Fuel Mixture Settings for the F4U Corsair

[-)-MAILMAN-]

In the game all of the F4U Corsairs have two mixture settings:

Automatic Rich=100%
Full Rich=120%

I just finished reading:

AN 01-45HA-1
"Pilot's Handbook of Flight Operating Instructions For Naval Models F4U-1 F4U-1C F4U-1D F3A-1 F3A-1D FG-1 FG-1D Airplanes British Models Corsair I II III IV"

(F4U-1 also includes the unofficial designation F4U-1A)

It explains that the mixture control had three effective positions:

Idle Cutoff
Automatic Lean
Automatic Rich

"The fourth position. "FULL RICH" has been or should be rendered inoperative, and therefore no attempt should be made to use it."

"IDLE CUTOFF was used to shut off the engine"

"For all flight operation, except take-off and landing, the control shall be set in "AUTO LEAN"."

""AUTO RICH" position shall be used for take-off, landing and all ground operations."


Any chance this gets corrected?
The quotes are right out of the 1944 Pilot's Manual for the P&W R-2800-8 & R-2800-8W. I haven't checked the F6F Manual yet.

[yak9utpro]

i think that it should be able to be corrected and allow 4 mixture settings since the yak9 has 6 settings (20% 40% 60% 80% 100% and 120%)

[Treetop64]

Problem with that is the Yak had a manual mixture setting. The pilot needed to always manually adjust the mixture according to aircraft configuration and altitude, and made for a high workload for the pilot. The +/-20 increments in the mixture settings used in the game is a simplified version of this.

According to which setting the pilot selected, the auto-mixture in the Corsair either automatically controlled the mixture at a rich setting, a lean setting, at full fuel flow, or stopped fuel flow at cutoff. The pilot did not need to constantly monitor and adjust fuel flow as the pilot in the Yak was required to do. With the Corsair and other Allied aircraft, I think the game just makes an expedient simplification by allowing the mixture settings to be set at either full-rich or an optimal lean mix setting; there is no separate rich or lean mixture setting or idle cutoff. This also means you must use the [I] key to shut down the engine, as opposed to moving the mixture lever to Idle-Cutoff to cut fuel flow.

In the in-game Yak however, you can cut fuel flow by moving the mixture setting back fully because it does not use the game's auto-mixture system.

"Fixing" this is probably more of a complicated issue than just considering the number of increments in fuel-flow settings, especially considering auto-mixture.

[-)-MAILMAN-]

The settings in the game for the corsairs are either full rich or auto rich. In full rich the engine bogs down and smokes above 2000 feet. Full rich did not exist in these birds and should not be in the game, period. Auto rich is what was used on take off and landing and Auto lean for flight operations. These should be the two choices in the game. There is a reason the throttles had the two settings and should have differing affects on fuel consumption and engine performance based on altitude.

[Treetop64]

Originally Posted by -)-MAILMAN-

The settings in the game for the corsairs are either full rich or auto rich. In full rich the engine bogs down and smokes above 2000 feet. Full rich did not exist in these birds and should not be in the game, period. Auto rich is what was used on take off and landing and Auto lean for flight operations. These should be the two choices in the game. There is a reason the throttles had the two settings and should have differing affects on fuel consumption and engine performance based on altitude.

Can't speak for the Corsair carburetor as I don't know first hand, but the Stromberg carburetors used on many US aircraft during the war (PD-12E on the F4F, and NA-R9B and C on the Grumman Goose, for example) had four settings, including full rich:

Full Rich
Auto Rich
Auto Lean
Idle Cutoff

Full Rich was for emergency use only.
Auto Lean was used for cruising in level flight.
Auto Rich was used for all other flight and ground operations.

As mentioned, the game takes many expediencies when it comes to simplifying systems modelling in it's aircraft, and it has been that way since day one.

[-)-MAILMAN-]

Well then since you are not familiar with the carburetor then I would kindly recommend finding and reading the Pilot's Manual that I put in my original post. They definitely did not have Full Rich enabled. I am aware there are expediencies in the game, but this was simply a request that an omission get corrected. They don't have to do it, but if I don't ask it probably never happens. Maybe they were unaware that the corsairs had this feature disabled. Over the years I have seen them correct omissions and mistakes and this is no different. Maybe they were unaware that they operated on automatic lean and used automatic rich only during takeoff and landing. It isn't like I just grabbed this theory out of thin air and threw it against the wall to see if it would stick. I also made sure that I provided the exact reference for the statements I quoted and they can check/verify this for themselves.

[majorfailure]

Does 120% mixture automatically correspond to full rich?
And what would happen in a real life Corsair if pilot would engage auto rich mixture above 2000m alt?

[-)-MAILMAN-]

Quote from majorfailure:

"Does 120% mixture automatically correspond to full rich?"

This is copied and pasted directly out of the IL-2 Manual:

"Mixture Control: Most of the engines allow the pilot to adjust mixture richness manually. While the nominal position of this control (Auto Rich) should provide normal engine operation in all flight configurations, some input may be required at high altitude or when the engine has taken damage in battle. It is common to use increased (Full Rich) setup during takeoff or as a means of emergency power."

In the game for the Corsairs, Hellcats, Wildcats this equates to Auto Rich = 100% and Full Rich = 120%.

The below information is taken directly from the Pilot Manuals issued to the Pilot's who flew the below aircraft and my reason for saying that full rich be removed from planes that didn't have it and auto lean added to the same planes. They felt a need to remove water injection from early corsairs and hellcats to be more accurate then the mixture settings should be more accurate as well. Maybe this will alter the performance for these planes or maybe it doesn't change a thing.

Corsairs, Hellcats

No Full Rich mix position and if the mixture control had the position it was disabled

Automatic Rich - Ground, Takeoff, Landing

Automatic Lean - All air operations

Idle Cut Off - Turn off engine

FM-2

No Full Rich position on mixture control

Auto Rich - Ground, Takeoff, Landing

Auto Lean - All flight operations

Idle Cut Off - Stop engine

F4F-4

Full Rich - used only if there is a failure to the Automatic Rich function

Automatic Rich - Ground, Takeoff, Approach, Landing, Air Operations

Automatic Lean - Used for cruising when power settings (RPM & MAP) are at 70% or less

Idle Cut Off - Stop Engine