Improve That Design: How Aircraft Could Have Been Made Better

[VA5124]

The SBD could already deliver 2,250 pounds to it's target. Why try and turbosupercharge it?

Dive bombers had to limit their speed in a dive (the SBD's limit was 250mph) so they could recover from the dive. One of the fastest divers was the Stuka at a duve speed of a little over 300mph.

Stuffing a monster engine in it won't change that.

thats the best way i can think to make it a better bomber

 

[GrauGeist]

thats the best way i can think to make it a better bomber

You can't fix perfection - the SBD broke the back of the Imperial Japanese Navy by sinking 4 fleet carriers and 2 light carriers, not to mention other warships.

 

[XBe02Drvr]

thats the best way i can think to make it a better bomber

You need to learn a little more about engines and aerodynamics.
The SBD already had a supercharger built right into its engine. In mechanic school we took a Wright R1820 (the engine the SBD used) apart, put it back together, and ran it. Adding a turbo to it won't give you more performance at the altitudes a WWII dive bomber operated at, only at higher altitudes where it has no need to go.
There's not much value in carrying multiple bombs, as the plane normally gets only one pass on a defended target. One 2,000 pound bomb is more effective against a hardened target than two 1,000 pounders.
There's a wealth of information in the various threads on this site. Read up.

 

[ThomasP]

Hey VA5124, check these out.

AM-1 Mauler
3x2000 lb torpedoes and 12x250 lb bombs, for a total of 9,000 lb payload

AD-1 Skyraider
3x2000 lb bombs, 6x500 lb bombs, and 6x250 lb bombs, for a total of 10,500 lb payload

 

[Shortround6]

And not a turbo in sight

 

[XBe02Drvr]

That's not what my infallible memory says, but I've got the book handy and will look it up tomorrow.

Guess I shouldn't trust my memory. According to the drawings on page 304 and 306 of P51B Mustang by our very own drgondog, the two stage Merlin supercharger has two coolers, an intercooler between stages, which is integral to the supercharger housing, and an aftercooler after the second stage, which is plumbed to a radiator adjacent to the glycol radiator in the belly scoop. The oil cooler is mounted in a separate duct in the belly scoop forward of and below the glycol/aftercooler radiator.
Thus it appears the belly scoop is handling nearly all of the powerplant cooling load and converting it to thrust. (When the belly scoop's rear exit auto-adjust scoop is working right!)

 

[Admiral Beez]

You can't fix perfection - the SBD broke the back of the Imperial Japanese Navy by sinking 4 fleet carriers and 2 light carriers, not to mention other warships.

Given the circumstances of thirty-one USN dive-bombers arriving at the ideal time, location and altitude with zero HA CAP to counter them and IJN CVs in disarray with vulnerable aircraft and unsecured fuel and bombs, I would argue that pretty much any dive bomber could have done the job. Replace those Dauntless with Vought SB2U Vindicator or Blackburn Skuas and the results should be about the same.

 

[pbehn]

Given the circumstances of thirty-one USN dive-bomber squadrons arriving at the ideal time, location and altitude with zero HA CAP to counter them and IJN CVs in disarray with vulnerable aircraft and unsecured fuel and bombs, I would argue that pretty much any dive bomber could have done the job. Replace those Dauntless with Vought SB2U Vindicator or Blackburn Skuas and the results should be about the same.

That is not how history works.

 

[GrauGeist]

Given the circumstances of thirty-one USN dive-bomber squadrons arriving at the ideal time, location and altitude with zero HA CAP to counter them and IJN CVs in disarray with vulnerable aircraft and unsecured fuel and bombs, I would argue that pretty much any dive bomber could have done the job. Replace those Dauntless with Vought SB2U Vindicator or Blackburn Skuas and the results should be about the same.

(just a head's-up: you might want to fix that "31 squadrons" thing)

The SBDs were diving at between 80 and 70 degrees in the Midway attack.
Any other dive-bomber (Stuka excluded) would have a higher chance of being spotted on it's approach due to a shallower dive angle.
That being said, the SBD sank two carriers that did have CAP as well as protected troop transports, Cruiser and so on.

The fact that all got through was due to the lack of CAP and they proceeded to overkill the carriers. It would have only taken several of them to do the job and the A6Ms, no matter how hard they tried, would not have been able to stop all of them.

 

[XBe02Drvr]

Given the circumstances of thirty-one USN dive-bomber squadrons arriving at the ideal time, location and altitude with zero HA CAP to counter them

Huh? Where did you come up with thirty-one squadrons of SBDs?? Each carrier had two SBD squadrons, a bombing (VB) and a scouting (VS), which was also a trained dive bombing squadron. Hornet's two SBD squadrons never made the scene, but one from Midway did. The Midway squadron were rookies, new to dive bombing and new to the aircraft, with predictable results. Adds up to five squadrons in my book.
They were fortunate in that the CAP, while fairly strong at 42, was scattered and distracted (not all at low altitude, as common mythology asserts), but the scattered-to-broken cloud deck and the Japanese lack of effective radar obscured their approach. Given equally competent crews, Vindicators or Skuas, with their slower speeds and lighter payloads would likely have been hard put to match that performance.

 

[SaparotRob]

Perhaps 31 SBD's? I don't recall the exact number of Dauntless's but I'm sure the Admiral didn't mean squadrons.

 

[GrauGeist]

The problem with the Midway based SBDs and SB2Us during the battle, is that they did not follow their training and attack from a high altitude, instead attacking from a much lower elevation.
This not only alerted the Japanese to their presence, but allowed the CAP to interdict before getting into position.

 

[SaparotRob]

It may have been lack of training. I recall reading that the Midway based SBD's were new pilots and their CO (It's bugging me that I can't remember his name) did a glide bombing attack due to their inexperience. I'm going to have to do some reading.

 

[Zipper730]

I'm sure it flew in a test bed before it made its way into the XB-19A.

It was merely the first aircraft that I knew it flew on, though I'm not sure the exact timeframe.

If needs must, that factory could have been converted to production of the V-1710 and V-3420.

That's good to know. Honestly, I'm curious to know how hard it would have been for US Army to have simply changed the hyper-engine from single to monoblock construction?

The original scheme was for the X-3420, which was an X engine, using four V-1710 cylinder banks and heads on a crankcase that had a single crankshaft. Each bank had 6 cylinders. The angles between the banks were not 90° like the Vulture, but I can't recall what the angle were.

The X-3420 was also to be direct injected, as was the goal at the time for the V-1710 as well.

What advantages come with direct injection vs. the pressure carburetor?

It may have been due to a change in personnel that saw Allison counter-propose the V-3420. The reasoning was that using twin crankshafts, and 60° between two banks either side there were more components that could be carried over from the V-1710. It was also though that more power would be available, due to stronger crankshafts and connection rods - which would be the master and slave type for the X-3420.

I'm guessing having an X-cylinder with 2-sets of 60-degrees between them top and bottom would be more difficult to pull off? What's a master and slave type rod, and what would make it weaker than the twin-crankshafts of the X-3420?

The V-3420 was expected to be cheaper and easier to build, and be available for production sooner, due to the higher number of shared components.

How much earlier would you have guessed?

 

[GrauGeist]

It may have been lack of training. I recall reading that the Midway based SBD's were new pilots and their CO (It's bugging me that I can't remember his name) did a glide bombing attack due to their inexperience. I'm going to have to some reading.

Maj. Henderson USMC (Henderson field was named in his honor)

 

[Zipper730]

The SBD already had a supercharger built right into its engine.

Yeah, almost all WWII engines had an integral supercharger built into them.

Adding a turbo to it won't give you more performance at the altitudes a WWII dive bomber operated at, only at higher altitudes where it has no need to go.

I'd stipulate to the argument that, later in the war, with proposed single-engined dive-bomber/attack aircraft (like the XA-41), that an improved supercharger would have been useful since the fighters were now able to go higher, the attack planes should be able to cruise higher too, as it'd give them better performance.

There's not much value in carrying multiple bombs, as the plane normally gets only one pass on a defended target. One 2,000 pound bomb is more effective against a hardened target than two 1,000 pounders.

Generally speaking, land-based dive-bombers usually tended to have multiple smaller bombs (ranging from about 110-500 lb. typically), whereas naval dive-bombers usually were built around carrying larger bombs (500 lb. to 1600 lb., maybe 2000 lb.) because land-based dive-bombers would probably be aiming at things like tanks, pill-boxes, and people (with the occasional bridge). People are, for better or worse, soft and squishy and, while tanks are armored, they seem easier to destroy than ships.

I have no idea how sturdy a typical pillbox or a bridge of WWII vintage was.

 

[SaparotRob]

Maj. Henderson USMC (Henderson field was named in his honor)

And that's why it was bugging me. Senility sucks.

 

[Admiral Beez]

Huh? Where did you come up with thirty-one squadrons of SBDs??

That's your contribution?

(just a head's-up: you might want to fix that "31 squadrons" thing)

The SBDs were diving at between 80 and 70 degrees in the Midway attack.
Any other dive-bomber (Stuka excluded) would have a higher chance of being spotted on it's approach due to a shallower dive angle.
That being said, the SBD sank two carriers that did have CAP as well as protected troop transports, Cruiser and so on.

The fact that all got through was due to the lack of CAP and they proceeded to overkill the carriers. It would have only taken several of them to do the job and the A6Ms, no matter how hard they tried, would not have been able to stop all of them.

Thanks Grau. I had started as three squadrons but edited to the number of aircraft instead.

 

[pbehn]

That's your contribution?
.

Obviously not, you edited out the rest of his contribution? Here it is, " Each carrier had two SBD squadrons, a bombing (VB) and a scouting (VS), which was also a trained dive bombing squadron. Hornet's two SBD squadrons never made the scene, but one from Midway did. The Midway squadron were rookies, new to dive bombing and new to the aircraft, with predictable results. Adds up to five squadrons in my book.
They were fortunate in that the CAP, while fairly strong at 42, was scattered and distracted (not all at low altitude, as common mythology asserts), but the scattered-to-broken cloud deck and the Japanese lack of effective radar obscured their approach. Given equally competent crews, Vindicators or Skuas, with their slower speeds and lighter payloads would likely have been hard put to match that performance. " Though I dont see how this type of discussion moves anything on.

 

[GrauGeist]

And an interesting side-note regarding the Battle of Midway:
The SBD pilots were using the Hinomaru painted on the Carriers' deck as their primary aim-point.
Shortly after the battle, the IJN removed it from their other carriers.