Making sense of USN WWII dive/torpedo bomber projects

[Colonial-Marine]

I've been trying to understand he USN's various dive and torpedo bomber projects following the TBF/TMB Avenger and SB2C Helldiver. Ultimately these efforts led to the AM Mauler and AD Skyraider but there was a large number of designs prior to this. Would categorizing these aircraft into three distinct efforts be accurate?

1941 requirements dive bomber:

Douglas XSB2D - two seat dive bomber designed to succeed the troublesome SB2C Helldiver, two built
Curtiss XSB3C - cancelled in favor of the XSB2D before any prototypes built
Douglas BTD Destroyer - redesign of the XSB2D after revised 1943 requirements for a single seat aircraft, some sources claim it had worse performance, 26 built, further production cancelled in favor of newer designs

long range torpedo bomber (1943):

Grumman XTB2F - large two engine long range torpedo bomber, cancelled before prototype built
Grumman XTSF - two engine long range torpedo scout, derived from the F7F Tigercat, cancelled before prototype built
Douglas XTB2D Skypirate - large single engine long range torpedo bomber, cancelled after two prototypes
Grumman XTB3F - mixed power long range torpedo bomber
Grumman AF Guardian - redesign of the XTB3F into an anti-submarine aircraft, jet engine deleted

1943 requirement multi-role bomber:

Douglas XBT2D - single seat dive/torpedo bomber which became the AD Skyraider
Martin XBTM - single seat dive/torpedo bomber which became the AM Mauler
Curtiss XBTC - single seat dive/torpedo bomber rejected in favor of the Douglas and Martin designs, two prototypes built
Curtiss XBT2C - less ambitious dive/torpedo bomber reusing a large number of components of the SB2C Helldiver, second crewman in rear fuselage as a dedicated radar operator, nine built
Kaiser-Fleetwings XBTK - smaller single seat dive/torpedo bomber intended for escort carriers, cancelled after five prototypes

So a total of 11 different designs ordered by the Navy, 8 of which made it to prototype status, 3 of which saw service post-war.

 

[isayyo2]

Does Boeing's XF8B fit into this list?

 

[Colonial-Marine]

Does Boeing's XF8B fit into this list?

I think the Boeing XF8B came about more due a separate requirement the Navy developed with Boeing. I'm not sure how interested they were in using it as a dive or torpedo bomber but the ability to serve as a general-purpose fighter bomber (a role the F4U Corsair was proving the effectiveness of) had to be a good selling point. It's a shame the Navy didn't go forward with the XF8B but they must have viewed it as a fighter first and foremost and when it came to fighters jet engines were the future.

 

[isayyo2]

@Colonial-Marine
Thanks for the insight!

 

[robunos]

Regarding the Boeing XF8B-1, see HERE . . .

cheers,
Robin.

 

[Colonial-Marine]

Regarding the Boeing XF8B-1, see HERE . . .

cheers,
Robin.

Excellent article. I had thought it was viewed a bit more favorably in testing but I guess there is no getting over the fact that it was very large and heavy for a single engine fighter. A real "jack of all trades master of none" I suppose.

 

[tallguy]

Where does the Vultee TBV (naval Vengeance )come into the mix?

 

[BlackBat242]

Where does the Vultee TBV (naval Vengeance )come into the mix?

Pre-war (1940) export dive bomber designed for France, who ordered 372 in early 1940. First flight 30 March 1941.

Deliveries cancelled by the fall of France, 200 ordered by UK in July 1940, 100 more in December - saw combat mostly in Burma/India - a total of some 900 total purchased (501 directly from Vultee, bypassing US military controls).

After 7 Dec. 1941 US Army Air Force held onto some 243 of the British order, then ordered some 920 of a "better" version more to its liking.

The RAAF then ordered 400. 58 were still to be delivered when production of the type ended in March 1944 (other sources say only 121 delivered).

The total built was 1,931 (as for many WW2 aircraft the total numbers for each customer do not necessarily reflect actual production numbers, as contracts were frequently altered).

A torpedo-bomber version was proposed, but none were built.
No Vengeances of any variety were produced for the USN - the aircraft was a land-based-only program.

 

[tallguy]

Pre-war (1940) export dive bomber designed for France, who ordered 372 in early 1940. First flight 30 March 1941.

Deliveries cancelled by the fall of France, 200 ordered by UK in July 1940, 100 more in December - saw combat mostly in Burma/India - a total of some 900 total purchased (501 directly from Vultee, bypassing US military controls).

After 7 Dec. 1941 US Army Air Force held onto some 243 of the British order, then ordered some 920 of a "better" version more to its liking.

The RAAF then ordered 400. 58 were still to be delivered when production of the type ended in March 1944 (other sources say only 121 delivered).

The total built was 1,931 (as for many WW2 aircraft the total numbers for each customer do not necessarily reflect actual production numbers, as contracts were frequently altered).

A torpedo-bomber version was proposed, but none were built.
No Vengeances of any variety were produced for the USN - the aircraft was a land-based-only program.

Then why was the TBV designation applied? Lend Lease?

 

[BlackBat242]

Then why was the TBV designation applied? Lend Lease?

The only mention I can find for "TBV" is for the proposed and un-built torpedo-bomber version (TBV-1).

Vultee used the designation V-72 ( Vultee Model 72) for the French order, the UK used Vengeance I, Vengeance II, etc for theirs - and the US Army used A-31 & A-35 for theirs.

 

[P-STICKNEY]

Then why was the TBV designation applied? Lend Lease?

Could you perhaps be confusing it with the Vought TBU / Consolidated TBY?
Basically an R2800 powered competitor to the TBF, designed and prototyped by Vought, but priority put it on the back burner, so development was slow. Vought was going all out on Corsair production, so TBU production was transferred to Consolidated. (Hence the TBY) By the time production got going, all deployed Torpedo Bombers were Avengers, the Multi-Seat Torpedo and Dive Bombers were going to be replaced by Single Seat Attack Aircraft, so they never reached front-line units.

 

[P-STICKNEY]

I've been trying to understand he USN's various dive and torpedo bomber projects following the TBF/TMB Avenger and SB2C Helldiver. Ultimately these efforts led to the AM Mauler and AD Skyraider but there was a large number of designs prior to this. Would categorizing these aircraft into three distinct efforts be accurate?

1941 requirements dive bomber:

Douglas XSB2D - two seat dive bomber designed to succeed the troublesome SB2C Helldiver, two built
Curtiss XSB3C - cancelled in favor of the XSB2D before any prototypes built
Douglas BTD Destroyer - redesign of the XSB2D after revised 1943 requirements for a single seat aircraft, some sources claim it had worse performance, 26 built, further production cancelled in favor of newer designs

long range torpedo bomber (1943):

Grumman XTB2F - large two engine long range torpedo bomber, cancelled before prototype built
Grumman XTSF - two engine long range torpedo scout, derived from the F7F Tigercat, cancelled before prototype built
Douglas XTB2D Skypirate - large single engine long range torpedo bomber, cancelled after two prototypes
Grumman XTB3F - mixed power long range torpedo bomber
Grumman AF Guardian - redesign of the XTB3F into an anti-submarine aircraft, jet engine deleted

1943 requirement multi-role bomber:

Douglas XBT2D - single seat dive/torpedo bomber which became the AD Skyraider
Martin XBTM - single seat dive/torpedo bomber which became the AM Mauler
Curtiss XBTC - single seat dive/torpedo bomber rejected in favor of the Douglas and Martin designs, two prototypes built
Curtiss XBT2C - less ambitious dive/torpedo bomber reusing a large number of components of the SB2C Helldiver, second crewman in rear fuselage as a dedicated radar operator, nine built
Kaiser-Fleetwings XBTK - smaller single seat dive/torpedo bomber intended for escort carriers, cancelled after five prototypes

So a total of 11 different designs ordered by the Navy, 8 of which made it to prototype status, 3 of which saw service post-war.

I'd say that what you're seeing is the result of Combat Experience outpacing development. The 1941 Specs are calling for more of the Prewar concepts, but bigger and faster, but not fast enough. By 1943, combat experience showed that fighter escort was a better defense than gunners with limited arcs of fire.