# TBF Avenger obsolete in light of SBD Dauntless SB2C Helldiver?



## gjs238 (Mar 7, 2015)

Would Grumman's resources have been better spent designing and manufacturing the replacement for the SBD Dauntless?

Curtiss did not handle the SB2C Helldiver project well.
Grumman began development of the Avenger two years later that Curtiss began the Helldiver, yet the Avenger entered service sooner.

And divebombers, at least in US service, had eclipsed torpedo bombers.


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## Capt. Vick (Mar 7, 2015)

In hindsight yes, but when the Avenger was ordered torpedo bombing was still very much thought to be a viable form of attack. Perhaps even over dive bombing as the prevailing US Navy aviation saying "Want to damage a ship bomb it, want to sink a ship torpedo it" as I remember reading in "First Team".

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## pbehn (Mar 7, 2015)

Capt. Vick said:


> In hindsight yes, but when the Avenger was ordered torpedo bombing was still very much thought to be a viable form of attack. Perhaps even over dive bombing as the prevailing US Navy aviation saying "Want to damage a ship bomb it, want to sink a ship torpedo it" as I remember reading in "First Team".



Having torpedoes that explode is a big help.

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## tyrodtom (Mar 7, 2015)

pbehn said:


> Having torpedoes that explode is a big help.



I know the torpedoes used by the US Navy's subs were pretty much junk early WW2.
The aircraft dropped different torpedoes didn't they ?

Were they problematic too ?


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## GrauGeist (Mar 7, 2015)

The Mark 13 was designed specifically for aircraft and was actually a good performer, unlike the ship-born Mark 14 and Mark 15 types.

Might also be interesting to know that PT boats used the Mark 13 type, too.


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## RCAFson (Mar 7, 2015)

GrauGeist said:


> The Mark 13 was designed specifically for aircraft and was actually a good performer, unlike the ship-born Mark 14 and Mark 15 types.
> 
> Might also be interesting to know that PT boats used the Mark 13 type, too.



The Mk 13 had more than it's share of problems too:



> a total of 156 Mark 13 Mod 0 torpedoes were produced which was enough to provide two loads for each of the four 18-plane torpedo squadrons assigned to the pre-war carrier fleet plus a dozen spares. Mod 0 differed from later mods by having a rail-type tail in which the propellers were in front of the rudders. This was the only US torpedo to ever have this feature. The Newport Torpedo Station was unhappy with arrangement for reasons unknown and the Mod 1 entered service in 1940 with a conventional propeller arrangement, as can be seen in the photographs above. Unfortunately and unlike the Mod 0, the Mod 1 proved to be an unreliable weapon, with only one of ten torpedoes dropped by VT-6 during an exercise in July 1941 having a hot, straight and normal run. Of the others, four sank and could not be recovered while the other five experienced erratic runs.
> 
> These problems continued into the early war years, with a mid-1943 analysis of 105 torpedoes dropped at speeds in excess of 150 knots found that 36 percent ran cold (did not start), 20 percent sank, 20 percent had poor deflection performance, 18 percent gave unsatisfactory depth performance, 2 percent ran on the surface and only 31 percent gave a satisfactory run. The total exceeds 100 percent as many torpedoes had more than one defect. The early models were further handicapped by the need to drop them low and slow - typically 50 feet (15 m) and 110 knots - which made the torpedo planes carrying them vulnerable to attack.
> 
> ...


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## RCAFson (Mar 7, 2015)

gjs238 said:


> Would Grumman's resources have been better spent designing and manufacturing the replacement for the SBD Dauntless?
> 
> Curtiss did not handle the SB2C Helldiver project well.
> Grumman began development of the Avenger two years later that Curtiss began the Helldiver, yet the Avenger entered service sooner.
> ...



The TBF was a much easier plane to design, as it did not have to (and could not) cope with the stresses involved in divebombing and the problems involved in designing a successful dive brake.

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## GregP (Mar 8, 2015)

I see the Helldiver maligned all the time verywhere on the internet and in museums.

Yet despite this, it came into servce later than the TBF/TBM and the SDB, flew half the action sorties of the TBM/TBF, had similar losses, had less than half of the losses to enemy aircraft, and delivered about 1/3 of the tonnage of bombs on target the TBF did. The kill to loss ratio was better than the TBF/TBD.

The data come from Table 2 of Opnav -P-23V, dated 17 Jun 1946, Consolidated Summary of Navy and MarineAir Operations and Results for Entire War.

Since it arrived late, it seems to me the actual record indicates the SB2C was a pretty decent aircraft in the end.


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## GrauGeist (Mar 8, 2015)

The Mark 13 did have it's problems, but by and large, the Mark 13 out performed it's vessel-launched counterparts by quite a margin.


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## tomo pauk (Mar 8, 2015)

Compared with other US torpedoes, it did not have problems with pistols/detonators. But it was darn slow, from 30 kts in beginning, ending up at 33.5 kts. The Japanese air-launched types were good for 41-43 kts, British types were at 40 kts, the Italian F200 was also at 40 kts; reliability was greater than of Mk 13.
The launch envelope was severely restricted until the 'pickle barrell' was not attached to the nose, later the trip wire was used to further improve launching height and speed.

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## Timppa (Mar 8, 2015)

With 20/20 hindsight, Grumman could have developed a smaller Skyraider around R-2800 engine, a capable dive/torpedo bomber.

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## Shortround6 (Mar 8, 2015)

The trouble with hindsight is that does not take into account the situation the US Navy was in 1939. 

They knew the Devastator, no matter how ground breaking in 1935, was thoroughly obsolete even in 1939 let alone going forward into 1941/42 which is why they were spec-ing a new airplane. The R-2600 was a production engine (although low in numbers, 163 built in 1939) while the first R-2800 to fly (in a test mule aircraft) only did so in the summer of 1939. 
Waiting for a better plane powered by the R-2800 may not have been a luxury they could afford. Considering the total hash Curtiss made of the SB2C waiting and depending on 'rush' programs is not really a good plan. Curtiss started before Grumman, it was a much larger, more experienced company than Grumman and yet still _managed_ to come up with a totally unsuitable/unusable _initial_ design/prototype. Despite starting well over a year earlier (some say two years) it made it's combat debut well over year after the Avenger. 
In 1939-41 the idea that a torpedo bomber or dive bomber could survive without a rear gunner was a totally unproven concept. Also remember that the torpedo and dive bombers in US service had a secondary role as recon aircraft (scouts). The US Navy having no dedicated recon carrier aircraft or preferring to use bomber types as scouts and use single seat fighters rather than build 2 seat fighter/recon planes (Fulmar?). 
The Helldiver entered a rather different combat situation than the Avenger. With first combat use in Nov of 1943 it did pile up a good statistical record of bombs dropped and low losses but then it was being escorted (mostly) by Hellcats and Corsairs and not Wildcats. The quality of the Japanese opposition in 1944 may not have been what it was in 1943 either. 
That is part of the problem with suggesting single seat attack (dive bomber/torpedo bomber) aircraft for _early_ war use. There was an entire generation of Navy attack aircraft _between_ the Avenger/Helldiver and the Skyraider. Few, if any, made it past the prototype stage, at least in original condition. They often had such features as top and bottom gun turrets (some were remote controlled) and interior bomb bays. They quickly became too big (even on the drawing board) for even R-3350 engines and the vast number of small carriers the Navy wound up with. Planing aircraft for 45,000ton carriers and getting 11,000ton carriers instead will change aircraft requirements. Changes in doctrine (like number of fighter squadrons per carrier) and using smaller carriers to carry extra fighters (not all carriers carried the same "mix" of aircraft) meant that the weight/bulk of the defensive armament could be done away with and defense handed off to the fighter escort. 

Avengers could be used on smaller carriers than the Helldiver and with F6Fs and F4Us being used as dive bombers in 1944 the small carriers could carry just two types of aircraft and still under take a variety of missions. 

BTW, this was ordered 9 months before the Skyraider.





To show what the Navy was thinking at the time.


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## Capt. Vick (Mar 8, 2015)

Love the skypirate!


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## tomo pauk (Mar 8, 2015)

Wonder whether the Avenger with dive brakes would be at least half good a dive bomber?


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## Shortround6 (Mar 8, 2015)

Probably not stressed for the HIGH "G" pull out. 

http://www.ww2aircraft.net/forum/aviation/structure-weight-data-drag-analysis-42716.html

Second page. G Factor for the Tarpon (Avenger) not given but Barracuda was 9, Spitfire IX was 10.0, Vultee Vengence was 13.5. 

How steep do you want to dive and how hard do you want to pull out (and how many times, lots of airplanes might do it 2-3 times, doing a dive bomber pull out in a plane that has done 30-40 (training) and has 3-400hours and 50-80 carrier landings on the airframe??)


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## RCAFson (Mar 8, 2015)

Shortround6 said:


> Probably not stressed for the HIGH "G" pull out.
> 
> http://www.ww2aircraft.net/forum/aviation/structure-weight-data-drag-analysis-42716.html
> 
> ...



According to the TBF 1C manual, max g load at 15000/16000lb was +3.8/+3.4 and -2/-2


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## Shortround6 (Mar 9, 2015)

Thank you.


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## Timppa (Mar 9, 2015)

Shortround6 said:


> The trouble with hindsight is that does not take into account the
> situation the US Navy was in 1939.




You have better understanding of English than I have, but I understand that hindsight means: 
Recognition of the realities, possibilities, or requirements of a situation, event, decision etc., after its occurrence.

So I take it that you know exactly the situation in 1939 and afterwards.

The combat debut for the Avenger (R-2600) was at Midway
The combat debut for the B-26 (R-2800) was at Midway.



> Waiting for a better plane powered by the R-2800 may not have been a luxury they could afford.


With hindsight, they could.



> In 1939-41 the idea that a torpedo bomber or dive bomber could survive without a rear gunner was a totally unproven concept.


With hindsight, they could and did survive (Thach weave etc.)



> BTW, this was ordered 9 months before the Skyraider.



There was nothing crucial in the Skyraider, that could not have engineered in 1938-1940. Heinemann specifically simplified - according to his KISS principle - the previous bloated designs : No gun turrets, no nose landing wheel, no contra-rotating props, simple fuel system, no bomb bay.

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## Shortround6 (Mar 9, 2015)

I may not "Know exactly the situation in 1939 and afterwards" but a single seat attack plane using an 1850hp engine (same as the early B-26 engine) isn't going to give that much better performance than the 1700hp R-2600. Especially considering the R-2800 weighed about 300lbs more and would need a bigger prop. Granted you are getting rid of two crewmen and a fat fuselage. 
We KNOW with _hindsight_ that the Avenger worked, we also know the Helldiver took years to straighten out. 
We also know it took Vought until 22 December 1941 to fly the XTBU-1 Sea Wolf with an R-2800 engine. 






We know that Brewster failed to make a decent dive bomber with the SB2A Buccaneer (R-2600 engine).
I don't know if the Brewster SB2A was also entered in the design competition with the Avenger or how different the torpedo bomber version was. 
It was the Navy that Specified that the torpedo/bomb load had to carried inside an enclosed bomb bay, not the designers. By the end of the war some designers might have built up enough reputation to propose alternatives to army or navy specified features but that was doubtful at the beginning of the war. 

The Avenger turned out to be the best and quickest program of the Navy strike aircraft (1 for 4) but claiming it could be delayed even a few months might not have been a good idea. 

While there were only 6 Avengers at Midway by August ALL operational carriers in the Pacific carried a full compliment of Avengers for their torpedo squadrons. 

The Thach weave was used by fighter elements. I am not so sure how it would have worked for torpedo bombers. Granted the defensive guns didn't work all that well either but pairs of torpedo bombers weaving back and forth at torpedo bomber speeds and with light forward firing armament are going to have a hard time taking out attacking fighters.


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## GrauGeist (Mar 9, 2015)

Shortround6 said:


> ...The Thach weave was used by fighter elements. *I am not so sure how it would have worked for torpedo bombers.* Granted the defensive guns didn't work all that well either but pairs of torpedo bombers weaving back and forth at torpedo bomber speeds and with light forward firing armament are going to have a hard time taking out attacking fighters.


If anything, employing the "Weave" would slow them down even more...


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## gjs238 (Mar 9, 2015)

The F6F was supposed to be powered by a R-2600 but was switched to the R-2800.
With hindsight, so could have the Avenger.


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## gjs238 (Mar 9, 2015)

Still, with hindsight, the Skyraider philosophy could have/probably would have been more successful. Albeit powered via R-2600 or R-2800.


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## Shortround6 (Mar 9, 2015)

Kind of leaves you short a plane for all the other roles the Avenger did though 

Other thread on bombers is interesting. R-3350 was good for 2200hp on take-off and 2000hp max continuous in WW II. The engine used in the first Skyraiders was good for 2500hp take-off and a max continuous rating of 2100hp, later Skyraiders got even more powerful engines. 2700hp for take-off and 2300hp max continuous. Engines used in early B-26s were good for 1850hp take off and 1500hp at 7500ft max continuous. We have either a very under-powered Skyraider or a 3/4-2/3rds Skyraider. What do you want to give up, speed? Load? range? some of all three?


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## gjs238 (Mar 9, 2015)

I guess it's semantics, but rather than an under-powered Skyraider lets get a more effective Avenger.


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## tomo pauk (Mar 9, 2015)

The 'Skyrider minus' comes out short when it is about to use and on-board radar set.

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## Shortround6 (Mar 9, 2015)

gjs238 said:


> I guess it's semantics, but rather than an under-powered Skyraider lets get a more effective Avenger.



effective how?

Avenger held 335 US gallons in internal tanks. Early Skyraider 325? Carrying ordnance externally has more drag (shorter range) than internal stowage. With more power you can lift drop tanks in addition to weapons but that doesn't change actual strike radius that much if you are burning some of the extra fuel to fight the drag of the drop tanks and external ordnance. A 1942/43 Skyraider is going to carry four .50s or two 20mm cannon at best. If it is carrying more guns it isn't doing it's job of carrying bombs/torpedo. More likely is a pair of .50 cal guns on the 1850hp model. 
Avenger had a bigger wing than the Skyraider. Helped keep take-off and landing speeds down and allowed operations of both the USS Independence class carriers and the smaller CVEs. Of course both those classes were not thought of when the initial specification was written. 
Avengers often did "armed reconnaissance" A couple of 500lb bombs in the bomb bay while a small group of planes (2 or 4?) performed searches. Avenger has three sets of eyes as search gear early in the war. Skyraider minus has one pair? 
Single seat Skyraider minus will be a better ASW aircraft?


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## GregP (Mar 10, 2015)

If they went with an R-2800 for the Shyraider, it would need to scaled down for teh power to weight ratio accordingly. I don't see taht as a quick thing and would eeject a full-size Skyraider with an R-2800.

But ... the Kaiser-Fleetwings XBTK might have proven useful in the extreme.


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## Shortround6 (Mar 10, 2015)

The Fleetwings XBTK might have been very useful. 
It also used the same engine as the F8F Bearcat. A 1942 version with 1850hp for take-off instead of 2100hp ( and 2300-3400 with water injection) might not have been quite as useful. The later engine also picked up 200hp at max continuous setting.
Did a Plane that _started_ design in Jan 1944 use any different aerodynamics (airfoil, cowl, etc) than a 1939-40 aircraft? 
Did a Plane that _started_ design in Jan 1944 use any different knowledge of structure/s than a 1939-40 aircraft?

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## tomo pauk (Mar 10, 2015)

The 1942 version should have had 2000 HP for take off, at least by Midway.

Re. adrodynamics - Grumman, for example, stood with NACA 230 series of profiles during all of ww2. An earlier adoption of Fowler flaps might've helped.


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## Shortround6 (Mar 10, 2015)

tomo pauk said:


> The 1942 version should have had 2000 HP for take off, at least by Midway.



Maybe. The 2000hp engines don't start to make it to the engine factory loading docks until Jan 1942.(aside form a 1/2 dozen or so). Now you have to get them to the airframe factory. Get them installed in the airframes. Test fly the plane. Prepare the plane for shipment, load it on a ship and get it to Hawaii (and if an east coast Manufacturer you have send the ship by way of the Panama Canal.) Unload it, un-crate or un-cocoon it and prep for flight and test fly. 

They had six Avengers at Midway and they started rolling Avengers out the door in Dec 1941. Maybe not the full six  and granted they had dozens more by August. The engines for those Avengers may have left Paterson NJ in Nov/Dec of 41. 

A lot of people underestimate how long it took for a lot of American war material to reach combat theaters.

It is about 4950 miles (7980km ?)direct route by air from Paterson to Hawaii, by ship?????

Found cool site 

Sea route distance - ports.com

it is 7428NM for New York to Pearl harbor and 30.9 days on a 10 Knot ship.


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## gjs238 (Mar 10, 2015)

Shortround6 said:


> The Fleetwings XBTK might have been very useful.
> It also used the same engine as the F8F Bearcat. A 1942 version with 1850hp for take-off instead of 2100hp ( and 2300-3400 with water injection) might not have been quite as useful. The later engine also picked up 200hp at max continuous setting.
> Did a Plane that _started_ design in Jan 1944 use any different aerodynamics (airfoil, cowl, etc) than a 1939-40 aircraft?
> Did a Plane that _started_ design in Jan 1944 use any different knowledge of structure/s than a 1939-40 aircraft?



This is more like what I had in mind!
(but much earlier)


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## Shortround6 (Mar 10, 2015)

A lot depends on the Navy requirement and how much they were were willing to bend.

Initial specification for the Avenger gave speed (over 300mph), landing speed _with_ torpedo (one reason for that big wing), Service ceiling of 30,000ft ( why has never been explained) length of fuselage to fit existing carrier lifts. Range with load and so on and so on. 

Without hind sight they didn't know how much of problem the MK 13 Torpedo had which lead to the Avengers carrying bombs. However that ridicules drop speed should have been a red flag by 1939. 

Once you stick a bomb bay capable of holding a MK 13 torpedo in a plane, making it (the bay) a little longer and putting in a rear lower gunner station isn't so bad. AN avenger had more wing area than an A-20, Sticking another 150hp into that fat fuselage and with that big wing wasn't going to give you enough speed to matter over the 1700hp engine. 

Trouble is if you hang the torpedo (and more especially four 500lb bombs) out in the open with all the drag, will even a skinnier fuselage and smaller wing give you the _range/radius_ you need? The Navy wanted a bench mark range of over 1000 miles _with_ ordnance. Not with drop tanks. The _ideal_ was to be able to hit the enemy fleet (carriers) at a longer range than he could hit you from. It didn't wind up working that way but.......

There are a lot of trade offs with older carrier planes and just because a certain type of aircraft could do a few certain, selected missions better than a different type of aircraft doesn't mean it would have been a better overall choice considering all missions.


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## gjs238 (Mar 10, 2015)

I thought that with later torpedo and/or bombers the USN abandoned the concept of the internal bomb bay?


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## Shortround6 (Mar 10, 2015)

They did but we are backwards projecting. They were also using brute force (engines over 2000hp) to get the range they wanted. And the range didn't increase much. 

Figures for the TBF-1/TBM-3 vary a bit but the planes topped out at just over 270mph, they would 'cruise' at 145/163 and could carry a torpedo 1215/1065miles. The TBM-3 use a 1900hp R-2600. 
The Fleetwings topped out at 373mph but speed _with_ torpedo is is given as 258-297. Cruise is given as 158mph and range with torpedo as 1250 miles. 
The Prototype Skyraider topped out at 375 but with torpedo 303mph is given, cruise 185mph and range with torpedo 1427miles. 

No mention of drop tanks is made one way or the other. 

BTW the Boeing XF8F had an internal bay that would hold four 500lb bombs (?)




so internal vs external was still a bit open. 

Here is picture of the Fleetwings with large bomb, radar pod (?) and drop tank.


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## Conslaw (Mar 10, 2015)

The Avenger was a very effective naval attack plane in World War II. It was not a great torpedo bomber because of deficiencies in American torpedoes combined with the fact that the role was gradually rendered obsolete by increased effectiveness of anti-aircraft guns. As it turned out, the Avenger became crucial to the US Navy and Royal Navy as a place to put its stuff. With the Avenger, they had a plane that could carry radar and a radar operator. It could carry sonar buoys and fido Mk 24 anti-submarine torpedoes, depth charges, rockets, extra gas tanks for overnight patrols, It could seat 6 and still land on an aircraft carrier when outfitted for carrier on-board delivery. It could carry 2,000 lb bombs. It could carry napalm. It could carry searchlights and magnetic anomaly detectors. Late in the war, they even experimented with the Avenger in electronic countermeasures and distant early warning. The Avenger may have been the successor to the TBD, but it was the predecessor to all of the anti-submarine and all the specialty aircraft that have succeeded it on American carriers.

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## Shortround6 (Mar 10, 2015)

The trouble with focusing on the attack mission in the original posting is that it ignores all the other missions the the Avenger wound up doing, _mostly_ unintended to start with it is true. Although the 'scout' mission was not. 
A better bet would would have to come up with a back up to the Helldiver. Unfortunately, historically, the Navy thought they had that covered with the Brewster Buccaneer. The cure turned out to be worse than the disease.

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## gjs238 (Mar 10, 2015)

Conslaw said:


> The Avenger was a very effective naval attack plane in World War II. It was not a great torpedo bomber because of deficiencies in American torpedoes combined with the fact that the role was gradually rendered obsolete by increased effectiveness of anti-aircraft guns. As it turned out, the Avenger became crucial to the US Navy and Royal Navy as a place to put its stuff. With the Avenger, they had a plane that could carry radar and a radar operator. It could carry sonar buoys and fido Mk 24 anti-submarine torpedoes, depth charges, rockets, extra gas tanks for overnight patrols, It could seat 6 and still land on an aircraft carrier when outfitted for carrier on-board delivery. It could carry 2,000 lb bombs. It could carry napalm. It could carry searchlights and magnetic anomaly detectors. Late in the war, they even experimented with the Avenger in electronic countermeasures and distant early warning. The Avenger may have been the successor to the TBD, but it was the predecessor to all of the anti-submarine and all the specialty aircraft that have succeeded it on American carriers.



How many of those "other" tasks/missions you listed by performed by the SB2C Helldiver?
(Not arguing for/against either aircraft, just curious)


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## pbehn (Mar 10, 2015)

Werent torpedoes used less and less in part because Japan had only a limited number of ships that can be attacked by torpedo, more and more missions being in support of landings etc?


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## gjs238 (Mar 10, 2015)

pbehn said:


> Werent torpedoes used less and less in part because Japan had only a limited number of ships that can be attacked by torpedo, more and more missions being in support of landings etc?



Thought the (US) low, steady and slow torpedo bombers almost always got shellacked - the dive bombers got better results, so that's where the effort went.


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## Shortround6 (Mar 10, 2015)

pbehn said:


> Werent torpedoes used less and less in part because Japan had only a limited number of ships that can be attacked by torpedo, more and more missions being in support of landings etc?



It's kind of a chicken and egg thing. 

They found out the torpedoes weren't working well and tried different bombing tactics. Level bombing didn't work well either. Glide (shallow dive) and skip bombing worked better but Avengers were a bit more vulnerable to AA fire (due to speed of approach). By the time the torpedoes were straightened out and modified for higher speed/higher altitude dropping a fair number of Japanese ships had been sunk. 

Of course you still needed torpedoes for the big ships. Accounts of the sinking of Musashi describe up to 22 torpedo hits. (over claiming?) 

Yamato was hit by 11-13 torpedoes. 500 and 1000lb bombs can certainly damage the topsides and put even large turrets out of action but they needed torpedoes for the actual sinking. 

The difference in results between skip bombing and torpedoing a 3-5000 ton freighter are going to rather small. It is going to sink, just how fast. 

And please remember that while the MK number of the torpedo stayed the same there were a number of mods, some minor and some major that greatly changed the drop envelope (speed and altitude of the aircraft).


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## GregP (Mar 10, 2015)

If a 1944 aircraft didn't use different aerodynamics than a 1939 - 1940 aircraft, then the designer must have been asleep for 4 or 5 years. Aerodynamics went from 350 mph airplane to 450 mph airplanes in that timeframe.


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## kool kitty89 (Mar 11, 2015)

GregP said:


> If a 1944 aircraft didn;t use different aerodynamics than a 1939 - 1940 aircraft, then the designer must have been asleep for 4 or 5 years. Aerodynamics went from 350 mph airplane to 450 mph airplanes in that timeframe.


There's still some question of how much that would impact aircraft in the <300 MPH flight envelope. British carrier based bomber developments stayed slow up to the end of the war ... very slow compared to American Bomber/Torpedo/Attack aircraft. And even the american bombers/attackers were hardly getting into the mid 300 mph range. (granted, it's the emphasis on fighter-bombers that was the bigger issue there)


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## GregP (Mar 11, 2015)

Well, the P-47 is certainly classed as a fighter-bomber and was well into the mid to upper 400 mph range. The P-47N at the end of the war made 470 mph at best altitude ... granted without any bombs aboard (or even bomb racks), but it certainly wasn't exactly slow. I don't consider the Typhoon slow either ... and it was a one hell of a fighter-bomber.


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## Shortround6 (Mar 11, 2015)

I may be mis-using the word aerodynamics in this case but I am using it to cover not just airfoils and different flaps but just about anything concerning airflow. Like better radiators and radiator ducts, better oil coolers/ducts, better radial engine cowlings, even better canopy designs or wing root fairings. 
While lower drag shows up in faster speeds for the same power it also means longer range at cruising powers. 
And for the R-2800 advocates, the "C" series engines (P-47M/N, F4U-4, Fleetwings, Bearcats, Tigercats, etc) the change in the cooling fins meant less airflow was needed through the cowl for the _same_ power levels. The Better cooling also meant that the "C" engines could be run about 10% leaner at the higher power Settings (high speed cruise). Not a huge change in itself but again it points out trying to compare a 1944/45 aircraft to a 1941/42 aircraft is going to have some problems. The "C" series engines are not just more powerful when pushed to higher limits but more economical when run at lower limits. There may not be a lot to chose when you get down to cruise speeds of 180mph though.

This difference in cooling also meant that they could make _more_ power for the _same_ drag as the older engine which certainly didn't hurt top speed performance.

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## Shortround6 (Mar 11, 2015)

gjs238 said:


> How many of those "other" tasks/missions you listed by performed by the SB2C Helldiver?
> (Not arguing for/against either aircraft, just curious)



The Helldiver could do _some_ of the jobs. Helldiver had some low speed handling issues and a higher stall speed than the Avenger which prevented or restricted it's use on smaller carriers. Avengers could operated (although at restricted weights) off of even the smallest/slowest carriers. 
A number of sources claim the Helldiver could carry a torpedo but photos of a torpedo on/in a Helldiver are rare. Photos with torpedoes _near_ a Helldiver are easy to find. Some accounts say ONE plane was tested for several months and that the Torpedo was mounted outside the bomb bay (I have seen a photo of this) and it took several hours to convert the plane.


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## RCAFson (Mar 11, 2015)

Shortround6 said:


> The Helldiver could do _some_ of the jobs. Helldiver had some low speed handling issues and a higher stall speed than the Avenger which prevented or restricted it's use on smaller carriers. Avengers could operated (although at restricted weights) off of even the smallest/slowest carriers.
> A number of sources claim the Helldiver could carry a torpedo but photos of a torpedo on/in a Helldiver are rare. Photos with torpedoes _near_ a Helldiver are easy to find. Some accounts say ONE plane was tested for several months and that the Torpedo was mounted outside the bomb bay (I have seen a photo of this) and it took several hours to convert the plane.



Apparently the early SB2C variants took a considerable amount to time to convert to torpedo bombers, however late in the war a quick conversion kit was supplied that reduced the time and effort considerably, so much so that there were calls to remove the TBF/TBM from fleet carriers and use the SB2C-4/5 exclusively and if the war had lasted longer the Midway class would have gone to war with only the SB2C and fighter aircraft. 

The SB2C carried the Mk13 partially externally in similar fashion to the TBD and this reduced range and performance somewhat. OTOH, the SB2C was stressed for divebombing and thus it could use RN FAA style attack profiles with a very steep dive to release height, which would minimize exposure to flak.


> ...having to remove the bomb displacement gear forward arms'... from a very inaccessible location', and then having to fit the forward arms of the torpedo mounting assembly. Finally, all the actual loading tests were made with the torpedo fairing completely removed, and then no difficulty was found. The conclusions were that a complete redesign of the torpedo mounting assembly was essential, and methods to achieve this were detailed.
> 
> This was eventually done to complete satisfaction. However, the Helldiver was never used as a torpedo dropper in combat despite the fact that Admiral Halsey wanted to take the combining of the dive- and torpedo-bomber functions of his carrier aircraft much further some time later in the war. In November 1944 he proposed the total removal of the Grumman TBM Avenger, a most successful torpedo and glide bomber, from his fast carriers, proposeing instead to rely entirely on Helldivers for torpedo attack. This idea had its advocates and its opponents amongst his carrier captains at this time: Captain C. D. Glover of the Enterprise was all for it, as was Captain W. W. Litch of the Lexington. However, in the short term the chief of naval operations strongly disagreed, and the idea was not taken further:
> 
> ...


 Smith, Curtiss SB2C Helldiver, p57.


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## Shortround6 (Mar 11, 2015)

Well, that is great for the "fast" carriers. However you still need Avengers for the Independence class and and dozens of CVE carriers so stopping production of Avenger early in the war would have left more than few holes in aircraft deployment. 
Avenger variants filled a large number of roles late in the war and post war that were not even a thought off pre-war or early war. Trying to fill these roles without the Avenger would have lead to a mad scrabble. 







This variant was flying in 1944 even though the Production versions didn't see combat in 1945, they were still in training. 
It was used for both Airborne Early Warning and for anti-sub work (it needed another plane to carry the weapons.) 
They were operated of the small CVEs for a while post war. 

We know with hindsight that the US Navy had trouble with their torpedoes during the early part of the war and that the Helldiver sucked big time (not available) for 1942 and most of 1943 so a more effective dive bomber than the 1000-1200hp Dauntless certainly looks attractive as a weapon during those years. 
However with hindsight we know how useful the Avenger turned out to be in other roles and the lack of the Avenger airframe would have hurt Naval Aviation. With _Hindsight_ one is also left wondering why it took so long to fix the MK 13 torpedo. 
I mean you are ordering a new plane that is 100mph faster than the Devastator and even the Devastator _had to slow down_ to drop the torpedo and it took them 3 years to figure out that it might be better to be able to drop the torpedo faster and higher?

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## oldcrowcv63 (Mar 11, 2015)

tomo pauk said:


> The 'Skyrider minus' comes out short when it is about *to use and on-board radar set*.





To me this is a critical consideration in this discussion. I probably don't need to provide a detailed account the TBF's illustrious history to contributors here, so I'll just summarize some high points as possible reminders:

The Venerable TBF soldiered on into the 1950's remaining in US operational use as well as that of other nation's naval and even land-based air arms including those of Britain, Canada, and New Zealand (and others). It's ample payload and roomy crew accommodations facilitated its pioneering application to a variety of roles that required the installation of new and necessarily bulky technologically advanced apparatus such as:

circa Fall 1942 - Radar directed targeting (following in the footsteps of the decidedly more venerable (but no less effective) Swordfish).
Circa Fall 1943 - Naval night, radar directed intercept operations using Bat Teams of paired TBF-1 F6F) 
Circa Fall 1943 - TBM-1Ds Night owl teams with Dome mounted ASD-1 RADAR antennas and sets (sometimes including the standard ASB Yagi array antennas and sets) paired with destroyers for aerial ASW detection and surface attack (The TBFs were apparently unarmed)
Circa fall 1944 - XTBF-3W was created mounting an APS 20 RADAR antenna providing the earliest (of which I am aware) Airborne Early Warning (and fighter direction) platform. Interesting considering arguably the most famous a/c carrying APS-20 was the EC-121, a much larger a/c powered by 4 engines!

Circa 1945-46 thru 1948 TBM-3Q was created as a dedicated ECM platform. 

Admittedly, the later Douglas AD Skyraider was employed to fulfill most of these same roles, replacing the TBF/M after the Grumman had provided a few years of valuable service. The point being: an early mini-skyraider might have been less able to provide the same early and pioneering advancement of naval aviation that was afforded the development of the TBF. 

Almost forgot, the roomy TBF was an effective Carrier On Board Delivery (COD) Aircraft.

Ooops, didn't see SR6's or Conslaws similar earlier posts… (SR6's embellished with a very nice photo)


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## GregP (Mar 11, 2015)

Hey Shortround,

Those are some great points above about better cooling for the radials.

Even in the Bearcat, it COULD go fast but was generally cruising around at economy cruise speeds when not in combat to extend range and flight time. For most of WWII they didn't know where the other ships and planes were, so it paid dividends to save as much fuel as possible so you had more if combat was joined at some point.

Very late in the war we sometimes DID have the enemy on radar, but the planes still cruised around at economy speeds until acceleration to combat speeds was warranted.

Never any sense in wasting fuel or flight time ... unless you are racing for money.


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