How to carry 361 gallons in 6ZQ
6ZQ's fuel tanks hold 361 gallons. By careful design, practically every gallon is usable.
There is a 15 gallon header tank mounted just forward of the instrument panel on the starboard side (where there are no instruments). All gas flowing to the engine
flows through this header tank. As well as being connected to the fuel quantity indication system, the header tank has a clear sight tube showing fuel level. In level flight, this sight gauge is very accurate and allows Bill to complete long flights with confidence.
The two wing tanks were expanded during construction and wing mounted speed breaks were left off so as not to add weight or reduce fuel capacity. The wing tanks gravity flow to a pump manifold that has triple redundancy pumps that feed the header tank. These three tanks represent the stripped down configuration of 6ZQ.
For this mission, two tanks were added where the rear seat would normally be, one in the foot well and another on the rear spar. All tanks gravity feed to the pump manifold that feeds the header tank.
He removed the co-pilot seat and rudder pedals to add tanks in the foot well and in place of the seat. In the picture you can see that this is like flying with a really big guy who never moves.
Finally, two collapsible tanks are placed atop the aft seat tank.
Bill manages weight and balance by selecting which of the eight tanks is feeding the header tank. He can tell by the sound of the pumps or by the quantity of the header tank when the last drop of fuel has been scavenged from each tank.
The autopilot is not designed to work with this full fuel load and Bill must hand fly 6ZQ for the first few hours.