Drop Tank Release - Starves Engine

[JabbyJabara]

Took the Thunderbolt for a long distance flight - now that it has drop tanks. As per the manual you have to take off on Main, then externals and then use the AUX until near empty then back to main. When I used my belly tank up I transfered to Main tank to prevent the engine from starving of fuel.

 

When I jettisoned my belly tank - I then tried using the left wing tank with the Rheostat pump set to full. It starved the engine, When I tried switching back to main then selected the right drop tank, then back to external the engine died again.

 

I believe the issue is the jettison code believes that if one tank is jettison then all of them are gone - even though visually they are there. Looking at the P47D 25 to 35 variant manual it states that you should be able to selective jettison the belly and use the wing tanks.

[saburo_cz]

This is not bug, it is feature.

 

First, "Rheostat" has nothig to do with external fuel tanks, it is only power regulation for elecric-driven pumps in the main and auxiliary fuel tanks.

 

Fuel from external fuel tanks is "powered" by pressured air from the vacuum system pump`s exhaust and all three are connected to the same source of pressure.

So, if one is disconnect, by dropping one external fuel tank, whole system lost pressure and fuel can not be taken from remaining external fuel tank(s).

 

External fuel tanks must be drop together when all are empty (or when any of them is no more needed).

[SMH]

This is not bug, it is feature.

 

First, "Rheostat" has nothig to do with external fuel tanks, it is only power regulation for elecric-driven pumps in the main and auxiliary fuel tanks.

 

Fuel from external fuel tanks is "powered" by pressured air from the vacuum system pump`s exhaust and all three are connected to the same source of pressure.

So, if one is disconnect, by dropping one external fuel tank, whole system lost pressure and fuel can not be taken from remaining external fuel tank(s).

 

External fuel tanks must be drop together when all are empty (or when any of them is no more needed).

 

Really? Why? How does, say, the center tank being gone stop us from feeding from a wing tank? The selector valve should shut off the missing tank, no different than if it was still attached.

 

And how is that situation different from if we had only loaded wing tanks in the first place?

[saburo_cz]

The fuel selector valve DOES NOT switch pressure power for the pushing out fuel from the external fuel tanks.

It only switches particular tank`s supply lines to the "engine fuel system".

(all external fuel tanks are connected with two pipes, one for draw fuel and one for pressure air and the selector valve switches only one, with fuel not with air)

 

Pressure power for the pushing out fuel from the external fuel tanks has only one source, but three alongside outputs.

So if one output is open (e.g. when one external tank is drop) all pressure goes out from this open (disconnected) output (the easiest way, of course) and then there is now no pressure power to push out fuel from the remaining external tank(s).

If the external fuel tank is not carried, this line is close, so no lose pressure through it.

 

It does not matter which exactly tank is dropped, wing or bely, one goes out, remaining loses pressure and becames useless, that is how it works, and worked IRL.

Edited October 24, 2020 by saburo_cz