Milviz/Shrike F-86 Fuel System

[Hollister56]

Has anyone been flying the F-86 lately on long cross-country flights with the drop tanks full and notice that when you go to Outboard/Jettison, to burn fuel from the drop tanks that the fuel system continues to use internal fuel. It should only be using fuel from the drop tanks. I am flying it in FS2024 and can not remember if I had this issue flying it in FS2020. I do not have FS2020 installed at the moment. I was just curious if anyone else noticed this and can leave a comment.

 

[RobM]

I still have 2020 and 2024 installed, and confirm that in 2020, with external ranks selected, only the external tanks feed. In 2024, it looks like the
external tanks feed the wing tanks, which feed the aft tank, which feeds the forward tank. The forward tank always stays full until all other tanks
are exhausted. So I guess you can still use your drop tanks for a long distance flight in the F-86 in 2024, just not in the correct way.

 

[Hollister56]

Hello Rob,

Thank you for confirming that, as I could not remember. I know Shrike has not officially done a FS2024 upgrade yet. and not sure they will? I did leave a couple of comments on their Discord, but have not seen a responce yet from Slayer, who I believe works at Milviz/Blackbird/Shrike.

I was trying my luck at editing the [Fuel_System] in the Flight_Model.cfg folder using triggers, but no luck as of yet.

From my experiences using the F-86 in FS2024 is that the internal tanks burn down to Zero and then final the Drop Tanks are the last to empty. I know there has to be an easy fix for this in the fuel system if someones know what the heck they are doing. I have the fuel tank selector on Outboard/Jettison.

But the good news is I think I solved the aileron flutter and the S-Turning across the course. It flys spot-on now and it will even flying a nice coupled ILS approach. It would be cool if they added a Garmin 430 inplace of the gunsight with a clickable hotspot, which would be another really easy thing to do it you knew what you're doing. Similar to FlyingIron P-38/F6F.

Anyway, thanks again for the info,

Ed

 

[Hollister56]

I believe I have the fuel system working correctly now in FS2024.

The airplane feeds only from the drop tanks when on Outboard/Jettison.

The system logic is to burn the drop tanks down to 1 gallon remaining and then start sending the aft, and wing tanks to the forward tank. When those tanks are emptied the forward tank fuel is used and then you're out of fuel.

Once the Outboard Tanks Empty light illuminates you can switch the drop tank selector to All Tanks Off. Note that fuel will be fed from the internal tanks when the drop tanks are less than one gallon remaining no matter the position of the drop tank selector switch.

To make this work I added 3 shut-off valves to the system, one in the aft, and wing tanks that remain closed as long as there is greater than 1 gallon of fuel remaining in the left drop tank. Once the left drop tank is equal to 1 the system logic commands the 3 shut-off valves open and they feed the forward tank.

I have tested this on 3 flights and it works on my system.

I attached the new [Fuel_System] file and you will need to copy and paste this into your flight_model.cfg folder. I recommend creating a backup flight_model.cfg file before editing.

To do this, open up your flight_model.cfg folder and highlight and delete the [Fuel_System], then paste this one in it's place. Save the file and you are good to go.

Ed

 

[DennyA]

Awesome work, Hollister56! They should incorporate this into the next update.

 

[Hollister56]

I was reading the F-86 manual from the USAF relating to the fuel system, and after the drop tanks are empty, then the aft tank empties into the lower fuel cell, which is not modeled in the Shrike F-86, just a forward tank. The reason is to keep the c/g forward. The c/g of the F-86 varies, from 29 to 34 percent from empty tanks to a full load.

This new update will burn the drop tanks, then the aft tank, followed by the wing tanks and finally the forward tank, for FS2024.

Ed