How to read Spitfire Mk.XIV fuel gauge

[TAIPAN_]

Hi Guys,

 

Looking at the fuel gauge I haven't figured out how to read it properly yet.

I've read that the XIV has 2 main tanks holding 84 gallons together, then another 12.5 gallons in each wing.

That hasn't helped me understand the fuel gauge though

 

I can only assume that they represent the 2 main tanks - the front tank and rear tank.

Reading http://www.drivehq.com/file/df.aspx/publish/vvjack/wwwhome/spit14.pdf

It seems that the left gauge is the Rear Tank, and the right gauge is the Front/Main tank.

 

Also the 2x12.5 gallon wing tanks feed into the main front tank.

 

Does anyone know:

1. Do the wing tanks drain first into the main tank - i.e. the needle won't move at all until the wing tanks 25 gallons has been consumed? Unless you didn't take full fuel..

2. It looks like the needle on the right gauge must move counter-clockwise?

3. Does the rear tank or the front tank drain first?

4. Does the needle on the right move first i.e. Is that showing it draining from 84 gallons total main fuel down towards 50?  Or is it always showing total fuel and it will move even if the rear tank drains first?

 

[41Sqn_Skipper]

The right needle moves counter-clockwise from "F" to "50". Then it stops. Then the left needle starts moving counter-clockwise from "50" to "0". Then your engine stops.

Edited October 7, 2021 by 41Sqn_Skipper

[Bremspropeller]

Seems like we have to change our position on the rather weak german intelligence and counter-intelligence during the war.

Turns out, they ran the cockpit-design departments in several british aircraft companies...

[41Sqn_Skipper]

The right gauge shows the content of the upper tank, and the left shows the content of the lower tank. It's just that the numbers read the combined amount.

There is no gauge for the wing tanks, instead they can be switched on to feed to the upper tank once the needle is at the red mark (basically when there is enough space in the top tank for the fuel from the wing tanks).

 

There is no rear tank in Mk XIV, only in PR XIX. 

Edited October 7, 2021 by 41Sqn_Skipper

[TAIPAN_]

Awesome thanks guys.

 

I'm guessing IL-2 will automatically switch the wing tanks on and it would sit at the red line for a bit longer.

2 hours ago, Bremspropeller said:

Seems like we have to change our position on the rather weak german intelligence and counter-intelligence during the war.

Turns out, they ran the cockpit-design departments in several british aircraft companies...

Not just the cockpit When it comes to the Spitfire..

[ZachariasX]

13 hours ago, Dan_Taipan said:

Looking at the fuel gauge I haven't figured out how to read it properly yet.

In English planes, instruments read you.

[Jade_Monkey]

6 hours ago, Dan_Taipan said:

I'm guessing IL-2 will automatically switch the wing tanks on and it would sit at the red line for a bit longer.

 

For now yes. They are working on more advanced fuel systems and droptanks. This may or may not change when that is introduced.

[Halon]

I like it, it starts to give you a more accurate reading the closer to gliding you get!

[Kurfurst]

Such instruments are, in fact, perfectly logical, like having a seperate water taps in your bathroom, one with ice cold water, and one hot enough to melt your skin. 

[javelina]

On 10/7/2021 at 12:58 AM, Bremspropeller said:

Seems like we have to change our position on the rather weak german intelligence and counter-intelligence during the war.

Turns out, they ran the cockpit-design departments in several british aircraft companies...

gotta admit, that is funny! 

[NZTyphoon]

On 10/7/2021 at 9:13 PM, 41Sqn_Skipper said:

The right gauge shows the content of the upper tank, and the left shows the content of the lower tank. It's just that the numbers read the combined amount.

There is no gauge for the wing tanks, instead they can be switched on to feed to the upper tank once the needle is at the red mark (basically when there is enough space in the top tank for the fuel from the wing tanks).

 

There is no rear tank in Mk XIV, only in PR XIX. 

 

The F.R Mk. XIVs had a fuselage tank: however, according to the 1946 vintage Pilot's Notes:

 

Quote

NOTE - Except for special operations, as directed by the appropriate Operational Commander, the rear fuselage tank is sealed off and is not to be used

 

this was because of the marginal longitudinal stability that developed with the combination of cut down rear fuselage and 'bubble' canopy, plus full rear fuselage tank.

 

 

As to fuel tank management, the pilots were instructed to:

Quote

On F. Mk. XIV aircraft (and after emptying the rear fuselage tank on the F.R. Mk. XIV) transfer the fuel from one of the wing tanks when the contents of the top main tank fall to the red mark on the gauge. After 3 minutes return the transfer valve selector cock to NORMAL, then transfer the fuel from the second wing tank and after a further 3 minutes return the selector cock to NORMAL again.

 

Thus, the wing tanks were used as reserves, with the contents being pumped to the lower main fuel tank once the fuel level in the upper main tank was low enough: presumably this prevented air being introduced into the fuel lines, with possible fuel starvation at an embarrassing moment.