Initially, Lancair provided a 15 gallon belly tank with the turbine kit as standard.  They then offered an optional 35 gallon belly tank which I purchased and is on my plane. This was the standard factory designed system with the wings feeding the belly which feeds the engine.  Simple but some feel not a good design due to the fuel underbelly and perhaps more importantly the potential unporting of the engine if air gets in the belly tank or if fuel is low and the belly tank is not full and one flies a steep climb angle.  If fuel is low and burned out of the belly tank, one must give adequate time after refueling for the wings to empty into and refill the belly or be very cognizant of avoiding a steep climb angle for fear of unporting the engine. I generally try to consider the belly tank my reserves and land before the 112 gallons in the wings are gone or if I use some fuel from the belly tank wait a period of time, low deck angle on climb out, or preferably let her sit overnight rechecking the wings prior to next flight to make sure the wings are as full as I expected as fuel from the wings will refill the belly. 

John Cook and others have redesigned the fuel system as George pointed out so as to be able to pump belly fuel into the wing and my understanding is that there is also a small gallon or two header tank so as to avoid unporting. PERHAPS  this is a better system but in ways may be more complicated requiring more active fuel management with PERHAPS more to malfunction.

I have opted to keep the factory designed system for many reasons but would also like to know the integrity of the factory designed/provided belly tank in a gear up landing.  I have been told by a previous owner of Lancair that it is a nonissue and that the factory system is the best but.........

David Weinsweig

Propjet N750DW

Todd,

 

I presume you are asking if someone could make a gear up landing on one and not compromise the tank?

 

Jeff

-----Original Message-----
From: Robert R Pastusek <rpastusek@htii.com>
To: Lancair Mailing List <lml@lancaironline.net>
Sent: Fri, Mar 28, 2014 9:25 am
Subject: [LML] Re: Lancair IV-PT Accident Report

Todd,

Belly tanks to support the higher fuel consumption of the turbines, were a builder add-on, and are all different. Some were better-engineered than others, but there is no standard for them. This, and the associated fuel system plumbing for the turbine, are truly “builder option.”
Bob

Sent from my iPad