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View Full Version : Oleg, F4U Fuel situation

VBF-83_Hawk
01-04-2005, 04:15 PM
I really have delayed posting this but thought I would go ahead with it.

<-----Gets out the flak jacket!

The F4U-1D fuel guage is marked in 10 gal increments up to 240 gals.
F4U-1D holds 237 gals.
With a load out of 25% fuel, the guage indicates 33 gals. 33x4= 132gal.
With a load out of 50% fuel, the guage indicates 66 gals. 66x2= 132 gals.
With a load out of 75% fuel, the guage indicates 99 gals.
With a load out of 100% fuel, the guage indicates 132 gals...not 237 gals.

Questions

1. Is the fuel guage bugged?
2. Why is the fuel fugured on 132 gals instead of 237 gals?
3. Will all this be fixed, if its wrong, in v3.04?
4. With the correct fuel load, will the weight be too much for any carrier ops?
5. Is the fuel consumption modeled correctly?

VBF-83_Hawk
01-04-2005, 04:15 PM
I really have delayed posting this but thought I would go ahead with it.

&lt;-----Gets out the flak jacket!

The F4U-1D fuel guage is marked in 10 gal increments up to 240 gals.
F4U-1D holds 237 gals.
With a load out of 25% fuel, the guage indicates 33 gals. 33x4= 132gal.
With a load out of 50% fuel, the guage indicates 66 gals. 66x2= 132 gals.
With a load out of 75% fuel, the guage indicates 99 gals.
With a load out of 100% fuel, the guage indicates 132 gals...not 237 gals.

Questions

1. Is the fuel guage bugged?
2. Why is the fuel fugured on 132 gals instead of 237 gals?
3. Will all this be fixed, if its wrong, in v3.04?
4. With the correct fuel load, will the weight be too much for any carrier ops?
5. Is the fuel consumption modeled correctly?

VBF-83_Hawk
01-05-2005, 05:26 AM
Anyone else notice this?

voyager_663rd
01-05-2005, 06:01 PM
Because you asked your question so nicely, I'll give you the answer: OLEG IS RIGHT (as he is most if not all times) and I'll tell you why.

Although the 1D had a 267 tank as you say, it was really 3 tanks: one in the fuse and one in each wing (the wing tanks being 63 gal each).

When the capability of adding the 154 gal external tank was added, the two wing tanks were deleted.

Well you say, that still leaves a discrepancy of 9 gallons to which I would say: just how accurate (to within 5% in this case) do you think painted lines with an arrow pointer are?

Oleg is bang on (again).

VBF-83_Hawk
01-05-2005, 10:15 PM

Even so, Olegs F4U-1D 100% Fuel is only 132 gals?

TX-EcoDragon
01-05-2005, 10:29 PM
Voyager nearly answered your question, but forgot to add that the Corsair only has a fuel gauge on the center (fuselage) tank, the wing tanks where to be used first. Endurance figures based on known power settings are more accurate than any fuel gauge anyway. . . ask any pilot how accurate his fuel gauges are and they will proabably tell you that they are very accurate. . . when empty :-D (ignoring these newfangled high tech computer equipped aircraft with fuel totalizers and such)

VBF-83_Hawk
01-05-2005, 11:12 PM
Are you sure the -1D had wing tanks?
I know it only had one guage and it is for the fuselage tank. I also know it had a (small 50 gal) reserve tank for takeoff and landing.

..and yes, fuel guages are for estamates, clock is for actual.

Flew tonight for one hour and burned 35 gals. Thats departing with 50% fuel, Oleg's 65 gals, Rockets and 3 500lb bombs. Climbing at 43'@2550rpm (155mph) up to 13,000ft in about 15 minutes. Then low blower 47"@2550 to 15,000ft in about 1 minute. Then max cruise to target 32"@2330rpm for about 5 minutes. On station 32"@2330 at 2,000ft and below in neutral blower for about 15 minutes. RTB up to 9,000ft in about 5 minutes 43"@2550rpm. Cruise at 32"@2330 for 10 minutes. Two aborted landings to attack kamikazi Ki-46s then landed.

Total Time Mission: 1 hour and a few minutes.
Now not knowing exactly what this thing burns at these power settings, I estimated fuel burn.

Climb out (normal climb power) estimated at 200 gal per hour for 15 minutes alone should have been about 50 gals. (thats departing, making one circle at cv for formup (5 minutes), then climb)

I am not saying anything is wrong, I just want to know what the numbers are that is being used.

And I will get to the landing light later. I know, piddly stuff!

voyager_663rd
01-06-2005, 09:09 AM
In a word: Yes.

More than a word: there are many sources of data available. This is an excerpt from one (not the one I used but in any case):

For the production F4U, the US Navy required some changes, which were logical in itself but had unfortunate side effects. More armour was carried for the pilot and oil tank, which added 68kg to the weight. The armament was changed to six .50 machine guns, three in each wing. The wing bomb bays were deleted. This increase in firepower was needed, but the wing guns displaced the leading edge fuel tanks. To restore an adequate fuel capacity, an additional fuel tank had to be installed in the fuselage. Because it had to be near the center of gravity, there was no other option than moving the cockpit to the rear. The 897 liter self-sealing fuel tank pushed to cockpit 0.91 meter closer to the tail. Forward view over the engine cowling, already poor in the prototype, was now decidedly bad.

http://www.americanairpowermuseum.com/htm/corsair.htm

DRB_Hookech0
01-06-2005, 09:20 AM
Ok, since there are 2 treads on this topic, I'll post what I added to the other tread.
This is the information I have from the F4u-1 flight manual (which lists info on the -1d model also)

Fuel - Grade 100/130 Spec. AN-F-28

Capacity (model F4u-1, F3a-1, FG-1, and Brit serial # Jt-100 to Jt-554)

Normal Fighter - 178 US gal. (75% full main tank only)

Overload Fighter (full tanks) - 363 US gal. (237 gal. main + (2) 63 gal. wings)

Overload Fighter (drop tanks) - 535 US gal. (237 gal. main + (2) 63 gal. wings + 170 gal. drop tank)

Capacity (model F4u-1d, F3a-1d, Fg-1d and Brit serial # Jt-555 and subsequent)

Normal fighter - 178 US gal. (75% full main tank only)

Fighter - 237 US gal. (100% full main)

Long Range fighter or fighter bomber - 391 US gal. (Full main + 154 gal. Navy Std. drop tank)

Long rang fighter - 545 US gal. (Full main + (2) 154 gal. Navy Std. drop tanks. Could go577 US gal. with full main + (2) Lockheed type 170 gal. drop tanks)

Tanks:
Fuel system for model F4u-1, F3a-1, FG-1, and Brit serial # Jt-100 to Jt-554
inclusive (prior to center section twin pylons installation) is shown in fig. 11.

The self sealing main tank, located in the fuselage, forward of the cockpit, has
a total capacity of 237 US gal. of fuel, including a stand pipe reserve of 50
US. gal.. Two wing tanks, built integrally with the outer panels, have a capacity
of 63 US gal. each. The wing tanks are provided with a CO2 vapor dilution system.
Provision is made, under the fuselage, for the installation of a droppable auxiliary
tank having the capacity of 170 US gal. The main fuel tank maintains a standpipe
reserve of 50 US gal. after the fuel supply thru the main line is exhausted. Bear
in mind that the reserve is made availible as the quantity necessary for final
operation before landing, when the main fuel supply is exhausted and noted below.

The fuel system for model F4u-1d, F3a-1d, Fg-1d and Brit serial # Jt-555 and subsequent
is shown in fig. 11A.

This system includes provisions for installing two Navy standard-type droppable tanks,
each with a capacity of 154 US gal. on the center section twin pylons. Lockheed-type
droppable tanks which have the capacity of 170 US gal. may be installed in place of
Navy standard-type tanks if the latter is not available. The orignal main tank and
provisions for installign s droppable tank under the fuselage are retained on these
airplanes. However, the two wing tanks and their vapor dilution system are eleminated.

VBF-83_Hawk
01-06-2005, 10:24 AM