For Kelti, P-40 fuel tanks...

[Oglivie]

Good Day Kelti and Everyone,

I happened by your post at a cfs2 forum, and not being a member yet there I thought I may reply here at SOH.

The P-40E had three internal tanks. Two of which were at the wing center-section (fuselage). The forward tank is listed as the a center-section reserve fuel tank at 29.2 Imperial gallons (35 US gallons), and the center-section main fuel tank (aft of the reserve tank) at 42.1 Imperial gallons (50.5 US gallons). A third tank is located in the fuselage just aft of the cockpit and listed at 51.5 Imperial gallons, but my books inidicate this was a 52.1 Imperial gallon tank (62.5 US gallons).

Attached below is a cutaway drawing of a P-40E, obtained at skycorner (http://www.airwar.ru/indexe.html), that shows this arrangement.

More P-40 versions from my books:

P-40: 120-181 gallons in internal tanks (I think all internal).

P-40B (Tomahawk IIa): 120-160 gallons.

P-40C (Tomahawk IIb): First with drop tank provisions, 52 gallon DT. 134 gallons internal fuel.

P-40D (Kittyhawk I) and P-40E (Kittyhawk Ia): 148 gallons internal in three tanks, 170 gallon external ferry tank, 52 gallon combat drop tank. P-40D had four .50 cal. mg, P-40E with six .50 cal. mg.

P-40F thru M: 157 gallons internal in three tanks (I assume the fuselage tank was up'ed to 71.5 gallons), 170 gallon external ferry tank, 52 gallon combat drop tank.

P-40N-1 (Kittyhawk IV): The fastest and lightest of the P-40s (P-40, P-40B/C are listed at lighter weight). 122 gallons internal in two tanks (reserve 35 gal tank omitted), 170 gallon external ferry tank, 75 gallon combat drop tank. Four .50s in the wings (with two outer gun bays retained) and shipped with two extra .50s for the empty bays or replacement guns.

P-40N-20 (but I think it the P-40N-5 and later): Capable of carrying three 500 lb. bombs or three external ferry tanks. 159 gallons internal in three tanks (I assume the reserve tank was up'ed to 37 gallons). Also the combat drop tank I assume to be a 75 gallon tank. Total fuel for ferry is listed at 609 gallons in internal and external tanks.

I hope this be helpful. I'd be glad to look up any other info from my books if you have any further questions.

Regards,
Oglivie

 

[kelticheart]

Thanks!

Thank you Oglivie for your input!

The fact is that I am only trying to adapt MAPE fuel switches in my rework of Jay McDaniel's P-40E 2d panel to the number of fuel tanks actually included in the airfile, the sole responsible for determining how many tanks, their location and their fuel capacity in a CFS2 aircraft.

This data is entered in the airfile by the original designer, and I can only accept that. None among Malinowski's P-40 series reflect the tank layout you posted, as well as the new P-40 released by Lindsay Watts, the latter is way off that.

I was able to adapt Malinowski's layout of one main central tank and a droptank to LW's model just because the coordinates of both tanks differ very little in the two models. But I could not add the second ferry tank included in Malinowski's P-40s because I had no idea how it would impact the CoG of Lindsay's model.

This is the heart of the problem: adding tanks to reflect the historical layout is not an issue. MAPE fuel switches would cover any type of tank layout that stock fuel switches will never support. The issue becomes serious when flying an aircraft whose CoG is all screwed up by a different weight distribution and I don't know how to take care of it.

At any rate, I haven't released the 2d panel yet and I am quite open to suggestions.

Cheers!
KH :ernae:

 

[Oglivie]

You're welcome Kelti,

The CoG maybe an issue. Not sure about the P-40, but the P-51 in real life did have a CoG issue with the aft fuselage 85 gallon tank. It was used first for take off and climb until several gallons were eliminated from it before switching to drop tanks. If it wasn't, some very unwanted flying characteristics could be encountered with aggressive high g manuevering with the P-51.

For CFS2 (unlike real aircraft), all tanks in the air file could be set to zero lateral, vertical and longitudunal distance from the CoG and function without adversely effecting the flight handling.

Another interesting thing I found about CFS2 drop tanks is that if there are two drop tanks in the air file, the fuel from both tanks is there for the aircraft even if only one drop tank is added from the DP. The DP tank either uses the left or right air file drop tank quantity depending on the DP hardpoint mount's lateral positioning for the drop tank. The remaining air file drop tank quantity remains there as if it is part of the internal fuel. This can be confirmed by using a digital fuel quantity display gauge for the 2d panel. I have one I downloaded from somewhere that I used for checking this.

I only have the Malinowski P-40s to tinker with at this time, they seem to fly fine as you stated with the aft (ferry) tank full.

Regards,
Oglivie

 

[kelticheart]

Now we can do it!

Hi Oglivie,

hey, whaddyaknow, between the two of us we can come up with an historical fuel tank layout for any P-40 that's available for CFS2. Last night I suddenly recalled there are also the FDG2 ex-dware P-40E and the FS9 Iris P-40s converted by Peperez, my brain is really acting strange lately....:isadizzy:

Back to the topic:

......The CoG maybe an issue. Not sure about the P-40, but the P-51 in real life did have a CoG issue with the aft fuselage 85 gallon tank. It was used first for take off and climb until several gallons were eliminated from it before switching to drop tanks. If it wasn't, some very unwanted flying characteristics could be encountered with aggressive high g manuevering with the P-51.

Yes, it's one of the first thing I read about Merlin-powered Mustangs, as Allison-powered P-51A and Mustang MkIs were not equipped with it. Pilots were strongly advised to burn all fuel from it before facing combat.

....For CFS2 (unlike real aircraft), all tanks in the air file could be set to zero lateral, vertical and longitudunal distance from the CoG and function without adversely effecting the flight handling.

This is great, I wasn't aware of it! This could be the right answer to adding the missing tanks to the P-40E layout and meet the historical requirement.

Another interesting thing I found about CFS2 drop tanks is that if there are two drop tanks in the air file, the fuel from both tanks is there for the aircraft even if only one drop tank is added from the DP. The DP tank either uses the left or right air file drop tank quantity depending on the DP hardpoint mount's lateral positioning for the drop tank. The remaining air file drop tank quantity remains there as if it is part of the internal fuel. This can be confirmed by using a digital fuel quantity display gauge for the 2d panel. I have one I downloaded from somewhere that I used for checking this.

I only have the Malinowski P-40s to tinker with at this time, they seem to fly fine as you stated with the aft (ferry) tank full.

Yes again! This is exactly how the third ferry tank works in Malinowski's P-40s. My 2d panel rework reflects exactly this layout, but I will add this tank to Lindsay's P-40, and the others I mentioned above, setting x, y and z zero distance from CoG and see if the flight behaviour is affected.

Then, I'll try adding the remaining tanks according to the historical layout you described. If it's not historical, I'll delete Malinowski's fuselage ferry tank from the dps. How's that?

A question, how about the 170 gal. external ferry tank: was it carried ventrally like the 52 gal. combat tank?
I think we could use a white F4U droptank from Dbolt's or even one of Malinowski's P-47 various droptanks to simulate it, have you got any picture showing a P-40 equipped with it?

Thank you for your help!
KH :ernae:

 

[bearcat241]

Originally Posted by Oglivie
......The CoG maybe an issue. Not sure about the P-40, but the P-51 in real life did have a CoG issue with the aft fuselage 85 gallon tank. It was used first for take off and climb until several gallons were eliminated from it before switching to drop tanks. If it wasn't, some very unwanted flying characteristics could be encountered with aggressive high g manuevering with the P-51.

Yes, it's one of the first thing I read about Merlin-powered Mustangs, as Allison-powered P-51A and Mustang MkIs were not equipped with it. Pilots were strongly advised to burn all fuel from it before facing combat.

I also found that to be a curious note in my studies of the Mustang.

Not to digress this thread from the P-40 topic gentlemen, but although this nasty characteristic could bite at the most inopportune moment while in an offensive hard turn, it also had great defensive benefits when fighting at altitude where most of the P-51 escort missions began. If a bogey got close on a P-51's six and the alert P-51 pilot yanked the stick into a hard turn and kicked the rudder right, that half full center tank could easily force a wingover spinning stall that could drop him 1000 to 200 feet before recovery and leave his attacker scratching his head upstairs wondering where his target suddenly went to...a hard to follow manuever even if the attacker executed a tight split S.

The stock CFS2 Corsair and Hellcat also have this tricky characteristic in high G turns. But their shared drawback is slow roll rates and low rudder effectiveness, even at combat speeds, which lead to slow stall recovery. They either spin in on their own or become easy prey.

 

[Oglivie]

Hi Oglivie,
hey, whaddyaknow, between the two of us we can come up with an historical fuel tank layout for any P-40 that's available for CFS2. Last night I suddenly recalled there are also the FDG2 ex-dware P-40E and the FS9 Iris P-40s converted by Peperez, my brain is really acting strange lately....:isadizzy:

Hi Kelti,

You and me both. I seem to be on verge of multi-tasking lately, I don't know if me ole beany will keep up with it.

Back to the topic:

Yes again! This is exactly how the third ferry tank works in Malinowski's P-40s. My 2d panel rework reflects exactly this layout, but I will add this tank to Lindsay's P-40, and the others I mentioned above, setting x, y and z zero distance from CoG and see if the flight behaviour is affected.

Then, I'll try adding the remaining tanks according to the historical layout you described. If it's not historical, I'll delete Malinowski's fuselage ferry tank from the dps. How's that?

Well, it looks like a plan to go with for now. A plan can always be changed later upon new information or need.

A question, how about the 170 gal. external ferry tank: was it carried ventrally like the 52 gal. combat tank?
I think we could use a white F4U droptank from Dbolt's or even one of Malinowski's P-47 various droptanks to simulate it, have you got any picture showing a P-40 equipped with it?

Thank you for your help!
KH :ernae:

I do not know if I have any pictures of the 170 tank, only text articles. It was carried in place of the 52 gallon tank I think for ferry flights. I'll do some searching and see if I can locate a drawing or picture somewhere.

Regards,
Oglivie

 

[Oglivie]

I also found that to be a curious note in my studies of the Mustang.

Not to digress this thread from the P-40 topic gentlemen, but although this nasty characteristic could bite at the most inopportune moment while in an offensive hard turn, it also had great defensive benefits when fighting at altitude where most of the P-51 escort missions began. If a bogey got close on a P-51's six and the alert P-51 pilot yanked the stick into a hard turn and kicked the rudder right, that half full center tank could easily force a wingover spinning stall that could drop him 1000 to 200 feet before recovery and leave his attacker scratching his head upstairs wondering where his target suddenly went to...a hard to follow manuever even if the attacker executed a tight split S.

The stock CFS2 Corsair and Hellcat also have this tricky characteristic in high G turns. But their shared drawback is slow roll rates and low rudder effectiveness, even at combat speeds, which lead to slow stall recovery. They either spin in on their own or become easy prey.

Bearcat,

I'm always learning something new about these historical aircraft. There is much I missed about certain aspects of aircraft that has been written. Thanks for sharing this.

Regards,
Oglivie

 

[Oglivie]

I do not know if I have any pictures of the 170 tank, only text articles. It was carried in place of the 52 gallon tank I think for ferry flights. I'll do some searching and see if I can locate a drawing or picture somewhere.

Can't find a pic yet of the 170 tank (except for a Spitfire version, I don't know if the P-40 would have used a similar type tank or not). However, an alternative perhaps would be the Malinowski 150 tank. The P-40N apppears to list a slew of drop tanks used for it that included the 52, 75, 150, 170, and one source states two 225 tanks. The book I have just gives the max ferry fuel quantity, which is with the 170 tank (except P-40N-20). But I would think that a 150 tank is plausible for ferry.

I found more P-40 drawings on my PC I have from Skycorner. If anyone is interested, there is a lot of P-40 stuff there in their drawings section (see first post in thread). One drawing in the attached shows a P-40E-1 with two 225 gal tanks under the wings. The E-1 is an E model with a variety of British equipment (I think factory installed), which included a Brit radio. Although 225 tank provisions were made available for the P-40N, they were probably retro-fitted to a variety of earlier P-40 models.

Drop Tanks - 170 gal P-40 Tank
http://www.ww2aircraft.net/forum/technical/p-47-loadouts-14154.html

 

[kelticheart]

Bearcat,

I'm always learning something new about these historical aircraft. There is much I missed about certain aspects of aircraft that has been written. Thanks for sharing this.

Regards,
Oglivie

Let me join in thanking you, Bearcat! :salute: To be fully honest, I had secretly hoped you'd jump into this conversation, because I always enjoyed your historical knowledge about WWII military aircrafts!

In the meantime, a careful look at Malinowski's P-40 airfile let me discover his layout practically matches both of those two center wing section tanks, whose individual capacity, 35 US gal. for the forward one and 50.5 US gal. for the rear one, add up to exactly the 85.5 gal capacity found in Malinowski's P-40 Warhawk main fuselage tank.

I then proceeded splitting that tank into a primary (Center 1) and an auxiliary (Center 2) tank. The latter set at x, y and z zero distance from the aircaft CoG. Both Lindsay's and Malinowski's P-40Es flight behaviour wasn't affected at all, even after adding the 62.5 US gal. fuselage ferry tank behind the pilot in Lindsay's model.

The only consequence of my tinkering seems to be a dramatically increased range in Lindsay's model!

Am I on the right track?

Cheers!
KH :ernae:

 

[bearcat241]

Let me join in thanking you, Bearcat! :salute: To be fully honest, I had secretly hoped you'd jump into this conversation, because I always enjoyed your historical knowledge about WWII military aircrafts!

Like most of you guys here with regard to aircraft, i grew up mainly on the visual modeling side with kits, photos and drawings. The real details and depths of all this technical stuff eluded me for most of my life until i started flight simming in some of the same models i used to build. I guess that's what draws me more to the performance side than designing. But at some point i'd like to put more effort into that as well.

The only consequence of my tinkering seems to be a dramatically increased range in Lindsay's model! ...Am I on the right track?

Well, what other track is there? More gas equals more range, right buddy?

 

[kelticheart]

Like most of you guys here with regard to aircraft, i grew up mainly on the visual modeling side with kits, photos and drawings. The real details and depths of all this technical stuff eluded me for most of my life until i started flight simming in some of the same models i used to build. I guess that's what draws me more to the performance side than designing. But at some point i'd like to put more effort into that as well.

I can't wait to see someday an aircraft designed by you....

Well, what other track is there? More gas equals more range, right buddy?

I know, I guess I was only looking for a good ole' pat on the back.......

Cheers!
KH :ernae:

 

[bearcat241]

OK, here's your 'atta boy...:ernae:...LOL

I can't wait to see someday an aircraft designed by you....

Well, since you already have a head start on the flight model, maybe we'll design yet another P-40

CheerZ!