Why the Skua Only Carried a 500lb Bomb

[SaparotRob]

I thought the radar directed battleship gunnery at Surigao was accurate, excepting USS Pennsylvania which had an older radar set.
I like your thoughts on the Skua. I never wondered why the engine was so far out or why all the bumps and and lumps were there. I just figured it was Blackburn being Blackburn.
Welcome to the Forum.

 

[planespotting]

Thank you for the welcome!! I've been reading the forum for years, always impressed by the level of discussion being bounced around, but never confident to do more than lurk; something about the... existential Blackburn-being-Blackburn eccentricity of the Skua seems to have impelled me to actually register and post.

(But I edited out my Suriago remark, as too off-topic)

 

[SaparotRob]

No topic is too off topic. There's usually a wealth of knowledge to be gained from our little detours.

 

[special ed]

Welcome on board now officially registered.

 

[Thumpalumpacus]

Hiyas, Spotter. Wasn;t the Skua's back-seater also used for navigation? I had thought this was an FAA doctrine.

 

[SaparotRob]

Don't short change the whole conversation thing.

 

[Thumpalumpacus]

Don't short change the whole conversation thing.

Yabut but did they have a pint or two?

 

[Shortround6]

Don't short change the whole conversation thing.

Well, the rear seater could offer a running commentary as to how the work was going using the homing beacon to find the carrier while the Pilot could update the rear seater as to the fuel status every few minutes
Scintillating conversation " Find the bloody carrier Bob, we are close to running on bleeding fumes here and I don't know how to swim!!!!"

 

[SaparotRob]

Just think of all the movie dialogues to be written.

 

[yulzari]

Hiyas, Spotter. Wasn;t the Skua's back-seater also used for navigation? I had thought this was an FAA doctrine.

Not as a navigator though. Normally a lowly Telegraphist Air Gunner whose main purpose was to operate the homing device that could find the carrier wherever it may have moved to. Of course a navigator could replace the TAG such as one in a strike group.

A read through the posts and related threads will answer many of your questions Spotter but the actual engine/performance item is worthy of informed comment.

A related question is why the Perseus and Mercury both remained in production at the same time given that they had a very similar performance?

 

[Reluctant Poster]

Well, the rear seater could offer a running commentary as to how the work was going using the homing beacon to find the carrier while the Pilot could update the rear seater as to the fuel status every few minutes
Scintillating conversation " Find the bloody carrier Bob, we are close to running on bleeding fumes here and I don't know how to swim!!!!"

That's a bit unfair. The rear gunner in the Dauntless was also a radioman-gunner and not a navigator. Everyone at the time thought a rear gunner was necessary for dive bomber.

 

[EwenS]

Apologies for tagging a belated tangent onto an interesting discussion, but one thing that probably needs to be ascertained is what the performance of the Skua actually was.

The quoted 225 mph looks suspiciously rounded, and I'm not sure how to establish whether this is a design specification, a figure obtained with the Mercury XII engine on the prototype (830hp on takeoff, 890hp at 6,000ft, 51.5" diameter, and a weight I can't find stated, but presumably approximately 1000lbs) or a service speed with the theoretically draggier and less powerful Perseus XII (830hp on takeoff, 750hp at 6,500ft, 55.3" diameter, 1025lbs).

This 225 mph figure is often quoted as the speed at 6,500ft, i.e. the optimised altitude of the Perseus XII, but this may be an extrapolation based on the assumption that that's the natural height to peg the figure to; in contrast, Peter Caygill's Flying To The Limit, presumably using RAE dociments, says 225 mph is actually a sea-level figure, which looks very like a design specification, but on the other hand, should perhaps improve with altitude. The Roc, with the Perseus XII and a draggy turret, is quoted in the same source at 223 mph at 10,000 feet - would the Skua be expected to do a bit better?

Spec O.27/34 that led to the Skua called for max speed 225mph at 6,500 feet.

"Wings of the Navy" by Eric Brown gives Skua speeds as follows:-
225mph max at 6,700 feet
204mph at sea level

"British Naval Aircraft since 1912"
225mph max at 6,500 feet
204mph at sea level

"Blackburn Skua & Roc" by Matthew Willis gives Skua speeds as follows:-
225mph max at 6,500 feet

"British Carrier Aviation" by Friedman
225mph (196 knots) max at 6,700 feet
204mph (177 knots) at sea level

Friedmaan uses the same figures in "Fighters over the Fleet" but with the following added comment:-
"In 1934, estimated maximum speed with a Perseus IIS engine (835hp at 15,000ft) was 203 knots [233mph] at 15,000ft. with a service ceiling of 30,000ft ...."

Moreover, as these number suggest, the supercharger on both motors was optimised for a relatively low altitude, so I'd imagine a motor optimised for high-level performance would get a slightly better top-line speed, simply because good power at high altitude translates to higher speed in the thinner, less draggy air.

But the RN expected to fight around 10,000 feet. That was seen as the ideal approach height for the torpedo bombers for which the Skua was to act as escort in one of its roles. The operational height of the Fulmar was specified in 1938 to be 10,000ft. Only with the 1939 & 1940 Specs was the operational height increased to 15,000ft.

The question is, what motor? There's definitely room for improvement, if both the engines the Skua was flown with were too light for the airframe, and had to be jettied out two and a half feet ahead of the firewall - does that indicate something about the design process? How much more can be got out of a single-row radial? Would one of the big twin-row radials in the 2,000lb weight class, powerful but half-a-ton heavier and correspondingly thirsty, be practical, or would a Merlin be a better alternative than any of them? The Bristol Taurus, a small twin-row, weighs not much over 1250lbs and gives around 1100hp, but it's optimised for 5,000ft and at closer to 45" diameter, would it be to small? Apparently Alvis had a licensed version of the Gnôme-Rhone Mistral Major with a 52" diameter and a weight of under 1200lbs which gave over 1,000hp on the bench and had a high-altitude supercharger, all tooled-up with nowhere to go because the Air Ministry couldn't think of a good use for it...

And quite apart from engines, there's something to be said for a better propeller - the Skua used a two-speed prop, where the blades could pivot between two settings, one for take-off power and the other either for most-economical cruise or fastest possible dash, I'm not sure which; I've seen it said that it could be manually set at angles between the two extremes, but I'm not sure if that's true, and the general view seems to be that automatic "constant-speed" units handled such variation better than the average pilot, giving both a quicker climb and faster acceleration from manoeuvres in a fight.

And what else could be improved? Is there something to be gained in swapping the back-seater, who only seems to be there for morse-code messages and conversation, for seatback armour and a sleeker cockpit canopy? Can we get something with more fighter-like performance that still dive-bombs? And if so, which fighter does it equate to? The Gladiator? Fulmar? Sea Hurricane?

Everyone should feel free to brutally demolish any nonsense in what I've written - I'm really just an observer from the ground, and may only be showing my ignorance...

But, set up like a row of coconuts, a few more random observations on topics that have been raised in this discussion:

* A 500lb SAP/GP is probably less than ideal in a naval role; but the limited weight can be compensated for by doing what the IJN's Vals did repeatedly, mob targets with a reasonably large number of planes - as to the effectiveness of the tactic against armoured capital ships, the obvious example is USS Nevada, caught by a half-dozen Val hits that would have foundered her if she'd been on the open sea and unable to beach herself;

USS Nevada
That is an over simplistic view of what happened to her, and just because it happened while in PH, it does not follow that the same would have happened had she been at sea. Look at the damage report.

Researcher@Large - BB-36 USS Nevada Pearl Harbor Attack Damage Report

Note that the first damage she suffered came from a torpedo hit while tied to the dockside and that started the flooding. At sea she could have manoeuvered to avoid it. Only 2 of the bomb hits let in any water at all. Again this happened while she was more or less stationary and before she was beached. Again being at sea gives the opportunity for avoidance.

The bulk of the flooding came from initial orders to counterflood after the torpedo hit, then from an error in flooding the after magazines as she sailed past Arizona, and which were not in any danger, and then from the flooding of the forward magazines due to a fire risk and subsequently determined unnecessary. She was beached because her anchor party had been wiped out while preparing the ship to anchor by the third bomb hit. Then having been beached she gradually flooded to a greater extent over the next two days.

The diagrams at the end of the report show what flooding occurred and whether caused by enemy or own actions.

So there are a lot of variables that might have played out entirely differently had she been at sea, meaning that it would be by no means certain that she would be lost.

HMS Warspite was sent to the rear for almost year by a couple of 500lb hits from Bf 109s, albeit Graf Zeppelin's specially-trained CAG, the Luftwaffe having decided that they didn't need to bother with the boat... beyond that, there simply aren't many examples, as the IJN switched to useless skip-bombing A6Ms and no-one sent Skuas against Tirpitz... but on the other hand, while the effects of a near miss by a large blast-bomb, raised in the previous Skua thread, certainly look impressive, the punchline there is that no-one actually noticed...

HMS Warspite
The story is not as simple as you lay it out.

See Burt "British Battleships 1919-1945" for a full description of the damage. There was only one hit (plus two near misses which did no damage). A part of the ships side was torn away and the starboard 6" battery disabled and the starboard forward twin 4" AA mount destroyed. She did not take on any water. Temporary repairs were made within a month, but it was decided to send her to the USN Puget Sound NY in California for repairs and a more general refit. In making that decision both Durban and Singapore were bypassed as possible repair sites.

Having been bombed on 22nd May 1941 her subsequent movements were:-
25th June - left Alexandria for Puget Sound with stops at Colombo, Singapore, Manila & Honolulu
10th Aug - arrived Esquimalt where part of her crew left for home
11th Aug - arrived Puget Sound where another part of her crew left for home.
Aug - Dec - under refit which included replacement of 5x15" guns and fitment of radars all of which had to be sent from the UK (note first set of radars were lost at sea and a second set sent as a rush order no doubt causing some delays)
28th Dec - recommissioned followed by work up on the Pacific coast with her new crew.
23rd Jan - sailed from Esquimalt for Sydney, routing south via the Pitcairn Islands to avoid the Pacific war.
20th Feb - arrived Sydney
22nd March - arrived Trincomalee via Fremantle after being delayed by warnings of submarine activity off the wetern Australian coast.

You might be conflating the hits on Warspite with two (and 2 near misses) 50kg bomb hits on Valiant at the same time. In her case the damage was minimal and her fighting efficiency unimpaired. All repaired in 2 months while at Alexandria.

Funnily enough there has been a discussion on another site about GZ and her air group. By May 1941 any connection with GZ it is to say the least tenuous given the turnover in aircrew that would have occurred in Luftwaffe units as a result of losses in the BoB. Here is the history as posted of the II./186(T) that became III./JG77 that was reponsible for the bombing of Warspite.

"Basically the history is:
I Gruppe formed 10 September 1939 at Kiel-Holtenau with a Stab and 3 Staffeln of Ju 87B, became III Gruppe StG.1 on 5 July 1940. From May the unit had already been taking part in operations in France as part of II. Fliegerkorps.

II Gruppe formation ordered 1 August 1938 at Bug/Rugen but cancelled 22 October. Reformed 1 November 1938 at Kiel-Holtenau: 4. (Stuka) Staffel with Ju87B, and 6.(Jagd) Staffel on 15 November 1938 with Bf 109B from 4./JG136. 5.(Jagd)/186 was formed 15 July 1939 and the Stab II./186 formed on 10 September 1939 .......
On 10 September 4./186 with its Ju 87Bs became 3./186 and moving to I Gruppe, being replaced by a new Bf 109-equipped 4. Staffel on 11 October, but which was disbanded in December 1939. Around this time the Bf 109E had replaced the older B-model fighters. Yet another new 4./186 was formed from 2./JGr.101 on 29 February 1940 but on 27 June it became 3./Erprobungsgruppe 210. On 5 July 1940 II Gruppe was redesignated III Gruppe JG77.

4./186 saw service in Norway during the latter stages of the Norwegian campaign (June) and 5./186 spent a month at Aalborg in Denmark (7 June - 5 July).
One unit was at Antwerp during 24 May - 2 June. "

* BuShips damage analysis may not be very reliable at any level more detailed than "big jagged hole in the hangar deck"; I've seen all kinds of things misidentified as hits on opposing capital ships by US Navy battleship main-guns, including a pair of 1,000lb bombs from SBDs (Jean Bart at Casablanca, 1942)...

* The one RAF aircraft that could and did dive-bomb was, of all things, the Westland Whirlwind, which dropped pairs of 250lb in an 80° dive (I think using the trim tabs to recover); why a twin-engined high-altitude interceptor was given this capability I do not know, except that it seems a very Petter thing to do. The problem with overspeeding mentioned in some sources was caused by an unsatisfactory two-pitch prop, which de Havilland solved on a wet wednesday in the Battle of Britain by clocking the blade angle round by about three degrees, but I don't think they ever got a constant-speed unit, which explains why they never met their design performance in the high-altitude interceptor role...

The Whirwind was modified to drop 2x250lb or 2x500lb bombs from Aug 1942 in the fighter bomber role. But I don't believe it was ever used as an 80 degree dive bomber.

This will explain the Whirlwind's propellor problems.

The Westland Whirlwind British fighter aircraft of WW2

dingeraviation.net

* Speaking of the advantages of large, thin-skinned blast-bombs, and random things that de Havilland did on their own initiative in 1940...

Is it possible that Luftwaffe officers were asking about the fact that Berlin had been reduced to rubble by two-ton drums of HE toted by unusually-shaped flying pianos?
View attachment 716196

It was April 1943 before RE Bishop of De Havilland suggested to NE Rowe of MAP that it might be possible to modify the Mosquito to carry a 4,000lb Cookie. Authorisation for a trial conversion of a Mk.IV was given on 29th April 1943. That aircraft DZ594 flew in July in its new form. The first converted aircraft were delivered to 692 squadron in Feb 1944 and flew their first missions on 23rd Feb.

Prior to that the max bomb load had been 4x500lb with shortened tails in the bomb bay and 2x500lb on underwing racks in the Mk.IX.

The MK.XVI illustrated in your photo, was the first version designed from the outset to carry the Cookie, and arrived in time for its first operations on 5 March 1944, with the first Cookies dropped on Berlin in April.

But I get the sense that Pathfinder Force didn't even tell Bomber Command what they were doing, so it's understandable that the USAAF might be confused...

The two Mosquito squadrons (105 & 139) were initially allocated to 2 Group for daylight sorties. In June 1943 they moved to 8 Group and 105 joined 109 in the Pathfinder role until the end of the war. 139 then split its time between Pathfinder & bombing roles, beginning nighttime nuisance raids on Germany and gradually being joined by other squadrons through 1944 as more Mosquito bombers became available. Those units formed the Light Night Striking Force within 8 Group. The Group Mosquito element built up to an eventual 11 squadrons in Jan 1945.

Not sure where you got the idea that the Pathfinder force wasn't telling anyone what they were doing. Harris authorised it all after all.

The version I've read is that their lack of aerodynamics actually made them more accurate, as they didn't tend to "fly" like the finned equivalent. Those with more knowledge than me might want to comment on the plausibility of this claim?

 

[Geoffrey Sinclair]

This 225 mph figure is often quoted as the speed at 6,500ft, i.e. the optimised altitude of the Perseus XII, but this may be an extrapolation based on the assumption that that's the natural height to peg the figure to; in contrast, Peter Caygill's Flying To The Limit, presumably using RAE dociments, says 225 mph is actually a sea-level figure, which looks very like a design specification, but on the other hand, should perhaps improve with altitude. The Roc, with the Perseus XII and a draggy turret, is quoted in the same source at 223 mph at 10,000 feet - would the Skua be expected to do a bit better?

Blackburn Skua, one 905 HP at 6,000 feet air cooled Perseus XII, span 46 feet, length 35 feet, height 12 feet 6 inches, wing area 319 square feet. 2 Crew wing armament 4 Browning with 600 rpg, dorsal 1 Lewis with 6 Mags. Normal and maximum bomb load 5000 pounds. RAF performance figures

Type	Type	Dive Bomber	Fighter
Weight	Tare (pounds)	5,839​	5,839​
Normal	Weight (pounds)	8,215​	8,115​
Normal	Take Off (Over 50 ft) (Yards)	670​	650​
Normal	Climb to Height (feet)	15,000​	15,000​
Normal	Climb to Height Time (Mins)	22​	21​
Normal	Service Ceiling (Feet)	19,000​	19,300​
Normal	Maximum Speed (m.p.h)	212​	213​
Normal	Max Speed Height (Feet)	15,000​	15,000​
Normal	Cruising Speed (m.p.h)	193​	194​
Normal	Cruise Speed Height	15,000​	15,000​
Normal	Bomb Load (pounds)	500​
Normal	50 Minutes allowance Range (miles)	466​	906​
Normal	50 Minutes allowance Endurance Hours	2.93​	4.67​
Normal	Fuel (for range, pounds)	706​	1,080​
Normal	Fuel (for allowance, pounds)	142​	142​
Normal	Fuel (Total, pounds)	848​	1,222​
Normal	Fuel (Total, Gallons)	163​	163​
Normal	Miles per 100 pounds fuel	80.2​	83.9​
Extended	Overload Weight (pounds) (Max bombs (or Fuel if same))	8,625​	8,115​
Extended	Take Off (Over 50 ft) (Yards)	770​	650​
Extended	Climb to Height (feet)	15,000​	15,000​
Extended	Climb to Height Time (mins)	25​	21​
Extended	Service Ceiling	18,000​	19,300​
Extended	For Maximum Bombs (Cruise)
Extended	Speed (m.p.h)	190​
Extended	Height (feet)	15,000​
Extended	Bomb Load (pounds)	500​
Extended	Range (50 mins allow.) (miles)	890​
Extended	Endurance (50 mins allow.) Hrs	4.7​
Extended	Fuel (for range, pounds)	1,080​
Extended	Fuel (for allowance, pounds)	142​
Extended	Fuel (Total, pounds)	1,222​
Extended	Fuel (Total, Gallons)	163​
Extended	Miles per 100 pounds of fuel	82.5​
Extended	For Maximum Fuel (Economical)
Extended	Speed (m.p.h)	157​	156​
Extended	Height (feet)	15,000​	15,000​
Extended	Bomb Load (pounds)	500​
Extended	Range (50 mins allow.) (miles)	980​	1,025​
Extended	Endurance (50 mins allow.) Hrs	6.25​	6.57​
Extended	Fuel (for range, pounds)	1,080​	1,080​
Extended	Fuel (for allowance, pounds)	142​	142​
Extended	Fuel (Total, pounds)	1,222​	1,222​
Extended	Fuel (Total, Gallons)	163​	163​
Extended	Miles per 100 pounds of fuel	91​	95​

* A 500lb SAP/GP is probably less than ideal in a naval role; but the limited weight can be compensated for by doing what the IJN's Vals did repeatedly, mob targets with a reasonably large number of planes - as to the effectiveness of the tactic against armoured capital ships, the obvious example is USS Nevada, caught by a half-dozen Val hits that would have foundered her if she'd been on the open sea and unable to beach herself; HMS Warspite was sent to the rear for almost year by a couple of 500lb hits from Bf 109s, albeit Graf Zeppelin's specially-trained CAG, the Luftwaffe having decided that they didn't need to bother with the boat... beyond that, there simply aren't many examples, as the IJN switched to useless skip-bombing A6Ms and no-one sent Skuas against Tirpitz... but on the other hand, while the effects of a near miss by a large blast-bomb, raised in the previous Skua thread, certainly look impressive, the punchline there is that no-one actually noticed...

USS Nevada was torpedoed between her forward turrets before getting underway, then ordered to stop as it became clear to local command the Japanese were trying to sink her in the habour channel, something that would bottle up the fleet. Total of 5 bomb hits, plus torpedo plus delberate flooding of the magazines plus counterflooding to correct the torpedo induced list pushed the waterline above the highest water tight deck. The USN commented on the effects of near misses when repairing Illustrious. Warspite, damaged 22 May 1941, arrived in the US for repairs 11 August (via the Pacific) recommissioned 28 December.

* The one RAF aircraft that could and did dive-bomb was, of all things, the Westland Whirlwind, which dropped pairs of 250lb in an 80° dive (I think using the trim tabs to recover); why a twin-engined high-altitude interceptor was given this capability I do not know, except that it seems a very Petter thing to do. The problem with overspeeding mentioned in some sources was caused by an unsatisfactory two-pitch prop, which de Havilland solved on a wet wednesday in the Battle of Britain by clocking the blade angle round by about three degrees, but I don't think they ever got a constant-speed unit, which explains why they never met their design performance in the high-altitude interceptor role...

The Whirlwind was the medium altitude bomber destroyer, the Welkin the high altitude interceptor. The Whirlwind was adapted as a fighter bomber, which operations used 80 degree dives? The wing cells in the Fairey Battle could release their bombs safely in an 85 degree dive.

* Speaking of the advantages of large, thin-skinned blast-bombs, and random things that de Havilland did on their own initiative in 1940...
Is it possible that Luftwaffe officers were asking about the fact that Berlin had been reduced to rubble by two-ton drums of HE toted by unusually-shaped flying pianos?

(Tail less bombs) Quite sure, consider how easy it is to see bombs falling at night. And it was the USSBS post war including examination of the dud bomb dumps. The US proved quite conclusively heavier bombs were more accurate.

At Surigao Strait West Virginia, Tennessee and California had the latest fire control, Maryland used the West Virginia shell splashes, Mississippi fired two salvos, Pennsylvania did not fire.

 

[tomo pauk]

The question is, what motor? There's definitely room for improvement, if both the engines the Skua was flown with were too light for the airframe, and had to be jettied out two and a half feet ahead of the firewall - does that indicate something about the design process? How much more can be got out of a single-row radial? Would one of the big twin-row radials in the 2,000lb weight class, powerful but half-a-ton heavier and correspondingly thirsty, be practical, or would a Merlin be a better alternative than any of them? The Bristol Taurus, a small twin-row, weighs not much over 1250lbs and gives around 1100hp, but it's optimised for 5,000ft and at closer to 45" diameter, would it be to small? Apparently Alvis had a licensed version of the Gnôme-Rhone Mistral Major with a 52" diameter and a weight of under 1200lbs which gave over 1,000hp on the bench and had a high-altitude supercharger, all tooled-up with nowhere to go because the Air Ministry couldn't think of a good use for it...

As for the majority of aircraft, having the Merlin is an upgrade. Big 2-row radials of 2000 lbs might be a bit too much of a good thing.
Taurus being small is/was a good thing, what was not good was that Taurus on itself was never considered as a win, and required 100 oct fuel to make about 1100 HP, despite being a spanking new design. Installing a Pegasus would've been improvement over the Perseus, IMO.
G&R Mistral Major as made at Alvis (the 'Pelides') was not with a high-altitude S/C, rated altitude was at 7500 ft, where 975 HP was produced.

And what else could be improved? Is there something to be gained in swapping the back-seater, who only seems to be there for morse-code messages and conversation, for seatback armour and a sleeker cockpit canopy? Can we get something with more fighter-like performance that still dive-bombs? And if so, which fighter does it equate to? The Gladiator? Fulmar? Sea Hurricane?

Backseater has it's role in the FAA in the late 1930s-early 1940s, not just to operate the homing device.
Equaling Gladiator and Fulmar wrt. speed might be done with a Merlin X on board. Equaling Sea Hurricane - not likely. Keeping the Skua firmly in the dive bombing role would've been the best, IMO, and provide some meaningful fighter escort in the meantime.

 

[elbmc1969]

As mentioned, the Telegraphist/Air Gunner was necessary for homing on the carrier's beacon. The British system was not user-friendly and was eventually replaced by the American system.

Also, not having a tail gunner.while acting as a dive bomber is bad. Ask the French and the Soviets.

 

[RCAFson]

Blackburn Skua, one 905 HP at 6,000 feet air cooled Perseus XII, span 46 feet, length 35 feet, height 12 feet 6 inches, wing area 319 square feet. 2 Crew wing armament 4 Browning with 600 rpg, dorsal 1 Lewis with 6 Mags. Normal and maximum bomb load 5000 pounds. RAF performance figures

Type	Type	Dive Bomber	Fighter
Weight	Tare (pounds)	5,839​	5,839​
Normal	Weight (pounds)	8,215​	8,115​
Normal	Take Off (Over 50 ft) (Yards)	670​	650​
Normal	Climb to Height (feet)	15,000​	15,000​
Normal	Climb to Height Time (Mins)	22​	21​
Normal	Service Ceiling (Feet)	19,000​	19,300​
Normal	Maximum Speed (m.p.h)	212​	213​
Normal	Max Speed Height (Feet)	15,000​	15,000​
Normal	Cruising Speed (m.p.h)	193​	194​
Normal	Cruise Speed Height	15,000​	15,000​
Normal	Bomb Load (pounds)	500​
Normal	50 Minutes allowance Range (miles)	466​	906​
Normal	50 Minutes allowance Endurance Hours	2.93​	4.67​
Normal	Fuel (for range, pounds)	706​	1,080​
Normal	Fuel (for allowance, pounds)	142​	142​
Normal	Fuel (Total, pounds)	848​	1,222​
Normal	Fuel (Total, Gallons)	163​	163​
Normal	Miles per 100 pounds fuel	80.2​	83.9​
Extended	Overload Weight (pounds) (Max bombs (or Fuel if same))	8,625​	8,115​
Extended	Take Off (Over 50 ft) (Yards)	770​	650​
Extended	Climb to Height (feet)	15,000​	15,000​
Extended	Climb to Height Time (mins)	25​	21​
Extended	Service Ceiling	18,000​	19,300​
Extended	For Maximum Bombs (Cruise)
Extended	Speed (m.p.h)	190​
Extended	Height (feet)	15,000​
Extended	Bomb Load (pounds)	500​
Extended	Range (50 mins allow.) (miles)	890​
Extended	Endurance (50 mins allow.) Hrs	4.7​
Extended	Fuel (for range, pounds)	1,080​
Extended	Fuel (for allowance, pounds)	142​
Extended	Fuel (Total, pounds)	1,222​
Extended	Fuel (Total, Gallons)	163​
Extended	Miles per 100 pounds of fuel	82.5​
Extended	For Maximum Fuel (Economical)
Extended	Speed (m.p.h)	157​	156​
Extended	Height (feet)	15,000​	15,000​
Extended	Bomb Load (pounds)	500​
Extended	Range (50 mins allow.) (miles)	980​	1,025​
Extended	Endurance (50 mins allow.) Hrs	6.25​	6.57​
Extended	Fuel (for range, pounds)	1,080​	1,080​
Extended	Fuel (for allowance, pounds)	142​	142​
Extended	Fuel (Total, pounds)	1,222​	1,222​
Extended	Fuel (Total, Gallons)	163​	163​
Extended	Miles per 100 pounds of fuel	91​	95​

The Skua specs above are not at FTH (max boost) which was:
(3) Maximum level flight (5 minute limit) rpm 2,750 Boost +2½lb/in2 which could be held till about 7000ft. (static 905 hp at 6500ft). (From Smith).

 

[planespotting]

First up, thanks to several of you for some actual performance figures for the Skua...

Spec O.27/34 that led to the Skua called for max speed 225mph at 6,500 feet.

"Wings of the Navy" by Eric Brown gives Skua speeds as follows:-
225mph max at 6,700 feet
204mph at sea level

"British Naval Aircraft since 1912"
225mph max at 6,500 feet
204mph at sea level

"Blackburn Skua & Roc" by Matthew Willis gives Skua speeds as follows:-
225mph max at 6,500 feet

"British Carrier Aviation" by Friedman
225mph (196 knots) max at 6,700 feet
204mph (177 knots) at sea level

Friedmaan uses the same figures in "Fighters over the Fleet" but with the following added comment:-
"In 1934, estimated maximum speed with a Perseus IIS engine (835hp at 15,000ft) was 203 knots [233mph] at 15,000ft. with a service ceiling of 30,000ft ...."

Blackburn Skua, one 905 HP at 6,000 feet air cooled Perseus XII, span 46 feet, length 35 feet, height 12 feet 6 inches, wing area 319 square feet. 2 Crew wing armament 4 Browning with 600 rpg, dorsal 1 Lewis with 6 Mags. Normal and maximum bomb load 5000 pounds. RAF performance figures

Type	Type	Dive Bomber	Fighter
Weight	Tare (pounds)	5,839​	5,839​
Normal	Weight (pounds)	8,215​	8,115​
Normal	Take Off (Over 50 ft) (Yards)	670​	650​
Normal	Climb to Height (feet)	15,000​	15,000​
Normal	Climb to Height Time (Mins)	22​	21​
Normal	Service Ceiling (Feet)	19,000​	19,300​
Normal	Maximum Speed (m.p.h)	212​	213​
Normal	Max Speed Height (Feet)	15,000​	15,000​
Normal	Cruising Speed (m.p.h)	193​	194​
Normal	Cruise Speed Height	15,000​	15,000​
Normal	Bomb Load (pounds)	500​
Normal	50 Minutes allowance Range (miles)	466​	906​
Normal	50 Minutes allowance Endurance Hours	2.93​	4.67​
Normal	Fuel (for range, pounds)	706​	1,080​
Normal	Fuel (for allowance, pounds)	142​	142​
Normal	Fuel (Total, pounds)	848​	1,222​
Normal	Fuel (Total, Gallons)	163​	163​
Normal	Miles per 100 pounds fuel	80.2​	83.9​
Extended	Overload Weight (pounds) (Max bombs (or Fuel if same))	8,625​	8,115​
Extended	Take Off (Over 50 ft) (Yards)	770​	650​
Extended	Climb to Height (feet)	15,000​	15,000​
Extended	Climb to Height Time (mins)	25​	21​
Extended	Service Ceiling	18,000​	19,300​
Extended	For Maximum Bombs (Cruise)
Extended	Speed (m.p.h)	190​
Extended	Height (feet)	15,000​
Extended	Bomb Load (pounds)	500​
Extended	Range (50 mins allow.) (miles)	890​
Extended	Endurance (50 mins allow.) Hrs	4.7​
Extended	Fuel (for range, pounds)	1,080​
Extended	Fuel (for allowance, pounds)	142​
Extended	Fuel (Total, pounds)	1,222​
Extended	Fuel (Total, Gallons)	163​
Extended	Miles per 100 pounds of fuel	82.5​
Extended	For Maximum Fuel (Economical)
Extended	Speed (m.p.h)	157​	156​
Extended	Height (feet)	15,000​	15,000​
Extended	Bomb Load (pounds)	500​
Extended	Range (50 mins allow.) (miles)	980​	1,025​
Extended	Endurance (50 mins allow.) Hrs	6.25​	6.57​
Extended	Fuel (for range, pounds)	1,080​	1,080​
Extended	Fuel (for allowance, pounds)	142​	142​
Extended	Fuel (Total, pounds)	1,222​	1,222​
Extended	Fuel (Total, Gallons)	163​	163​
Extended	Miles per 100 pounds of fuel	91​	95​

So (and correct me if I misunderstand), what this says when it's taken together is that the 1934 specifcation called for 225mph at 6,500ft, that the resulting 1934 design speed was 203 mph at 15,000ft with a Perseus IIS, that most sources quote the specification speed, sometimes hefting the altitude by 200ft, but that a detailed legend raises the slower design speed by a round 10mph to 213 mph with the Perseus XII (still, rather oddly, at 15,000ft rather than its own rated altitude of 6,500ft)?

Are those figures likely to be accurate, or are they just estimates created by tinkering with 1934 numbers? Was the Skua, in fact, slower than advertised? Anyone know where 204 mph at sea level comes from? Or 6,700ft rather than 6,500ft?

The Skua specs above are not at FTH (max boost) which was:
(3) Maximum level flight (5 minute limit) rpm 2,750 Boost +2½lb/in2 which could be held till about 7000ft. (static 905 hp at 6500ft). (From Smith).

Thanks! Do you know what that means in terms of speed, though?

No topic is too off topic. There's usually a wealth of knowledge to be gained from our little detours.

Thanks for the encouragement! I'll maybe detour back to Leyte, as it's come up in the replies, but I've left it off for now...

Welcome on board now officially registered.

Thanks too!

A related question is why the Perseus and Mercury both remained in production at the same time given that they had a very similar performance?

Anyone got any idea why?

Not as a navigator though. Normally a lowly Telegraphist Air Gunner whose main purpose was to operate the homing device that could find the carrier wherever it may have moved to. Of course a navigator could replace the TAG such as one in a strike group.

Ah! That makes sense, so it's not so much "navigating" as using his radio training - though presumably it's vulnerable to enemy RDF?

That's a bit unfair. The rear gunner in the Dauntless was also a radioman-gunner and not a navigator. Everyone at the time thought a rear gunner was necessary for dive bomber.

I'd assumed as much simply from its prevalence, but then something like the Fulmar trades the rear gun for moderately better performance, and that's the sort of context I'm thinking of to modify the design, if that makes sense?

But the RN expected to fight around 10,000 feet. That was seen as the ideal approach height for the torpedo bombers for which the Skua was to act as escort in one of its roles. The operational height of the Fulmar was specified in 1938 to be 10,000ft. Only with the 1939 & 1940 Specs was the operational height increased to 15,000ft.

Oh, I agree, insofar as my knowledge extends. My sense is that in the 1930s, everything was pegged to the idea of bombers trucking along at 10,000ft, so I'm not imagining that they'd be unreasonably smart/ambitious when the Skua was originally designed. No, my point about a new engine is really a question about the potential of the airframe for an upgrade circa 1939 - is it too surreal to talk about a Skua equivalent of a Griffon Spit?

USS Nevada

That is an over simplistic view of what happened to her, and just because it happened while in PH, it does not follow that the same would have happened had she been at sea. Look at the damage report.

Researcher@Large - BB-36 USS Nevada Pearl Harbor Attack Damage Report

The report makes very interesting reading - the question I now have to answer with a detailed read is whether the torpedo protection and damage-control counterflooding mitigated the torpedo hit as it was designed to (and as I had assumed it had); in short would the less controllable flooding from the bomb hits and the associated problems of uncontrolled fires and the engines being knocked out for about ninety minutes have sunk her without the torp? One thing that's clear (paragraphs 89 and 91) is that the technically-unnecessary flooding of the aft magazine after the torpedo hit had the unintended consequence of reducing the effect of the bomb damage, by lifting the forepart of the ship higher out of the water...

I also appreciate the report's direct confirmation of something else I'd suspected, namely that the (comparatively slight) damage to the dry-docked USS Pennsylvania and the destruction of the adjacent destroyers was also the work of the Vals, not the first wave's level-bombing...

HMS Warspite
The story is not as simple as you lay it out.

I'd say it's more that I simplified the phrasing - I was broadly aware that the damage to Warspite was above decks, my point is that it was still enough damage to take a fast battleship out of the fight for ten months. The fact that it was just one 500lb hit only reinforces that point.

Funnily enough there has been a discussion on another site about GZ and her air group. By May 1941 any connection with GZ it is to say the least tenuous given the turnover in aircrew that would have occurred in Luftwaffe units as a result of losses in the BoB. Here is the history as posted of the II./186(T) that became III./JG77 that was reponsible for the bombing of Warspite.

My understanding is that at least one staffel of III./JG77 remained a dedicated anti-shipping dive-bomber unit carrying over the skills of II./186(T), they skipped the Battle of Britain (perhaps specifically for that reason?), and at least the gruppenkommandeur and the staffelkapitän were veterans of the original unit, implying some ability to pass on tactics and training...

Kurt Ubben - Wikipedia

en.wikipedia.org

Wolf-Dietrich Huy - Wikipedia

en.wikipedia.org

The Whirwind was modified to drop 2x250lb or 2x500lb bombs from Aug 1942 in the fighter bomber role. But I don't believe it was ever used as an 80 degree dive bomber.

That's certainly what's claimed in Niall Corduroy's book on the Whirlwind, and I think it's stated in a squadron war diary online somewhere, too. Used against the FW 190 runway at Maupertus and the blockade runner Münsterland, apparently, though 250lb GP bombs were probably not ideal...

This will explain the Whirlwind's propellor problems.

The Westland Whirlwind British fighter aircraft of WW2

dingeraviation.net

I'm aware of the argument about blade-shape, which would presumably make a difference, but it also seems that the production aircraft were stuck with variable-pitch propellers rather than constant-speed ones, and that would have surely had an effect, comparable to what was seen with the Spitfire or Hurricane...?

It was April 1943 before RE Bishop of De Havilland suggested to NE Rowe of MAP that it might be possible to modify the Mosquito to carry a 4,000lb Cookie. Authorisation for a trial conversion of a Mk.IV was given on 29th April 1943. That aircraft DZ594 flew in July in its new form. The first converted aircraft were delivered to 692 squadron in Feb 1944 and flew their first missions on 23rd Feb.

Apologies for not being entirely clear - my reference to de Havilland doing things in 1940 was to the origins of the Mosquito in general, not its use as a cookie jar, which as you say came later.

Not sure where you got the idea that the Pathfinder force wasn't telling anyone what they were doing. Harris authorised it all after all.

I had the sense that Bomber Command understood the "nuisance bombing" remit in a more literal sense than Pathfinder Force. But I could be quite wrong there...

USS Nevada was torpedoed between her forward turrets before getting underway, then ordered to stop as it became clear to local command the Japanese were trying to sink her in the habour channel, something that would bottle up the fleet. Total of 5 bomb hits, plus torpedo plus delberate flooding of the magazines plus counterflooding to correct the torpedo induced list pushed the waterline above the highest water tight deck. The USN commented on the effects of near misses when repairing Illustrious. Warspite, damaged 22 May 1941, arrived in the US for repairs 11 August (via the Pacific) recommissioned 28 December.

I've commented on this at more length above, in response to the detailed report that EwenS linked...

The Whirlwind was the medium altitude bomber destroyer, the Welkin the high altitude interceptor. The Whirlwind was adapted as a fighter bomber, which operations used 80 degree dives? The wing cells in the Fairey Battle could release their bombs safely in an 85 degree dive.

Again, commented on above. The Whirlwind was "high altitude" by 1930s standards in terms of being designed to intercept at 15,000ft, rather than 10,000ft, though I can see why that's a confusing turn of phrase...

And I thought that while the Battle could theoretically bomb at a steep angle, the airframe wasn't actually able to get there?

(Tail less bombs) Quite sure, consider how easy it is to see bombs falling at night. And it was the USSBS post war including examination of the dud bomb dumps. The US proved quite conclusively heavier bombs were more accurate.

Do you know if the source material with the German comments is available anywhere, out of interest?

As for the majority of aircraft, having the Merlin is an upgrade. Big 2-row radials of 2000 lbs might be a bit too much of a good thing.
Taurus being small is/was a good thing, what was not good was that Taurus on itself was never considered as a win, and required 100 oct fuel to make about 1100 HP, despite being a spanking new design. Installing a Pegasus would've been improvement over the Perseus, IMO.
G&R Mistral Major as made at Alvis (the 'Pelides') was not with a high-altitude S/C, rated altitude was at 7500 ft, where 975 HP was produced.

I don't know why I thought the Alvis was high-altitude, but I hadn't realised that the Pegasus was improved to the extent it was - you're probably right, in that case!

Backseater has it's role in the FAA in the late 1930s-early 1940s, not just to operate the homing device.

Equaling Gladiator and Fulmar wrt. speed might be done with a Merlin X on board. Equaling Sea Hurricane - not likely. Keeping the Skua firmly in the dive bombing role would've been the best, IMO, and provide some meaningful fighter escort in the meantime.

What, Fulmars?

Obviously, designing a dedicated single-seat carrier fighter would have been the right solution, but as someone said further back in the discussion, they wanted a multi-role type because of limited hangar space... so if they'd done the sensible thing, they might have been stuck with Sea Hurricanes and Skuas and no Swordfish...

This has already been discussed, but the Telegraphist/Air Gunner was necessary for homing in on the carrier's beacon. Also, not having a tail gunner.while acting as a dive bomber is bad. Ask the French and the Soviets.

Isn't it more than attack aircraft that lack fighting qualities need a tail gunner? The question I'm asking is whether a single-seater Skua can be raised to the performance of a Gladiator or Fulmar...

But you have just led me to discover the Loire-Nieuport LN.401, the French equivalent of the Skua - it was a single-seater, had marginally better speed on a paltry 690 hp, and its attrition in 1940 was due to flak, not the lack of back-seaters...

 

[Reluctant Poster]

As mentioned, the Telegraphist/Air Gunner was necessary for homing on the carrier's beacon. The British system was not user-friendly and was eventually replaced by the American system.

Also, not having a tail gunner.while acting as a dive bomber is bad. Ask the French and the Soviets.

The Zed Baker was first tested in May 1938. The Skua was in production by that time. I don't know how you design for something that doesn't exist. The USN didn't finish equipping their F4Fs until mid 1942. Let's not forget that the Skua was out of frontline service before America entered the war.

 

[elbmc1969]

The Zed Baker was first tested in May 1938. The Skua was in production by that time. I don't know how you design for something that doesn't exist. The USN didn't finish equipping their F4Fs until mid 1942. Let's not forget that the Skua was out of frontline service before America entered the war.

?????????????????????????????????

I never said that the US system was in service when the Skua was designed.

Two statements, both true:

1. The British system was not user-friendly (based on accounts by FAA personnel)

2. The RN eventually adopted the US system

 

[RCAFson]

First up, thanks to several of you for some actual performance figures for the Skua...


So (and correct me if I misunderstand), what this says when it's taken together is that the 1934 specifcation called for 225mph at 6,500ft, that the resulting 1934 design speed was 203 mph at 15,000ft with a Perseus IIS, that most sources quote the specification speed, sometimes hefting the altitude by 200ft, but that a detailed legend raises the slower design speed by a round 10mph to 213 mph with the Perseus XII (still, rather oddly, at 15,000ft rather than its own rated altitude of 6,500ft)?

Are those figures likely to be accurate, or are they just estimates created by tinkering with 1934 numbers? Was the Skua, in fact, slower than advertised? Anyone know where 204 mph at sea level comes from? Or 6,700ft rather than 6,500ft?




Ah! That makes sense, so it's not so much "navigating" as using his radio training - though presumably it's vulnerable to enemy RDF?

Official performance spec was 225mph (196 knots) at 6700 ft with a 500lb. Performance slowly declined above that altitude.

Sometimes performance is stated without using the combat rating of the engine.

The RN Type 72 Homing beacon was designed specifically to defeat radio DF:

RN carrier homing beacon

I found this article and thought you guys might be interested. http://www.nonstopsystems.com/radio/article-part3a-1947-Quinn.pdf If you are interested in naval aviation and ever wondered what the lighthouse shaped thing on a RN WWII carrier was (top of mainmast in this pic of HMS Ark Royal)...

ww2aircraft.net