WI: NACA Modified P-38

Honestly, the more I look at it, the more it appears this divergence created something of a "worst case scenario" the Japanese fleets. Details in the narrative will be brief but I can include a supplemental sub-chapter covering the broad narrative of the actions off Samar afterward if there is enough interest.
 
I haven't been able to find specific numbers of torps available to the CVEs at the time but this little comment in the Battle Experience Report from the Taffys (Carrier Task Group 77.4) seems to imply a mere nine (!) aerial torpedoes per CVE.


Looking at the Order of Battle for CTG 77.4, Sprague had the following CVEs available to him:
  • Task Unit 77.4.1 (Taffy-1)
    • CarDiv 22
      • CVE-26 Sangamon (17 F6F, 9 TBM)
      • CVE-27 Suannee (22 F6F, 9 TBM)
      • CVE-29 Santee (24 FM-2, 9 TBM)
    • CarDiv 28
      • CVE-80 Petrof Bay (16 FM-2, 10 TBM)
  • Task Unit 77.4.2 (Taffy-2)
    • CarDiv 24
      • CVE-62 Natoma Bay (16 FM-2, 12 TBM)
      • CVE-61 Manila Bay (16 FM-2, 12 TBM)
    • CarDiv 27
      • CVE-77 Marcus Island (15 FM-2, 11 TBM)
      • CVE-76 Kadashan Bay (15 FM-2, 11 TBM)
      • CVE-78 Savo Island (16 FM-2, 12 TBM)
      • CVE-79 Ommaney Bay (16 FM-2, 11 TBM)
  • Task Unit 77.4.3 (Taffy-3)
    • CarDiv 25
      • CVE-70 Fanshaw Bay (16 FM-2, 12 TBM)
      • CVE-63 St. Lo (17 FM-2, 12 TBM)
      • CVE-66 White Plains (16 FM-2, 12 TBM)
      • CVE-68 Kalinin Bay (16 FM-2, 12 TBM)
    • CarDiv 26
      • CVE-71 Kitkun Bay (14 FM-2, 12 TBM)
      • CVE-73 Gambier Bay (18 FM-2, 12 TBM)
So, assuming all three Taffys (Task Units 77.4.1, 77.4.2, 77.4.3) are able to take part at various stages there could be as many as 178 TBMs available with 144 Torpedoes between them. Of course, I wouldn't expect a 100% serviceability rate but it should be pretty close considering most of the "dud" airplanes were loaded onto Saginaw Bay and Chenago at 1645 on 10/24 and sent to Morotai, with the remaining good aircraft from these two sent to back fill where needed throughout the rest of the CTG. Mind you, not all of these would be attacking at once, but in irregular waves from about 0700 until 1100 +/-. It should still be enough of a threat to make Kurita think twice about pressing forward.
Thanx for the extremely quick answer. So, one real attack per jeep carrier, then bombs, rockets, and strafing...
 
Honestly, the more I look at it, the more it appears this divergence created something of a "worst case scenario" the Japanese fleets. Details in the narrative will be brief but I can include a supplemental sub-chapter covering the broad narrative of the actions off Samar afterward if there is enough interest.

Yes, please
 
Here's an interesting picture of a Droopsnoot P-38 I found loaded with 3 x GP bombs (500 pounders?) on a single side and a drop tank (I think a 165 gallon Lockheed tank) on the other:
dropsnoot.jpg


And another with both sides loaded with bombs on a standard P-38:
5fNtxpA.jpg


I didn't know additional hard points were added in the center wing. Although this may be later in the war and most likely in Europe, I think it is interesting to consider the possibilities this could present for skip-bombing light targets.

Does anyone have any more information on when/where these multi-bomb setups were developed and first used?
 
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To the best of my knowledge, the 'triple rack' was a field mod. In Pacific, 82nd FG used this, they also experimented with out-board racks for 2x250 lbs bombs on each side.
 
To the best of my knowledge, the 'triple rack' was a field mod. In Pacific, 82nd FG used this, they also experimented with out-board racks for 2x250 lbs bombs on each side.
82nd FG? They were in the Med with the 1st and 14 FG (12th/15th AF).

I had heard about strapping 250#-ers to the OW hard points before.

Anyway, I found this G or H as well with four bombs and two tanks...although it appears these may be 250# (the diameter seems a little smaller than those of the previous which seems about right, AN-M57 250# had a body diameter of 10.9", AN-M64 500# had a body diameter of 14.2"):

500_800_Bomb.jpg

I think I may reserve more of these experiments for later in the war when the primary focus becomes Fighter-Bombing and CAS but maybe a limited deployment of the above is fitting for our immediate needs.
 
Droop snoots were weird looking birds...there was one at Ft Lauderdale airport back in the late 50's. And it had nothing to do with the used fighter plane lot up by the front entrance...
 
The droop snoots were supposed to be used as pathfinders for daylight accurate bombing raids for lighter strike aircraft instead of the light and heavy bombers. They were used to fool the defender's radar and defensive nets in Europe because the Nazis and Eu. collaborators were expecting real bombers than the Allied fighter sweeps. These fighters were created for the needs of the Romanian petrol raids.
 
Good luck! (For those folks outside the upper Midwest) We have a lot of snow on the ground all over and an extended stretch of warm weather for the region coming up. That meltwater has to go somewhere....

We here in Utah have been saying this winter is obviously very mad at us because she keeps leaving and then coming back and saying "And another thing..." Point of fact it snowed again today :)

Randy
 
Why did Kelly Johnson settle on a twin boom design?

sketch.png


Here are the design concepts that Kelly Johnson considered before choosing number 4 for the XP-38.
Most of the other layouts look questionable except for the design number 1 which worked out quite well for the DH Mosquito, Hornet, and similar aircraft. So why didn't Kelly Johnson use number 1?

Lockheed favoured twin tail designs as in the Electra and the Hudson. It's nice to have the propwash flowing over the rudders to enhance low speed control for take off and landing. But why have twin booms? Anybody know or would like to speculate?
 

marathag

Banned
It's nice to have the propwash flowing over the rudders to enhance low speed control for take off and landing. But why have twin booms? Anybody know or would like to speculate?

Two slim booms have less surface area than a larger central fuselage, less wetted area, less drag for the same interior volume.
 
Why did Kelly Johnson settle on a twin boom design?

sketch.png


Here are the design concepts that Kelly Johnson considered before choosing number 4 for the XP-38.
Most of the other layouts look questionable except for the design number 1 which worked out quite well for the DH Mosquito, Hornet, and similar aircraft. So why didn't Kelly Johnson use number 1?

Lockheed favoured twin tail designs as in the Electra and the Hudson. It's nice to have the propwash flowing over the rudders to enhance low speed control for take off and landing. But why have twin booms? Anybody know or would like to speculate?

Two slim booms have less surface area than a larger central fuselage, less wetted area, less drag for the same interior volume.

Johnson was probably running out of space, since he planned to use not just two engines, but also two turbo set-ups. Each half of aircraft requires oil cooing, coolant cooling, and intercooler, plus it houses one of main U/C, two fuel tanks initially, and radio(s). So with two coolant radiators per side, the rear part of nacelle grew so much that going for twin boom is not a wonder.

Bigger central fuslage will offer greater useful volume than two booms for the same wetted area, lower weight, lower price and less manufacturing time.
 
Johnson was probably running out of space, since he planned to use not just two engines, but also two turbo set-ups. Each half of aircraft requires oil cooing, coolant cooling, and intercooler, plus it houses one of main U/C, two fuel tanks initially, and radio(s). So with two coolant radiators per side, the rear part of nacelle grew so much that going for twin boom is not a wonder.

Bigger central fuslage will offer greater useful volume than two booms for the same wetted area, lower weight, lower price and less manufacturing time.


This is interesting. You're asserting the opposite of marathag that one central fuselage offers less wetted area for less drag. But finding room for all that equipment pushed Johnson toward a twin boom design. And I'm guessing that Lockheed wanted a twin tail anyway so that also weighted the decision. How much of a difference in surface drag between the two planforms? Maybe not so much but I'm uncertain.
 
Sounds reasonable about reducing the wetted area. I don't know why de Havilland didn't use the twin boom design.

A 'classic twin' makes much better sense for a bomber.
Hornet was initially suggested as trimmed-down Mosquito, basically a new, slim fuselage that uses tail and shortened wing from Mosquito.

This is interesting. You're asserting the opposite of marathag that one central fuselage offers less wetted area for less drag. But finding room for all that equipment pushed Johnson toward a twin boom design. And I'm guessing that Lockheed wanted a twin tail anyway so that also weighted the decision. How much of a difference in surface drag between the two planforms? Maybe not so much but I'm uncertain.

Let's look at a cylinder, that has r=2 ft and length, or height or 10 ft. Cross section is r^2xPi = 4x3.1416 = ~12.57 sq ft; circumference is 2rPi = 12.57 ft. We are interested in volume of cylinder (= 125.5 cu ft; the bigger the better) and area of the side of cylinder (125.7 sq ft; the lower the better since it will lower the drag).
Lets see how much of volume we get with two smaller cylinders that, added together, have same area of sides of cylinders; both cylinders are 10 ft long. One small cylinder has area of it's side = 62.85 sq ft. That gives the circumference of 6.285 ft, and radius of, well, 1 ft. Cross section is 1x1xPi = 3.1416 sq ft for one small cylinder, volume of 31.416 cu ft, or 62.832 cu ft volume for both cylinders.
At the end, the big cylinder as described (roughly describing a 'classic twin' rear fuselage) will offer twice the useful volume for same wetted area vs. two small cylinders (roughly describing 'twin boom').
 
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