hopper theory & practice

[jzeigenfus at comcast.net]

Having hovered a helicopter and just watching for when the tank is empty, I can tell you that the main tank goes first and the reserve is the last to get used. The tank is used on a Heli to keep  bubbling down because any engine burp when inverted in a Heli is not a good thing. Orientation of the Heli or plane really doesn't change the status of where the fuel is because the main tank is the one that is being pressurized. JEZ

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Dave I think that your last couple of questions are what occur. If someone would put one in a hover for a few minutes to setup equilibrium it should lean once replenishment from the main tank becomes established in the new orientation, anyone want to try that? ;)

ronlock at comcast.net wrote:
Ive been a hopper tank diss-believer for years. I also wonder why many continue to report benefits. What's responsible for the benefit?
I'm in agreement with Nat, and what "I think" Jerry has said regarding the fuel system with a FULL hopper tank being a column of fluid, and the hopper would have no benefit.
Maybe hopper serves to eliminate foaming and bubbles? Do I understand heli pilots use hoppers for that reason?
In practice do we usually have some air in the hopper? Or do we usually have a hopper tank that is flexible? Might we be drawing from the hopper without replenishing from the main tank during a vertical? Then the hopper gets replenished during level lines?
Still wondering, Ron Lockhart
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> >Matt, 
> >With or without the hopper tank we still have a solid column of 
> >incompressible fluid for gravity and G's to play its tricks on. I 
> >contend if it runs ok with the hopper it will run just as well 
> >without. Nat 
> 
> Nat, 
> 
> While not exactly accurate as stated, your point is well taken. Your 
> hypothesis has some merit when the tank is full, but it falls short 
> anytime else (which is most of the flight). Adding just a small 
> amount of air causes the system to become compressible (just like the 
> brakes on your car). 
> 
> Jerry 
> -- 
> ___________ 
> Jerry Budd 
> mailto:jbudd at qnet.com 
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