P-47D-40 Relative Weights

[Apeking]

I have been looking at the weights of various planes using the new E6B. I was curious as to the difference in weight between the four P-47 ammo/MG options.

I looked at a P47D40, with 100% fuel, sitting on the runway with the engine off. The weights are as follows:

P47D40:
6x.50, 1602 rounds
14263

6x.50, 2550 rounds
14557

8x.50, 2136 rounds
14559

8x.50, 3400 rounds
14951

I note that the lightest 8x.50 option is almost exactly the same weight as the heavy 6x.50 option. This does not necessarily mean that the two are equivalent - I am sure that the balance is altered, I don't fly the aircraft often enough to tell.

Just for the sake of thoroughness I can confirm that the 1,000lb bombs all weight exactly 1,000lb. And that the 500kg bombs for the 190A8 and 190F8 (which have different models - the F8's version looks chunkier) also weigh the same.

I also learned that a fully bombed-up, rocketed-up, fuelled-up, MGed-up P-47D-40 weighs more than a fully-bombed-up, rocketed-up TBM.

[Stoney74]

I think the difference in the weight of the .50 rounds is practically equal to the weight of the lesser amount of ammo plus the 2 extra guns.  My squaddie flew helos in the Corps, and he said they planned 25 lbs per 100 rounds for ammo, and 40lbs per gun minus the mount, IIRC.

[bozon]

Originally posted by Apeking
I also learned that a fully bombed-up, rocketed-up, fuelled-up, MGed-up P-47D-40 weighs more than a fully-bombed-up, rocketed-up TBM.

Did you look at a fully fueled and loaded P47-N?

[Apeking]

"Did you look at a fully fueled and loaded P47-N?"

An empty P47-N weighs 661 more than an empty P47-D40. A fully-fueled N weighs 1741 more than a fully-fueled D40. I tested this in the offline arena, with fuel burn set to 10x. I noticed that WEP in the P47-N actually reduces fuel burn.

If you take 50% fuel in the P47-N the aircraft weighs roughly the same as a fully-fuelled P47-D40.

Still less than a Space Shuttle.

[Stoney74]

Originally posted by Apeking
[BI noticed that WEP in the P47-N actually reduces fuel burn.
[/B]

Same engine in the F4U-4, except that its supercharged instead of turbosupercharged.  Also burns less fuel on WEP than WOT.  I think these are the only two aircraft in the game where this is the case.

[Benny Moore]

Is there any possible explaination why an engine should burn less fuel at higher manifold pressure?

[Stoney74]

Originally posted by Benny Moore
Is there any possible explaination why an engine should burn less fuel at higher manifold pressure?

Because the water being used to cool the cylinders replaces an equivalent amount of fuel.  I don't know how large the water tank was on the F4U-4, but the P-47N had in excess of 30 gallons of water for water injection.  It was actually enough to run WEP for 10-15 minutes, although its not modelled correctly in the game.  I have not read of any instances where a pilot ran it for that long continuously though, and, the POH limits WEP to 5 mins.  So, theoretically, a P-47N pilot could engage WEP a number of times during a mission.  Actually, he could even go to a WEP setting even after he ran out of water, but would quickly begin overheating the cylinder heads and potentially begin suffering from fuel detonation.  Its interesting that the water injection was linked to manifold pressure, as it would even begin to engage before the throttle was advanced full.  Anytime the manifold pressure approached a certain level, the water injection kicked in. Its a similar setup as the ADI systems they use during the Reno Air Races to cool the engines while they're running those insanely high manifold pressures.  When they're running, you can actually see the stream of the excess water mixture trailing behind the plane.

[Krusty]

I wasn't going to post about it, but I did the same when I was running numbers for the 190 series. I was going to keep them to myself, but since you've already postd about it: (100% refers to internal fuel)

P47D-40 8-gun (3400 rounds) 100%: 14951 lbs
P47D-40 8-gun (noAmmo) 100%: 13897 lbs

P47D-40 6-gun (2550 rounds) 100%: 14558 lbs
P47D-40 6-gun (noAmmo) 100%: 13767 lbs

P47D-40 6-gun light ammo (267 rpg) 100%: 14264 lbs

3400 rounds (8gun heavy) 50cal = 1054 lbs
1602 rounds (6gun light) 50cal = 497 lbs
1x 50cal round = 0.31 lbs
empty weight difference between 6/8 gun = 130 lbs
each Browning M2 = 65 lbs


EDIT: You only save 687 lbs going from 8-gun heavy to 6-gun light. Not as much as I expected, considering you're still nearly 15,000 lbs of aircraft.

[Mustaine]

Originally posted by Apeking
And that the 500kg bombs for the 190A8 and 190F8 (which have different models - the F8's version looks chunkier) also weigh the same.

according to HTC they do model the correct conversion 2.2 lbs / kg

a 500kg bomb weighs in at 1,100 lbs of explosive damage in game