Why the Skua Only Carried a 500lb Bomb

[RCAFson]

Great Lakes TG2 124 mph top speed 56 mph landing speed, 656sq.ft area and 4155 pounds of payload. 200 gallons of fuel. Cruising speed 96 mph. The TG-2 was a slightly improved T4M from Martin that dated to 1928, but more powerful 620HP Wright Cyclone in place of the P&W Hornet. These stayed in service til 1938

Fairey Swordfish 138 mph top speed, 104mph cruising speed, 46mph landing speed 607sq.ft and 4000 pound payload 201 gallon tank, optional 82 gallon tank in observers place

Blackburn Shark MkII 152 mph top speed, 62 mph landing speed, 489sq.ft area and 4011 pounds of payload, 171 gallon tank. optional 150 gallon tank. Cruising speed 118 mph

Devastator had a 206mph top speed, 128mph cruising speed, 63 mph landing speed, 422sq.ft area and 4594 pounds of payload, 207 gallon tank.

Swordfish was able to stay in service, from Allied air supremacy.

The Shark was replaced in frontline service by the Swordfish prior to Sept 1939.

TBD performance was far less than it's claimed stats as evidenced by pilot statements up to Midway. In any event it and the TG2 were not stressed for divebombing and the TG2 had fixed wings. Again, these aircraft were not operable from RN carriers.

 

[marathag]

Quote:

"The B239Es were taken to Trollhättan, Sweden (the home of Saab Aircraft) where the Finns replaced the flight instruments with metric calibrated units, installed four 12.7-mm machine guns, armour plate behind the pilot's seat and self-sealing tanks...."

Nordic Buffalos — How An Obsolete U.S. Navy Fighter Found a New Lease on Life in Finland's War with the Soviets - MilitaryHistoryNow.com

“Despite their superiority in numbers and their losses, the Soviet’s never gained air superiority. That belonged to the Finns.” By Marc Liebman BY THE END of the Russo-Finnish War in March 1940, military planners in...

militaryhistorynow.com

In it's Finnish modified form the F2A would not have been operable from a carrier, at least for any length of time before it's LG would have failed.

What was the weight of the -239s vs the porky F2A-3?

 

[Shortround6]

...........................................................................239..................................F2A-3
Empty............................................................3744.................................4372
Gross, 4guns, 110gal of fuel................5276..................................6321
Max gross....................................................5314.................................7159

remember that the engine in the F2A-2 was 270lbs heavier than the engine in the 239 just to start things off.

 

[SaparotRob]

Quote:

"The B239Es were taken to Trollhättan, Sweden (the home of Saab Aircraft) where the Finns replaced the flight instruments with metric calibrated units, installed four 12.7-mm machine guns, armour plate behind the pilot's seat and self-sealing tanks...."

Nordic Buffalos — How An Obsolete U.S. Navy Fighter Found a New Lease on Life in Finland's War with the Soviets - MilitaryHistoryNow.com

“Despite their superiority in numbers and their losses, the Soviet’s never gained air superiority. That belonged to the Finns.” By Marc Liebman BY THE END of the Russo-Finnish War in March 1940, military planners in...

militaryhistorynow.com

In it's Finnish modified form the F2A would not have been operable from a carrier, at least for any length of time before it's LG would have failed.

Great article! I spent way too much time looking at the picture of the Buffalo.

 

[Shortround6]

From wiki

"It was the first American carrier-based monoplane to be widely used,
the first all-metal naval aircraft,
the first with a completely enclosed cockpit,
the first with power-actuated (hydraulically) folding wings."

Were there things wrong with it? sure.
However like the Skua, there was no MK II version. The Guys at Midway were using the same 850-900hp engines (running on 87 octane fuel?) that they had been built with in 1937-38.
Same engines used in the PBY-2 flying boats, the PBY-3s got 1050hp engines. PBY-5s got 1200hp engines.

Part of the range problem was the US MK 13 torpedo. It was about 500lbs heavier than the British torpedo so they had to loose 500lbs somewhere else, like fuel.
The MK 13 torpedo was only slightly more aerodynamic than a parachute.

two position torpedo mount?
One does wonder if they could have gotten rid of those fore and aft strips on wing for reduction in drag?

 

[SaparotRob]

…only slightly more aerodynamic than a parachute.
View attachment 717380

 

[planespotting]

The TBD Devastator's torpedo was, as I understand these things, utterly useless... except for the fact that its fuel was a drinkable alcoholic beverage, and when mixed with pineapple juice, provided a palatable hooch for the officially alcohol-free US Navy.

In contrast, I have nothing but enthusiasm for the Dauntless's fairly unique ability get a particularly large weight of metal horizontally off one carrier's deck and return it vertically onto another one, allowing a single aircraft to play steampunk Luke Skywalker... but it's not really supposed to do anything else, in contrast with the Skua, which is basically a Val - designed to mob opposing heavy units in larger numbers using 500lb GP - that's supposed to double as a fighter and has all the sensible carrier-plane stuff like folding wings, catapult stress, and the ability to float when crashed...

Vindicator was better than the Skua. Hell, the Curtiss SBC Helldiver Biplane was better than the Skua

As someone else has said, the Vindicator/Chesapeake couldn't dive-bomb, and I'm not sure how easily it could get off a deck with a useful cargo in the first place... it rather shows up the speed performance of Fleet Air Arm fighter types, but not the dive-bomber part...

The Val, with its fixed undercarriage, seems to have outperformed both the Skua and the Vindicator, which is perhaps more shocking...

Me, I'd advocate for Bristol just making one or two small radials by 1935-ish. Pegasus is a given; where the Pegasus cannot fit install Mercury; ditch Perseus and Taurus (bar as prototypes).

That seems logical...

One account of the Skua says it got the Perseus after the two prototypes got Mercury's because all the Mercury's were being allocated to Blenheim's.
In fact there was a shadow factory built to make Mercury's which may explain the preponderance of Mercury engines compared to other 3.

I have no idea if there was any parts interchangeable between the engines (Taurus may have used a few nuts, bolts, washers) the Mercury and Pegasus used the same diameter cylinders. Don't know if the heads were the same or any of the valve gear. The Perseus also used the same diameter cylinders and the same stroke as the Mercury but with the sleeves holding the piston and rings nothing outside the crankcase would be the same and a lot of stuff inside would be different.

The big problem Bristol had in 1939-40 and later was sleeve production. They thought they had it solved in 1938-39 but they could not maintain quality in volume production and since the Hercules and Perseus used the same cylinders (or at least the same size) it turned out that for every 3 Perseus engines you could have built two Hercules (sort of, 27 cylinders vs 28 cylinders) .
This may (Guess by me) the reason that around 1/2 of the Lysanders built had Mercury engines. This includes 150 0f the Canadian production (after the first 75 got Perseus) ALL the Lysanders III, all the Lysanders IIIAs and the 100 TT.MK IIIA target tugs (only ones specially built and not converted.)

The story of all these switcharounds seems rather odd...

1. As I understand it, circa 1936 the Mercury was allocated for the Blenheim, the Skua and the Lysander, while the Perseus was allocated for the M.15/35 twin-engined, narrow-fuselage torpedo-bomber project that became the Botha (though even here, I've seen a statement that the original engine allocated was the Aquila, and that the parallel Bristol Beaufort retained this, with only the Botha being swapped over).

2. The torpedo-bomber became a wide-body aircraft with a side-by-side cockpit and a more flexible carrying capacity, but while the Beaufort was allowed to upgrade to the Taurus in mid-1937, the Botha was made to keep the now-underpowered Perseus; meanwhile, the Skua and the Lysander were both swapped from the Mercury to the Perseus, first flights with the new motor being in August and December 1938. Was all this really to free up Mercury capacity for the Blenheim, or to make use of the Perseus?

3. In a quite separate line of engine production, the Miles Master was due to upgrade from the Kestrel to the Peregrine, which was also assigned for the Whirlwind... but in October 1939, the Air Ministry ordered the cancellation of the Whirlwind to switch the floor space and workforce to make more Lysanders (which seems to imply even more Perseus engines); this caused the cancellation of the Peregrine, so the Miles Master was hastily ordered to switch to the Mercury.

4. In the event, a proportion of Lysander production continued to be engined with the Mercury, switching fully back to that motor in August 1940; on the other hand, although a proof-of-concept Miles Master with a Mercury flew in late 1939, the plane continued to come off the production line with the Kestrel until I think 1941, when it switched over to the Mercury; I'm less clear over the Blenheim; I'd assume the Mk. IV continued in production until it was superceded by the Bisley (for which the internet gives an in-production date of in November 1941) and Mercury-engined Bolingbroke in Canada, but I'm not totally sure...?

Any corrections or commentary?

Big airframe will be more amenable for increased fuel load vs. size. Problem with big airframe is that bigger size means bigger drag, and bigger drag means a slower A/C, that will tend to use the fuel in a more prodigal fashion.
People wanting to have long range/long endurance fighters in ww2 will need to recall that droppable fuel tanks were in use already inn early 1930s, and act accordingly.

How much more drag does a longer airframe produce, though? All I know about drag along the sides of the plane is that no-one realised that that the air along the side of the fuselage needed to travel through the same space as the air over the wing root, except possibly the people who designed the English Electric Lightning...

The 72 knot stall speed was 'all up' LG and flaps raised. Stall speed was ~66 knots in landing condition with flaps and LG extended according to Wings of the Navy.
yeah, the speed itself isn't bad, but sudden stall behavior you don't want.

Devastator had a 63 mph landing speed, B5N Kate had a 72 mph landing speed

SBD had a 57 knot landing speed with full flaps and low fuel, to 73 knots , if trying to land at max take-off weight.

Leaving flaps up, added 8-11 knots to landing speed
stall behavior seems to have been to drop the left wing, but no warnings on a spin after that.

So the issue is less the landing speed than the abrupt sideways plunge out of the sky?

And, again a question that shows that I know nothing, would planes decelerate that much in combat?

Moxie means chutzpah.

I've certainly not been accused of lacking the Scottish equivalent, though I'm not sure we have a word for it in quite the same way...

 

[tomo pauk]

How much more drag does a longer airframe produce, though? All I know about drag along the sides of the plane is that no-one realised that that the air along the side of the fuselage needed to travel through the same space as the air over the wing root, except possibly the people who designed the English Electric Lightning...

Longer fuselage will have the more favorable lenght/width ratio than a shorter fuselage that has the same width; we assume here a V12 powered ww2 fighter comparison, with crew one behind another. Cue the 20th century ships, where ~10:1 length/beam ratio was often used on fast ships (cruisers, battlecruisers), and 7-8:1 on not so fast ones ('normal' battleships). Also, cue the thickness to chord ratio on the fighters' wings, where 13-15% was a much better call than 17-19% wrt. drag of the wing (assuming same/similar profile series).

 

[buffnut453]

The Devastator had less range than the Swordfish, wasn't stressed for divebombing, and it's STOL and wing fold characteristics meant it wasn't operable from RN carriers, much less escort/MAC carriers, where the Swordfish soldiered on until 1945. The Swordfish was intended for replacement by the Albacore in 1939, but had to carry on as the Albacore was delayed into service by engine production problems. By May 1941 the Swordfish was fitted with ASV radar, and yet could still carry a full weapons load including the much superior RN Mk12 torpedo. The Devastator would have been completely useless for the FAA.

It's difficult to imagine how the F2A-1, with it's completely inadequate armament, would have faired against Luftwaffe bombers in 1940. Increasing the armament led to a vicious cycle of LG failure, which made the F2A a less than carrier capable fighter.

Any serious research into the Vindicator will reveal that it wasn't capable of true divebombing as it had no effective divebrakes. A large number ended up in UK service where it was found to be unsuitable for combat operations.

Only the SBC-4, which entered service after the Skua could be considered equivalent to the Skua in terms of performance, but it had fixed wings, less range and only a single .3in forward firing MG. Why would the FAA want this aircraft?

Devastator might have had better performance as an airframe but as a weapon system it was entirely useless due to the poor reliability of the USN's torpedoes. It would be like delivering the best fighter aircraft in the world but installing guns that never fired successfully. I'm not blaming the Devastator airframe for the torp problems but if the aircraft can't actually perform the mission it was built to meet, then it can hardly be described as "better" than anything.

 

[MikeMeech]

The story of all these switcharounds seems rather odd...

1. As I understand it, circa 1936 the Mercury was allocated for the Blenheim, the Skua and the Lysander, while the Perseus was allocated for the M.15/35 twin-engined, narrow-fuselage torpedo-bomber project that became the Botha (though even here, I've seen a statement that the original engine allocated was the Aquila, and that the parallel Bristol Beaufort retained this, with only the Botha being swapped over).

2. The torpedo-bomber became a wide-body aircraft with a side-by-side cockpit and a more flexible carrying capacity, but while the Beaufort was allowed to upgrade to the Taurus in mid-1937, the Botha was made to keep the now-underpowered Perseus; meanwhile, the Skua and the Lysander were both swapped from the Mercury to the Perseus, first flights with the new motor being in August and December 1938. Was all this really to free up Mercury capacity for the Blenheim, or to make use of the Perseus?

3. In a quite separate line of engine production, the Miles Master was due to upgrade from the Kestrel to the Peregrine, which was also assigned for the Whirlwind... but in October 1939, the Air Ministry ordered the cancellation of the Whirlwind to switch the floor space and workforce to make more Lysanders (which seems to imply even more Perseus engines); this caused the cancellation of the Peregrine, so the Miles Master was hastily ordered to switch to the Mercury.

4. In the event, a proportion of Lysander production continued to be engined with the Mercury, switching fully back to that motor in August 1940; on the other hand, although a proof-of-concept Miles Master with a Mercury flew in late 1939, the plane continued to come off the production line with the Kestrel until I think 1941, when it switched over to the Mercury; I'm less clear over the Blenheim; I'd assume the Mk. IV continued in production until it was superceded by the Bisley (for which the internet gives an in-production date of in November 1941) and Mercury-engined Bolingbroke in Canada, but I'm not totally sure...?

Any corrections or commentary?

Hi
You appear to have missed that the Mercury was also used on the Gloster Gauntlet and Gladiator, Miles Martinet and all the British built Blenheims Mks. I, IV and V (Bisley) had Mercury engines, as did the Supermarine Sea Otter.

Mike

 

[Shortround6]

Priorities and allocations changed with time and please remember, allocations could take place 1-2 years before actual airframe production or delivery.

In 1937-38 and 39 the Blenheim was a hot item, in 1940 not so much and in 1941 it was "we have several factories tooled up for them, they aren't really good for much but it will take 1-2 years to build anything better (and may require engines from the US)"
Repeat for several other aircraft.

The Miles Master was built to take advantage of hundreds of RR Kestrels sitting in warehouses after overhaul, When they started running out of those the switched to the Mercury. They later switched to the P & W R-1535 twin Wasp junior, which must have been another warehouse deal. Nobody in the US or Canada really wanted anything to do with an 800-825hp 14 cylinder engine in 1941-42. Perhaps they were left over French engines ordered for the Breguet 695??

 

[marathag]

So the issue is less the landing speed than the abrupt sideways plunge out of the sky?

I phrased that poorly. A Stall, some aircraft will mush on down, staying level, others will start to drop one wing or the other but managable, while the worst will drop a wing followed by something bad, like a spin.
Dauntless was #2, Skua #3

Corsair was also a #3

 

[marathag]

One does wonder if they could have gotten rid of those fore and aft strips on wing for reduction in drag?

USN should have asked for a more refined TBD, with uprated engine and windtunnel work.
Torpedo placement was a design requirement, as rather than a recessed mount or bay, there had to be an area for the bombardier to lie prone and use the new norden bombsight for level bombing.

Douglas should have spent some money on trying to interest the USN on a TB2D rather than wasting all that $$$ on the XB-19

 

[RCAFson]

USN should have asked for a more refined TBD, with uprated engine and windtunnel work.
Torpedo placement was a design requirement, as rather than a recessed mount or bay, there had to be an area for the bombardier to lie prone and use the new norden bombsight for level bombing.
View attachment 717483
View attachment 717484
Douglas should have spent some money on trying to interest the USN on a TB2D rather than wasting all that $$$ on the XB-19

Let's replace the TBDs used at Midway with Swordfish (or better yet Albacores).

The smaller footprint of the Swordfish will allow for more aircraft per squadron; say 18. About 5 hours before dawn, TF16 and 17 fly off 12 ASV equipped Swordfish with LR fuel tanks and (hopefully) locate the KB.

The rest of the Swordfish are then flown off for a predawn torpedo strike using their ASV radar to locate the KB, and they all return except for one or two unlucky enough to get hit by random flak.

Alternately, they are flown off for a dawn dive bombing strike armed with ~1500lbs of bombs.

Alternately, they are flown off for a day torpedo strike using a dive bombing mission profile (as per FAA doctrine).

Alternately, they are flown off for a day dive bombing mission.


Each of these mission plans was unavailable to USN TB squadrons because the TBD was incapable of performing them.

 

[Shortround6]

Douglas should have spent some money on trying to interest the USN on a TB2D rather than wasting all that $$$ on the XB-19

Trouble is that it was the Navy that was spending the money on the TBD and it was the Army that had contracted for the XB-19. Douglas did want to get out of it much earlier as they were loosing money but the Army insisted. Douglas had to complete the contract or loose future Army contracts.

 

[Shortround6]

Each of these mission plans was unavailable to USN TB squadrons because the TBD was incapable of performing them.

And the RN couldn't do some of the missions that the US air groups could do.

The Problem with some of the US carriers was not the size of the deck park but the size of of the magazines and the amount of aviation fuel, both were huge compared to the RN carriers but when you are operating 70-80 aircraft per strike at 140-180 US gallons per plane (12,000 US gallons per strike) you can run out of fuel pretty quick.

 

[RCAFson]

And the RN couldn't do some of the missions that the US air groups could do.

The Problem with some of the US carriers was not the size of the deck park but the size of of the magazines and the amount of aviation fuel, both were huge compared to the RN carriers but when you are operating 70-80 aircraft per strike at 140-180 US gallons per plane (12,000 US gallons per strike) you can run out of fuel pretty quick.

I've previously researched and crunched the numbers for avgas use by Enterprise at Midway. She used about 1/3 or less of her avgas during the entire operation (about 400 sorties with most returning with 10-20% fuel). Adding 4 more aircraft per carrier, especially given the simple construction of the Swordfish, shouldn't present a problem.

The Swordfish and Albacore (and even the Shark) could do every mission type that the TBD could do and the others (except I'm not sure if the Shark was stressed for DBing) as I mentioned above.

 

[SaparotRob]

I had looked into the TBD and Swordfish a while ago. The Admiral had brought up the "had the Swordfish been at Midway" what-if. I thought radar equipped Swordfish was a very interesting idea. I think the Swordfish might have pulled it off but the Shark?

 

[marathag]

The smaller footprint of the Swordfish will allow for more aircraft per squadron; say 18. About 5 hours before dawn, TF16 and 17 fly off 12 ASV equipped Swordfish with LR fuel tanks and (hopefully) locate the KB.

hopefully.
They take off early, cruising at 90 knots

What bearing? Radar gives around 60 miles notice, best case

Would VT8 still be bait to occupy the fighters to let the Divebombers thru? as it was for SBDs, 18 were lost from Fighters and Flak, around 40%
Could Swordfish do as well?

At full load of ordnance, you have 550 miles of range, but slower cruise than TBDs and SBDs

 

[MIflyer]

I think that the Skua could only carry a 500 pound bomb because a 500 KG bomb would have been too heavy.

Could someone provide a list of successful British dive bombers? I think it would be even shorter than a list of Russian Sports Cars.