Fuel tank for takeoff and landing

[av8orDave]

Any Corsair nerds know why the preferred fuel tank selection for takeoff and landing is the reserve tank rather than the main?

[JesseJames38]

Because the reserve draws from the bottom of the tank.  More fuel pressure by weight. If the fuel level is low in the tank less likely to run out of fuel on landing or takeoff depending on attitude of the aircraft.  

[Super Wabbit]

Is this why the engine shuts off when the Main Tank Fuel level drops below 50 gallons?

[Mike Busutil]

Yes

[Nealius]

Would the engine shut off with reserve selected and main below 50gal as well? 

[Sarge55]

Pretty sure I saw there was a fuel pump for these kind of fuel situations. Doesn’t it work?  I’ll have to check, thanks for pointing it out. 

[Mav87th]

A question regarding fuel tanks, or perhaps rather a confirmation question. Is it correctly understood, that the model in DCS (the -1D) where there are provisions for external tanks (right hand and left hand droppable tanks or centerline tank) AND that if any one of these are installed there are no wing tanks installed.

So if choosing external tanks in the loadout page, the wing tanks are automatically eliminated and if not there are no wingtanks installed. And i presume the same with centerline tank installation in the loadout screen.

Image in post should be of the wingtank configuration and the correct fuel selector valve 

null

[Mike Busutil]

The "Main" and the "Reserve" are the same fuel tank. (Main) The fuel pickup for the "Reserve" selector is just lower in the main tank allowing  to draw from the lower portion of the main tank, ensuring fuel availability when the main supply runs low. If you run out of fuel in the "Main" tank, you can select "Reserve" to start picking up fuel again. 

 

There are two fuel pumps in the Corsair:

• Engine-Driven Fuel Pump.

• Auxiliary (Booster) Fuel Pump

The primary fuel pump is an engine-driven pump, mechanically powered by the Pratt & Whitney R-2800-8W engine via an accessory drive.

This pump was responsible for delivering fuel from the main tank (or selected external drop tank) to the engine’s carburetor under normal operating conditions and directly tied to engine RPM, meaning fuel flow increased with engine speed.

In negative-G maneuvers or when fuel levels were low, the engine-driven pump could experience cavitation or fuel starvation, necessitating a backup pump.

The Auxiliary (Booster) Fuel Pump ensures positive fuel pressure during critical phases of flight, such as takeoff, landing, high-altitude operations, or combat maneuvers.

Prevented fuel starvation in situations where the engine-driven pump alone was insufficient, such as during negative-G maneuvers, steep climbs, or when switching between tanks (e.g., from drop tanks to main tank) and assisted in priming the engine during startup.

 

The wing fuel tanks, which were present in earlier models like the F4U-1 and F4U-1A (each holding 62 US gallons, unarmored, and non-self-sealing), were removed in the F4U-1D. This was primarily to reduce vulnerability to enemy fire, as these tanks were prone to leaks and fires due to their lack of armor and self-sealing features. Additionally, the removal saved weight and made room for the fighter-bomber role, which required mounting points for external ordnance like bombs and rockets.

In earlier Corsair variants, the wing tanks were located in the leading edge of the outer wing panels, outboard of the guns. These were primarily used for ferry missions and were often not filled during combat due to their vulnerability. By the time the F4U-1D was introduced in April 1944, the design prioritized external fuel options to compensate for the loss of internal wing tank capacity.

Edited July 1 by Mike Busutil

[Invisibull]

On 6/21/2025 at 4:42 PM, av8orDave said:

Any Corsair nerds know why the preferred fuel tank selection for takeoff and landing is the reserve tank rather than the main?

The reserve tank is positioned to ensure reliable fuel delivery during high-demand phases like takeoff and landing. Using the reserve tank in these critical moments helps avoid issues such as fuel starvation or vapor lock that could occur if the main tank's fuel lines or pumps were compromised or if the main tank was not full enough to ensure positive fuel pressure during rapid attitude changes.

[av8orDave]

4 hours ago, Invisibull said:

The reserve tank is positioned to ensure reliable fuel delivery during high-demand phases like takeoff and landing. Using the reserve tank in these critical moments helps avoid issues such as fuel starvation or vapor lock that could occur if the main tank's fuel lines or pumps were compromised or if the main tank was not full enough to ensure positive fuel pressure during rapid attitude changes.

This is the answer. Thanks buddy, greatly appreciated.

[Saxman]

7 hours ago, Mav87th said:

Is it correctly understood, that the model in DCS (the -1D) where there are provisions for external tanks (right hand and left hand droppable tanks or centerline tank) AND that if any one of these are installed there are no wing tanks installed.

No, it is incorrect.

The auxiliary wing tanks were only installed on the F4U-1 and 1A, including on aircraft that had plumbing for fuel on the center pylon. They were removed outright in the 1D because the tanks were almost never used in the field, so it just made sense to get rid of them. It and all subsequent Corsair models only ever had the fuselage tank regardless of which external tanks they were carrying.

[Mav87th]

Thanks Saxman. Cleared that up very nicely for me