TBF Avenger obsolete in light of SBD Dauntless SB2C Helldiver?

[gjs238]

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.

 

[Capt. Vick]

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".

 

[pbehn]

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.

 

[tyrodtom]

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 ?

 

[GrauGeist]

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.

 

[RCAFson]

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.

These problems were greatly reduced by the latter years of the war. Torpedoes had fin stabilizers, nose drag rings and tail shroud rings added, all of which worked to slow the torpedo after it was dropped so that it struck the water nose-first and at an acceptable speed. These improved the drop characteristics such that the recommended aircraft maximum launch parameters were increased to a height of 2,400 feet (730 m) and a speed of 410 knots.
USA Torpedoes of World War II

 

[RCAFson]

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.

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.

 

[GregP]

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.

 

[GrauGeist]

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.

 

[tomo pauk]

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.

 

[Timppa]

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

 

[Shortround6]

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.

 

[Capt. Vick]

Love the skypirate!

 

[tomo pauk]

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

 

[Shortround6]

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??)

 

[RCAFson]

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??)

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

 

[Shortround6]

Thank you.

 

[Timppa]

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.

 

[Shortround6]

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.

 

[GrauGeist]

...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...