main left wing tank as well.

[mallcott]

Need hugely more information for a complete analysis.
Sim?
Weather Engine?
METAR at the time?



In general, wings dip because of unbalanced loading, active or passive. This may be caused by:
Aerodynamic effects (ice, mistaken handling of controls)
Weather (microburst, thermal, gust etc)
Loading (change in CG or load shifting)


I can't think of a reason why you would be running off the tip tank on one side and the wing tank on the other, unless you had already use the fuel in the tip tank on that side. In which case that's bad planning of fuel loading or usage on your part so it would be useful to know how you found yourself in such a position?

But mostly I'd point a finger at your weather engine...

[minibikerider]

I use active sky next for my weather. Up here in the Midwest, we've been starting to get some snow again. GL temp has been around mid 30- low 40. Of course the higher you go up the colder you get. I think I saw -20 degrees Fahrenheit when I was cruising at 10000ft on the temp gauge in the window. Tops of the clouds were higher than 10000. Ceiling was 700ft Agl at most.

Hope this gives a better picture into the possibility.
Also, I was able to land her at an airport somewhere in Ohio. Will be taking her back up later today. Gonna fill all tanks again, and burn both tip tanks at the same time and see if that doesn't cause my left wing to dip.

[William Hughes]

Mr. Piper generally intended those fuel tanks to be burned one at a time. There is no mechanism to keep the flow even. I don't know if the simulation models this but irl the flow could come from one or the other depending on venting and how level you keep the wings. You could even pull one dry and have the engine suck air while the other tank has fuel in it.

I tried cross feeding in the air once from a tip to a main (thought gravity would flow down) but the pressure from venting actually pushed fuel from the main up into the tip.

Generally, you want to switch tanks every 30 minutes to keep it even. I'll draw the right tip for 30 minutes, the left for an hour, then switch back to right till it's empty, and then finish the left. The yoke can get a bit heavy at the edges and if it is bugging me I'll switch every 15.

The mains don't cause so much hassle on out-of-balance flight.