Swordfish vs Devastator

[Shortround6]

The poor TBD never got some of the improvements the Swordfish got.

like radar, is there any reason it could not have been fitted had sets been available?
Range, hmm, take the 3rd crew man out and mount a big tin can in the middle of plane full of fuel, give the rear gunner a bag of corks to plug the bullet holes, range problem solved

comments have been made about it's short range and having only one forward firing gun and one gun out the back for defense.
Well the guns are exactly what the Swordfish had. and the TBD had a longer range and the same gun armament as the other US strike aircraft.

performance for a later version.

• Maximum speed: 234 mph (377 km/h, 203 kn) at 15,200 ft (4,600 m)
• Cruise speed: 175 mph (282 km/h, 152 kn)
• Range: 405 mi (652 km, 352 nmi)
• Service ceiling: 24,000 ft (7,300 m)
• Rate of climb: 1,630 ft/min (8.3 m/s)

This plane's prototype first flew about 8 months after the TBD prototype.
The TBD flew 2 years after and only 4 months after the production contract was placed for this aircraft

For those keeping track of technical innovation in 1933 this plane had a variable (two pitch) propeller and adjustable cowl flaps for adjustable engine cooling.

If we are going to compare the TBD to other aircraft lets compare it to contemporaries and please remember that the last TBD was ordered in 1938.
No more were built after early 1939 and no refit program with better engine/prop, electronics, armor, new fuel tanks etc was ever done.

 

[RCAFson]

The poor TBD never got some of the improvements the Swordfish got.

like radar, is there any reason it could not have been fitted had sets been available?
Range, hmm, take the 3rd crew man out and mount a big tin can in the middle of plane full of fuel, give the rear gunner a bag of corks to plug the bullet holes, range problem solved

comments have been made about it's short range and having only one forward firing gun and one gun out the back for defense.
Well the guns are exactly what the Swordfish had. and the TBD had a longer range and the same gun armament as the other US strike aircraft.
View attachment 610222
performance for a later version.

• Maximum speed: 234 mph (377 km/h, 203 kn) at 15,200 ft (4,600 m)
• Cruise speed: 175 mph (282 km/h, 152 kn)
• Range: 405 mi (652 km, 352 nmi)
• Service ceiling: 24,000 ft (7,300 m)
• Rate of climb: 1,630 ft/min (8.3 m/s)

This plane's prototype first flew about 8 months after the TBD prototype.
The TBD flew 2 years after and only 4 months after the production contract was placed for this aircraft
View attachment 610223

For those keeping track of technical innovation in 1933 this plane had a variable (two pitch) propeller and adjustable cowl flaps for adjustable engine cooling.

If we are going to compare the TBD to other aircraft lets compare it to contemporaries and please remember that the last TBD was ordered in 1938.
No more were built after early 1939 and no refit program with better engine/prop, electronics, armor, new fuel tanks etc was ever done.

The airframe was already at it limits in terms of weight, mainly because it was very lightly built. Additionally it was already overweight with full fuel and a torpedo and USN torpedoes got progressively heavier over time. There's just no reserve in the airframe to accommodate extra fuel and/or engine weight or drag.

 

[FLYBOYJ]

Those figures don't indicate a sufficient reserve range for safe mission planning. They are actually less than the Swordfish with no LR tank and 167IG internal fuel which was ~460nm at 5000ft with a 50min reserve. (Sturtivant - data based upon combat missions)

What is you basis for this? I always knew of 30 mins as a norm, you mention a 50 min reserve. Is this from a FAA directive or from the flight manual?

 

[Conslaw]

The TBD did ok for a plane that was developed in the heart of the Great Depression on a limited budget, produced in limited quantities, and hardly updated. By the time of Pearl Harbor, the Navy had commissioned, not one, but two replacements. the prototype for the Grumman TBF first flew in August 1941, and the prototype for the Vought (Later Consolidated) TBY Sea Wolf first flew December 1941. (Consolidated eventually delivered 180 Sea Wolves, almost as many as there were TBDs.) The TBD had the misfortune of having its most important crucible of fire (Midway) only weeks before it was going to be replaced.

In addition, the SB2C Helldiver was designed to have a secondary capability to take a torpedo instead of bombs. The SB2C's prototype first flew in December 1940, The Navy likely expected the SB2C to be in service by June 1942, but as we know the delays of the Helldiver are legendary.

The bottom line is that neither the US Navy nor Douglas saw much return in updating the TBD, not when it was about as easy to bring in a completely new design, a plane designed around an R-2600 or R-2800 engine, or even a Wright R-3350. By December 1941, Douglas had a contract to build prototypes for an aircraft to replace both the TBD and the SB2C. The prototype for this aircraft, designated XSB2D-1 eventually evolved into the BTD Destroyer, and 24 of these were delivered by V-J Day. A single-seat version of the BTD evolved into the AD/A-1 Skyraider.

 

[Shortround6]

The airframe was already at it limits in terms of weight, mainly because it was very lightly built. Additionally it was already overweight with full fuel and a torpedo and USN torpedoes got progressively heavier over time. There's just no reserve in the airframe to accommodate extra engine weight or drag.

Overweight in terms of the airframe breaking or overweight to poor power to weight ratio?

The early MK 13 torpedoes had a 400lb charge and weighed 1927lbs. Later ones got heavier but the early ones were what the plane was designed for.
Contemporary British torpedo went about 1548lbs with a 388lb charge. British did change warhead weights and other things in addition to fitting tails and nose protection.
US also went to a heavier warhead and wooden add ons.

Devastator might have had some rather amazing range if it used a 1600lb torpedo and carried an extra 50 gallons of fuel

Devastator used an early R-1830 that ran on 87 octane fuel and used light construction. A slightly later version running on 91 octane offered 150hp more for take-off and more cruising power higher up for less than 150lbs. AS used on PBY-3s

Would like to see where the overweight comment is from.

 

[Schweik]

The poor TBD never got some of the improvements the Swordfish got.

like radar, is there any reason it could not have been fitted had sets been available?

Yes, it was already barely able to handle the weight it was already carrying.

comments have been made about it's short range and having only one forward firing gun and one gun out the back for defense.
Well the guns are exactly what the Swordfish had. and the TBD had a longer range and the same gun armament as the other US strike aircraft.

The Swordfish had a longer range and could fly at night, though besides that, it too was a pretty obsolete aircraft. At least it was maneuverable.

What US strike aircraft had a shorter than than the TBD? Even the Vindicator had double it's range. And even the Vindicator had better armament. The SBD had two .50 cals in the nose. The TBF had a .50 cal defensive gun in a power turret. The B-26 was far more heavily armed etc.

If we are going to compare the TBD to other aircraft lets compare it to contemporaries and please remember that the last TBD was ordered in 1938.
No more were built after early 1939 and no refit program with better engine/prop, electronics, armor, new fuel tanks etc was ever done.

It never got the extra stuff because it didn't have the growth potential as a platform, that's why they went with the newer Grumman alternative.

But as we know very well, many aircraft ordered, designed and first flown in the 30's did have the chops to continue being used well into the war, some to the very end albeit sometimes in very different form. The TBF remained in service to the end of the war and after.

 

[Schweik]

The TBD did ok for a plane that was developed in the heart of the Great Depression on a limited budget, produced in limited quantities, and hardly updated. By the time of Pearl Harbor, the Navy had commissioned, not one, but two replacements. the prototype for the Grumman TBF first flew in August 1941, and the prototype for the Vought (Later Consolidated) TBY Sea Wolf first flew December 1941. (Consolidated eventually delivered 180 Sea Wolves, almost as many as there were TBDs.) The TBD had the misfortune of having its most important crucible of fire (Midway) only weeks before it was going to be replaced.

In addition, the SB2C Helldiver was designed to have a secondary capability to take a torpedo instead of bombs. The SB2C's prototype first flew in December 1940, The Navy likely expected the SB2C to be in service by June 1942, but as we know the delays of the Helldiver are legendary.

The bottom line is that neither the US Navy nor Douglas saw much return in updating the TBD, not when it was about as easy to bring in a completely new design, a plane designed around an R-2600 or R-2800 engine, or even a Wright R-3350. By December 1941, Douglas had a contract to build prototypes for an aircraft to replace both the TBD and the SB2C. The prototype for this aircraft, designated XSB2D-1 eventually evolved into the BTD Destroyer, and 24 of these were delivered by V-J Day. A single-seat version of the BTD evolved into the AD/A-1 Skyraider.

Near never heard of the TBY Sea Wolf ... seems like it never got into action until 1944. Pretty good performance & well armed, if it had come a bit earlier.

Consolidated TBY Sea Wolf - Wikipedia

 

[Schweik]

Overweight in terms of the airframe breaking or overweight to poor power to weight ratio?.

Well it could barely make 200 miles per hour and a rate of climb of 700 feet per minute, and it's crews said it handled like an overloaded truck. That sounds like either it was overweight for the engine or the wing or both, or just a bad design.

 

[FLYBOYJ]

The TBD did not have enough range. The TBD only carried 150IG of fuel, compared to 227IG for the Swordfish and a LR internal tank. It's very difficult to determine the actual range of the TBD but it seems pretty certain that it didn't have the range or endurance required unless the carrier moved somewhat closer to Taranto prior to launch.

What was the actual round trip undertaken by the Swordfish during Taranto?

 

[slaterat]

About 180 miles completed at night.

 

[RCAFson]

What was the actual round trip undertaken by the Swordfish during Taranto?

The nominal range at TO was 170nm, but night missions required more loiter time to allow for form-up, nav errors and landing on. The 1st range began TO at 2035 and the last aircraft returned at ~0200 for ~5hr 20min in the air. The 2nd range had TO starting at 2128, formed up and departed at 2145, nominal range 177nm, and returned at ~0230 for ~5hrs in the air.

 

[RCAFson]

Overweight in terms of the airframe breaking or overweight to poor power to weight ratio?

The early MK 13 torpedoes had a 400lb charge and weighed 1927lbs. Later ones got heavier but the early ones were what the plane was designed for.
Contemporary British torpedo went about 1548lbs with a 388lb charge. British did change warhead weights and other things in addition to fitting tails and nose protection.
US also went to a heavier warhead and wooden add ons.

Devastator might have had some rather amazing range if it used a 1600lb torpedo and carried an extra 50 gallons of fuel

Devastator used an early R-1830 that ran on 87 octane fuel and used light construction. A slightly later version running on 91 octane offered 150hp more for take-off and more cruising power higher up for less than 150lbs. AS used on PBY-3s

Would like to see where the overweight comment is from.

The TBD carried it's torpedo semi recessed so it wasn't really possible to carry a different design, and it was designed around the Mk13 (as was the TBF) rather than being able to carry generic designs as per the Swordfish. Max designed overload TO weight with full fuel and torpedo was 10176 lb but by 1942 max TO weight was pushing 10400lb due to armour, avionics and armament mods. Designed mission weight with a torpedo was only 9300lb (and 97usg of fuel!!! and 248nm) and after that there was increased G load restrictions, and even with 100usg burned, gross weight would still be ~9800lb.

A mid 1941 RN Mk XII torpedo weighed 1610lb and carried a ~440lb warhead.

 

[XBe02Drvr]

The ginormous TBF was not exactly a graceful design

Stand next to a TBF when you get a chance. It's a plane you can truly look UP to.

 

[Peter Gunn]

I dunno, harshing on a stressed skin monoplane with an enclosed cockpit that was designed in 1934 (amidst a score of fabric covered biplane, open cockpit designs) for failing in hitting KdB in 1942 (when it was already recognized as obsolete and being phased out) without any fighter protection seems rather disingenuous to me.

Strangely, it seemed able to survive and contribute from December 8, 1941 from the Marshal and Gilbert islands, Wake and Marcus island raids, strikes around New Guinea through the battle of the Coral Sea (helping sink Shoho) in 1942 without falling out of the sky because it was such an awful design. Perhaps that bit of history needs revision, maybe the old TBD didn't actually accomplish these feats and we should just write those off as wartime propaganda and patriotic chest thumping?

 

[Schweik]

Not chest thumping here, I just think it was a bad design. The stats don't lie.

 

[SaparotRob]

The TBD was perhaps a bad design but, imho, it was a great prototype.
As outlined above, it had a list of firsts. As pointed out above, the USN knew it served its purpose and was being replaced. ( See post #444). In isolationist America, that was happening as "fast" as it could. World War Two just happened sooner than expected. It flew in one battle too many.

 

[Schweik]

But many of the earlier war designs from (roughly) the same vintage proved to have much better potential. Partly this is because a torpedo bomber is such a difficult design challenge. But it was a pretty marginal design.

 

[FLYBOYJ]

The nominal range at TO was 170nm, but night missions required more loiter time to allow for form-up, nav errors and landing on. The 1st range began TO at 2035 and the last aircraft returned at ~0200 for ~5hr 20min in the air. The 2nd range had TO starting at 2128, formed up and departed at 2145, nominal range 177nm, and returned at ~0230 for ~5hrs in the air.

About 180 miles completed at night.

So a few things (regressing back to earlier posts)

There was mention of "safe mission planning." I don't know where that taken from but depending on aircraft, operations and operators, there can be anything from a calculated fuel reserve based on time in the air (30 minutes has been a norm in many aviation communities for years) or a percentage of calculated fuel remaining. I seen B-17 flight manuals that talk about certain mission profiles that required either a 5 or 10% fuel reserve.

Since I don't have a TDB flight manual in front of me (I looked at an early SBD flight manual and it had all kind of charts except one for range calculations based on cruise settings) I'll use the internet source of 435 miles for the range of the TBD. I'll also assume that range was based on operating at cruising speed which was shown as a whopping 128 mph. Rough calculations give me about 3 hours and 10 minutes in the air. So since we don't have fuel consumption charts and just have to go off internet numbers, let's subtract 20% of the range given, this accounts for a 10% fuel reserve and 10% for higher power settings during takeoff, formation form up and combat. Take that 20% away from the google flight manual reference of 435 miles, that gives the TBD a combat radius of about 175 miles, enough range to marginally complete the Taranto raid, at least on paper.

Do I think the TBD could have done the Taranto raid? Based on the way it was actually carried out, no way!

As mentioned, the TBD, for the mid 30's was state of the art but was quickly eclipsed by development. At the end of the day it was a lumbering truck that should have been replaced before Pearl Harbor and I do think it's limited successes were based more on luck and perhaps the skill, determination and bravery of the crews that flew them.

With THAT said, do I think the Swordfish would have performed any better at Midway if deployed under the same conditions? - NO. I think the results would have been the same or worse. And before someone tries to say that the Swordfish was more maneuverable than the TBD and "could have" evaded better, the Japanese pilots flying CAP that day were the best in the world and I'm sure would have had no problem adjusting firing solutions for a target moving under 100 mph.

I believe the Swordfish's ability to "grow" (take on radar) and it's low speed handling characteristics contributed to it's use well beyond it's obsolescence.

 

[Clayton Magnet]

I dunno, harshing on a stressed skin monoplane with an enclosed cockpit that was designed in 1934 (amidst a score of fabric covered biplane, open cockpit designs) for failing in hitting KdB in 1942 (when it was already recognized as obsolete and being phased out) without any fighter protection seems rather disingenuous to me.

I'd agree, it is like giving the Fairey Battle a hard time for its performance in the Battle of France, both the TBD and Battle were spaceship-like advanced in the mid 30's. I wonder if given the option in 1939, would the RN had swapped every Swordfish in its inventory for Devastators. The FAA pilots were probably looking enviously across the Atlantic at the sleek metal monoplanes of their cousins

 

[Schweik]

But the Bf 109, the Ju 87, the Hurricane, the B-17, all had their first flight in 1935. The Spitfire in 1936. Not all mid-30's aircraft turned out so dismal.