If you think about it, this makes sense. When you climb, the return line at the back of the tank is now lower relative to the bobber/filler cap. So it does its job and drains the tank to a lower level. When you level out in cruise, the fuel pump brings the fuel level back up.
Respectfully, Chris McGeary, 3044H --- In [email protected], "Jim Truxel" <jimtru...@...> wrote: > > Folks, > > I have a question. When I climb out in the Coupe, 415C, at 70 MPH , I notice > the fuel stick in the header tank guage seems to get lower than normal. But > shortly after I level off, the fuel inidicator goes back to full normal > showing. We just installed a new cap and float. I was wondering if with full > power and at this climb angle the fuel pump was not able to pump fuel into > the header fast enough. We have had no problems with the bird in any other > area. > > First time we noticed this we got concerned and flew around the airport > before heading off on a flight. > > Is this normal ? Next time I will try a climb speed of 75 to see what that > does. > > Thanks, > > Jim > N3439H > KFDK > > > > ----- Original Message ----- > From: William R. Bayne > To: ercoupe list > Sent: Friday, March 26, 2010 1:04 PM > Subject: [ercoupe-tech] Re: Fuel starvation: > > > > I agree with Wayne that any coupe whose fuel system has the gascolator, or > fuel filter bowl (see Parts Catalog, p. 26, Item 54), mounted low on the > forward face of the firewall is subject to unanticipated fuel flow > interruption in the manner he describes. Some Forneys and coupes (not Alons) > have been retrofitted with this firewall-mounted gascolator by > well-intentioned but uninformed owners or mechanics. > > I agree that this would seem the most likely cause of the recent crash in > Portugal. > > Wayne's solution should be in the preflight checklist of any and all such > airframes. > > Regards, > > WRB > > -- > > On Mar 26, 2010, at 07:49, Wayne Woollard wrote: > > > Ed: > > I have advocated for many years that there is a serious problem with tha > architecture of the Alon fuel line routing. > > The problem shows up if the fuel line is shut off at the base of the > header tank, and work is done on the remaining fuel system, or if the header > tank is drained for any reason or if all the fuel is consumed and it is > refilled. > > A basic fact of hollow lines is the fuel weight is enough to create a > small amount of fuel pressure at the carburetor, but this is not enough > weight to allow an air "bubble" to pass. A bubble of air in the fuel line > will only allow a limited amount of fuel to pass by, and will act as a > partial restriction, although THE LINE IS NOT RESTRICTED!! > > This simple fact along with the fuel line routing to the Alon Gascolator > setup and beyond are the cause of many frustrating takeoff incidents, wherein > the equipment failure cannot be duplicated. > > If you push down the tail of an Alon to duplicate the "Takeoff" angle of > attack and you have recently refilled your fuel system, an air bubble can > occur between the output of the header tank and the input to the carburetor. > This "Can" be duplicated by draining the header tank, and the loop in the > fuel line at the carburetor input, then refilling the fuel tank and powering > up the airplane, go through all the check lists, and taking off on a 3 mile > long runway, such as Castle, and see for youself. Halfway down the runway at > an altitude of 200 feet the engine will quit from fuel starvation! Plenty of > room remaining to land, but not so at a "Normal" airport. > > Solution: Bleed the air from the fuel line connection to the carburetor > by disconnecting it and holding it to a position below the lowest point in > the fuel system till the fuel runs smoothly without air, and reconnect. > following all the safety procedures of course. > D. Wayne Woollard CPBE > o--iii---( >
