Spitfires. How good/bad at ground attack

[Greyman]

Spitfire pilot on the subject:

Increasing evidence began to accumulate that Hitler's threat of devastating secret weapons was not an idle one. Along the French, Belgian and Dutch coasts the Germans were building rectangular cement ramps, and they were all pointed at London. Intense aerial surveillance by our PRU aircraft indicated that these structures were designed to launch something. A technique was devised to use Spitfires as dive bombers, and a directive describing it was sent out.

The target was to be approached at eight thousand feet. When it was opposite the wing tip, the aircraft was to be turned and dived at an angle of sixty degrees holding the bead of the gun-sight on the target. At three thousand feet a gradual pull-out was to be executed and on the count of three, the bomb dropped. As a footnote to the instructions, a word of caution was included. The bomb should not be released in the dive, only in the pull-out, lest it should hit the prop and blow you all to hell. Norm Fowlow, one of my former pilots in the Wolf Squadron was given command of a squadron of his own. While leading his men on a dive-bombing attack on the launching pads, his aircraft was seen to disintegrate. It was assumed that his bomb must have hit the prop.

It wasn't long before we discovered that this technique of dive bombing was extremely inaccurate. One could only take a guess at what was a sixty-degree dive. Without dive brakes, Spitfires dived so fast that the hands of the altimeter went around in a blur. Pulling out at exactly three thousand feet with the use of an instrument that lagged was impossible.

Squadrons went out individually, twelve aircraft at a time. I took my turn leading these sorties, and on one occasion I led my old outfit. I was told to bring the bombs back if I found the target obscured by cloud. The tail of the bomb was approximately an inch from the ground on takeoff or landing. In spite of the experts' assurance that the bomb would not explode unless the arming switch had been pressed, none of the pilots were anxious to see what would happen if it fell off. I dutifully read this order with tongue in cheek. I hadn't the slightest intention of bringing the bombs back.

As we approached the target twenty miles away, I could see that it was obscured by a cloud. We were flying up the Somme, and we were welcomed by a furious barrage of heavy flak. Looking down, I saw a large round heavy gun emplacement emitting a series of flashes from its eighty-eight millimetre gun.

'Echelon port!'

Instantly the Squadron slid underneath me and stationed themselves on my port wing.

'Press arming switches and prepare to attack!'

When the bunker was opposite my starboard wingtip, I rolled over and went straight down. There was nothing I could think that deserved a bombing more than a flak battery. I pulled out as close as I could to three thousand feet and on the count of three dropped the bomb. When I cocked my starboard wing up, I was just in time to see my bomb explode in the centre of the bunker. The rest of the Squadron's bombs hit all around it. The flak ceased. I ordered the Squadron to regroup and was relieved to count twelve aircraft. As we flew home, a voice on the R/T/ said:

'Sheer unadulterated bullshit luck, Skipper!'

I maintained a discreet silence.

 

[Reluctant Poster]

While its great fun to mock the Spitfire the reality is that even dedicated dive bombers had difficulty hitting small targets. The following excerpts from the attached paper illustrate this:

It would be interesting to see how accurate the P-47 was as a bomber.

 

[Reluctant Poster]

There's extensive writing about the LF.IX variants in Morgan and Shacklady's Spitfire bible, which goes into how an attack went, which I'd like to add, but don't have time as I'm about to go out, nonetheless, the LF.IX came about after Coningham in North Africa requested LF.V Spitfires as in his words 80 percent of operations were conducted at low altitude, therefore Supermarine believed that the Vs should be converted to IXs and thus trials were carried out at Boscombe with MJ823. There is more in the book about those specific trials as well as a couple of recollections of the 'Bombfires' in action from guys who flew them.

The LF IX had nothing to do with Coningham or the LF V. It was in fact the standard production version of the IX comprising 70% of total production. It was originally called the IXB and only became known as the LF IX after the introduction of the HF IX In late 1943. Shortly after the IX was introduced in 1942 Rolls Royce had developed a much improved supercharger (I described the improvements in a previous post on the Packard Merlin). Testing of the FW190 vs the original IX showed the 190 was evenly matched with the IX at 21,000 feet and lower but was way behind above that altitude. The new supercharger increased the high altitude performance even further which was pointless. The decision was made to lower the supercharger gear ratios to vastly improve the low altitude performance while keeping the high altitude performance nearly to the same level as the original IX. Thus the Merlin 66 was born. The LF IXs performance at 30,000 feet was a match for the majority of WWII fighters In fact the USSR used their LFIXs (they received over a 1000) as their standard high altitude interceptor until 1949. In 1944 Rolls Royce produced a version of 66 with the original gear ratios called the Merlin 70 which powered the HF IX. onl 400 HF IXs were produced.

Alfred Price devotes a chapter to this in his book Spitfire In Combat.
Packare did the same thing with the gear ratios when they switched from the V1650-3 to the V1650-7

 

[nuuumannn]

The LF IX had nothing to do with Coningham or the LF V. It was in fact the standard production version of the IX comprising 70% of total production.

You might have missed the point. I'm not suggesting he was responsible for the LF.IX's development, but Coningham instigated the use of Spitfires at low-level. The IX, which, you'll recall from Price's book was intended as an interim only, which was by putting 60 Series Merlins into Mk.V airframes until production of the Mk.VIII was standardised as the next major Spitfire variant. That it didn't happen that way was simply due to expediency and the use of Mk.V airframes on the production line. As the V was simply a II with a Merlin 45, so the IX was a V with a 60 Series Merlin and the XIV was a Mk.VIII with a 60 Series Griffon. But back to the low-level Mk.IXs, of course, Coningham had something to do with them as he was C-in-C of the 2nd Tactical Air Force which operated the type and prior to it, he had instigated the Mk.V low level fighter with a cropped supercharger.

 

[Geoffrey Sinclair]

The Ministry of Aircraft Production February 1943 report has the following Spitfire types being produced PR.IV, PR.XI, Vc, VII, VIII, IX and XII

The March report has PR.XI, F.Vc, F.VII, F.VIII, F.IX and F.XII

The April report has PR.XI, F.Vc, F.VII, HF.VII, F.VIII, LF.VIII, F.IX, LF.IX and F.XII

The first HF.IX were produced in March 1944, the first HF.VIII in May 1944.

 

[Reluctant Poster]

You might have missed the point. I'm not suggesting he was responsible for the LF.IX's development, but Coningham instigated the use of Spitfires at low-level. The IX, which, you'll recall from Price's book was intended as an interim only, which was by putting 60 Series Merlins into Mk.V airframes until production of the Mk.VIII was standardised as the next major Spitfire variant. That it didn't happen that way was simply due to expediency and the use of Mk.V airframes on the production line. As the V was simply a II with a Merlin 45, so the IX was a V with a 60 Series Merlin and the XIV was a Mk.VIII with a 60 Series Griffon. But back to the low-level Mk.IXs, of course, Coningham had something to do with them as he was C-in-C of the 2nd Tactical Air Force which operated the type and prior to it, he had instigated the Mk.V low level fighter with a cropped supercharger.

The point I am making is that the LF IX was not a specialized low level fighter . It was the RAF standard all purpose fighter from 1943 on.
The impeller of the Merlin 66 was not cropped, it was operated at a lower RPM.
I don't have the exact date the LF V first appeared, but it seems the Merlin 66 was already in existence at that time.

 

[Geoffrey Sinclair]

LF.V reported to have used the Merlin 45M, 50M and 55M. No official production of the Merlin 45M or 50M, 55M production from June 1943 to November 1944, 1,428 built. Merlin 66 production February 1943 to October 1944, 2,962 built.

ADFU apparently made the first clipped wing Spitfire AA937 and flew it on 2 October 1942. In November Supermarine was asked to produce 20 sets of parts to enable 91 Squadron mark V to have clipped wings. Seems a clipped wing mark XII was tested in October. Morgan and Shacklady note AB167 with Merlin 45M under test in May 1943. The online Spitfire listings have few 50M or 55M but plenty of 45M, many in aircraft that were built in 1941, which would be the older airframes reported fitted with the new engine.

Air 22/216, Fighter Command 28 May 1943 weekly strength return, Initial Equipment 1,338, strength 1,780 aircraft.

47 Spitfire Squadrons, 752 initial equipment (47 times 16), 747 serviceable, 1,254 pilots of which 1,021 operational. Comments on aircraft strength, Mark Vb down 60 (469 to 460, yes 460, the totals say it should be 409), 3 squadrons transferred to LF.Vb, LF.Vb strength up 60 (0 to 60), mark V LR up 1 (202 to 203), mark VI down 3 (34 to 31), mark VII no change (7), mark IX down 5 (126 to 121), LF.IX up 1 (20 to 21), mark XII down 1 (37 to 36), total down 7 (895 to 888).

There are no LF.IX in the 21 May report, so no indication when they arrived, there were simply 146 mark IX. Supermarine built a batch of 40 LF.IX February to June 1943, Castle Bromwich built 1 in April, 1 in June then 153 in August, production continuing until August 1945, the last F.IX was built in October 1943.

 

[A.G. Williams]

View attachment 640379

I am puzzled by the comments about daylight firing of V-weapons being more accurate. The internal guidance system for these weapons was set on the ground, and I see no reason for the accuracy varying whatever the time of day (or night).

 

[pbehn]

I am puzzled by the comments about daylight firing of V-weapons being more accurate. The internal guidance system for these weapons was set on the ground, and I see no reason for the accuracy varying whatever the time of day (or night).

It mentions rockets, maybe they are including air launched V1s which were and are frequently called rockets. The last V1 to fall on UK was on 29 March 1945 in Suffolk.

 

[nuuumannn]

The point I am making is that the LF IX was not a specialized low level fighter . It was the RAF standard all purpose fighter from 1943 on.

Actually, you're slightly wrong about that, because the LF.IX was the low altitude variant of the F.IX, which was yada yada... the LF prefix indicating its low altitude chops, which I used in my previous post.

 

[nuuumannn]

I don't have the exact date the LF V first appeared, but it seems the Merlin 66 was already in existence at that time.

The 60 series Merlin was originally built for fitting to the high altitude pressurised variant of the Wellington Bomber, the Mk. VI and as legend has it, it was Ernest Hives of RR who asked if one could be fitted to a Spitfire.

The first 60 series Merlin was fitted to a Spitfire, the Mk.III prototype in March 1941, with the first Mk.V converted with clipped wings for the low altitude role in the Middle East, as per Coningham's request was in May 1941.

 

[pbehn]

The 60 series Merlin was originally built for fitting to the high altitude pressurised variant of the Wellington Bomber, the Mk. VI and as legend has it, it was Ernest Hives of RR who asked if one could be fitted to a Spitfire.

The first 60 series Merlin was fitted to a Spitfire, the Mk.III prototype in March 1941, with the first Mk.V converted with clipped wings for the low altitude role in the Middle East, as per Coningham's request was in May 1941.

From the early days of the high altitude Wellington a turbo charger was discounted because of the issues of fitting it into a Spitfire.
Second page middle column discusses this.

http://wwiiaircraftperformance.org/merlin-lovesey.pdf

 

[Mike Williams]

There are no LF.IX in the 21 May report, so no indication when they arrived, there were simply 146 mark IX. Supermarine built a batch of 40 LF.IX February to June 1943, Castle Bromwich built 1 in April, 1 in June then 153 in August, production continuing until August 1945, the last F.IX was built in October 1943.

611 Squadron converted to LF.IX in March 1943. Rolls-Royce was installing Merlin 66 in Spitfire V airframes around that time frame. See also Al Deere's book.

 

[Vincenzo]

611 Squadron converted to LF.IX in March 1943. Rolls-Royce was installing Merlin 66 in Spitfire V airframes around that time frame. See also Al Deere's book.

They hope to convert to LF.IX, but from that source we don't know this

 

[Mike Williams]

They hope to convert to LF.IX, but from that source we don't know this

I know from 611 Squadron's ORB Form 541 that they did convert to Spitfire LF IXs and flew them operationally during March 1943. Check the aircraft serial numbers against their Form 78s held at IWM. See also 611's April ORB Form 541 for supporting documentation. As previously mentioned refer to Al Deer's comments in his book Nine Lives (see attachment).

 

[nuuumannn]

From the early days of the high altitude Wellington a turbo charger was discounted because of the issues of fitting it into a Spitfire.

They fitted turbosuperchargers to the Wellington V powered by Hercules' but not the VI powered by the high altitude Merlins.

 

[Reluctant Poster]

Actually, you're slightly wrong about that, because the LF.IX was the low altitude variant of the F.IX, which was yada yada... the LF prefix indicating its low altitude chops, which I used in my previous post.

No it wasn't. It replaced the F IX in production. In fact it was virtually the only model produced from mid 1943 to to the end of the war. As Alfred Price states, it was not known as the LF IX until the HF IX appeared in 1944. As I never tire of pointing out the LF IX was nearly as fast at altitude as the F IX. The were equal at 26,000 feet with the F IX gaining an advantage of 15 mph at 28,000 feet and above . The LF IX was 30 mph faster at 23,000 feet, they meet again at 16,000 feet with the LF IX again being about 30 mph faster at 10,000 and below.
To quote Alfred Price:
"Although the LF designation implied that this version was optimized for low altitude, in fact its high altitude performance was only slightly reduced ..."
Surprisingly he does not finish the sentence with yada, yada ,yada...

Kurfurst posted this graph on this very website in 2008. The Merlin 66 absolutely dominates production

 

[Reluctant Poster]

The 60 series Merlin was originally built for fitting to the high altitude pressurised variant of the Wellington Bomber, the Mk. VI and as legend has it, it was Ernest Hives of RR who asked if one could be fitted to a Spitfire.

The first 60 series Merlin was fitted to a Spitfire, the Mk.III prototype in March 1941, with the first Mk.V converted with clipped wings for the low altitude role in the Middle East, as per Coningham's request was in May 1941.

The first MK Vs appeared in the desert in May 1942, was Coningham clairvoyant? In any case clipped do not make an LF V, a cropped supercharger does.

 

[nuuumannn]

As Alfred Price states, it was not known as the LF IX until the HF IX appeared in 1944.

Okay, but it was still the LF, which did stand for low altitude, even if it wasn't specifically. Got ya about the LF replacing the F.IX. I have Price's book and the Spitfire bible, should'a read them both more closely.

Surprisingly he does not finish the sentence with yada, yada ,yada...

I suspect you know exactly what I meant, or would you like me to clarify it especially for you?

The first MK Vs appeared in the desert in May 1942, was Coningham clairvoyant? In any case clipped do not make an LF V, a cropped supercharger does.

T'was a typo. 1 and 2 are close to each other on the keyboard.

As for the last one, both, actually, although at different times and the clipped wings appeared before the cropped supercharger. The clipped wings were first fitted (wing tips removed and faired over) to W3248 in January 1942. Morgan and Shacklady..."Prototype for the clipped winged Spitfire VB can be considered to be W3248 and this variant was developed for low altitude duties, appearing in all war theatres". The first Spitfire V fitted with a Merlin 50 with a cropped supercharger was W3228, which was trialed at Boscombe Down in April 1943, after which the engine was removed and fitted to AB167 in May 1943. It is worth mentioning that the first Spitfire modified for Malta and the Desert in mind was tested at Boscombe Down in March 1941 (this one is definitely a 1), fitted with an air filter and slipper tank, although it was a Mk.VA without clipped wings or a cropped supercharger.

 

[wuzak]

The Spitfire III also had clipped wings.