PA31-350 Chieftain Fuel System

[Les Parson 99]

Could someone speak to the PA31-350 fuel system? The Carenado PA31 does not correctly model AUX tanks. What is the situation with the Chieftain? 

[KenG 492]

2 flexible bladders per side with the outer bladder holding 40 gallons and the inner bladder holding 56 gallons. Total aircraft fuel is 192 gallons of which 186 is usable. Normally each engine feeds off its respective side however you can crossfeed in emergencies. 

 

Two electric fuel quantity gauges overhead each indicating the quantity of fuel per side based on the tank selected by the fuel selector console. 

 

Per the POH Section 7.17.

[Les Parson 99]

So, if I understand correctly, you are able to Left Main, Left Aux, Right Main and Right Aux individually or simply Left and Right with the respective Aux tanks included per side? 

[KenG 492]

Not sure where you are coming up with the term "Aux" tanks. The fuel control and the POH labels the tanks as Left Inboard (INBD) and Left Outboard (OUTBD) and Right Inboard (INBD) and Right Outboard (OUTBD). You have two selector levers one for each engine, the right engine normally feeds from the right fuel system and the left engine normally feeds from the left fuel system.  

 

In my short testing, Alabeo did not get the fuel feeding correct. No matter how you set up the fuel levers the engines will always feed from the outboard tanks first then the inboard. The only thing the levers seem to do is cut-off fuel flow and switch the fuel gauge indication. I am sure this is due to a "limitation of MSFS" even though some freeware aircraft have complicated fuel control logic. 

[stans 702]

Not sure where you are coming up with the term "Aux" tanks. The fuel control and the POH labels the tanks as Left Inboard (INBD) and Left Outboard (OUTBD) and Right Inboard (INBD) and Right Outboard (OUTBD). You have two selector levers one for each engine, the right engine normally feeds from the right fuel system and the left engine normally feeds from the left fuel system.  

 

In my short testing, Alabeo did not get the fuel feeding correct. No matter how you set up the fuel levers the engines will always feed from the outboard tanks first then the inboard. The only thing the levers seem to do is cut-off fuel flow and switch the fuel gauge indication. I am sure this is due to a "limitation of MSFS" even though some freeware aircraft have complicated fuel control logic. 

Feeding from outboard tanks until dry, regardless of where the fuel selector is set, is how MS coded their flight simulators.  As you pointed out, some developers have added gauge coding that gets around this issue, but Alabeo and Caranado have never been known to do such things.  One anomaly in the Carenado Navajo was that the fuel gauges displayed the total quantity of fuel in each wing, not in each tank.  I presume, from your post, that Alabeo's gauge and selector at least displays the quantity of fuel in each tank.

[Les Parson 99]

Thanks for this info. I know of two aircraft that correctly model fuel management - Milviz C310R and Carenado C340 (I'm not sure on this one). 

I reached out to Alabeo prior to the Chieftain release to request and clarify the fuel situation; however, the standard Alabeo/Carenado response prevailed - Nothin. 

[StewartH 66]

Thanks for this info. I know of two aircraft that correctly model fuel management - Milviz C310R and Carenado C340 (I'm not sure on this one). 

I reached out to Alabeo prior to the Chieftain release to request and clarify the fuel situation; however, the standard Alabeo/Carenado response prevailed - Nothin. 

How about A2A's Comanche?  They seem to have modeled fuel management correctly, but what do I know?  I've never flown one in RL.