Problems with British wartime high power piston engines

[JFC Fuller]

No they don't. The Luftwaffe could still mount ops but it was in no way the force it had been twelve months earlier. And once again, this is very much the wrong thread for this.

It is a credit to the British that they focussed on an engine that was just 20% the cost of the Sabre and available as a viable combat propulsion unit in 1939, 1940, 1941 and 1942, when the Sabre wasn't, and continued to be developed beyond that.

 

[tartle]

In October 1942 a presentation to senior Staff Members of Whitehall had a trip to Derby and part of Hives's presentation to them reads:

"At the beginning of the war, we insisted that a contract we had for a new type of engine, on which we had spent four years of development, and which was fully approved, should be cancelled, in order to reduce the types in production.Last year we cancelled the production of the 2,000 hp Vulture engine, because we were certain we could make a better contribution to the R.A.F. both as regard quality and numbers, by developing the Merlin.The engine that is planned to replace the Merlin at a future date is the Griffon, which is virtually a 24% larger Merlin. It follows the same technique, so that all our manufacturing capacity is used to produce this engine."

 

[J.A.W.]

JFCF, I think your cost focus is misplaced, yes, the spending Britain put into its air power was probably excessive,
but ensuring a technological performance edge for fighter air combat is a primary requirement, at any cost, as demonstrated by the perseverance with the Sabre/Typhoon program & one directly related to this thread topic..

( & the LW were - embarrassingly - able to put nearly a thousand fighters over Allied airbases on 1-1-45..)

 

[JFC Fuller]

Force development and sustainment, of which technological edge is just a part, are the priorities. And the Merlin was demonstrably the right engine for that. The Sabre survived because Napier had nothing else to do.

Bodenplatte, the operation that required almost every Luftwaffe combat unit on the Western Front, that failed in its primary objectives and the consequences of which the Luftwaffe never recovered from. Certainly not the pre-44 Luftwaffe and still the wrong place for this discussion.

 

[J.A.W.]

Force development and sustainment, of which technological edge is just a part, are the priorities. And the Merlin was demonstrably the right engine for that. The Sabre survived because Napier had nothing else to do.

Bodenplatte, the operation that required almost every Luftwaffe combat unit on the Western Front, that failed in its primary objectives and the consequences of which the Luftwaffe never recovered from. Certainly not the pre-44 Luftwaffe and still the wrong place for this discussion.

If the Sabre had been a lame duck like the Vulture, Napier would have been given other tasks..

It was primarily - the inability of any other 'British wartime high power piston engine' to provide performance
equivalent to the Sabre, that ensured that an effort made was maintained, even over the objections of R-R..

( & I can recommend D.Caldwell's books as good info re LW ops)..

 

[JFC Fuller]

I can recommend the RAF's own official histories as good for the decline in Luftwaffe capability.

There was nothing else for Napier to do, all it had was the Sabre so it was allowed to get on with it until it became apparent the situation was so bad that EE was brought in. RR and Bristols (and their various Shadows) in the meantime turned out a combined total of over 200,000 Merlins and Hercules, with ever higher hp outputs, compared to a paltry 5000 Sabres. The Vulture was cancelled so RR could focus on the immediately available, far lower cost, and already in widespread use on multiples types- Merlin.

2,000hp Griffon engined Spitfires were in service in January 1944.

 

[tartle]

The Merlin production looks like this:

Number of Merlins manufactured= 168,040 Derby 32,377
Crewe 26,065
Glasgow 23,647
Ford, Manchester 30,484
Packard, Detroit and Continental, Muskegan 55,523

Each tooksenior engineering personnel off the main 'job'; Ellor for instance went to Packard;


the mentoring scheme Hives set up as he overhauled the personnel system in the mid thirties meant(jets) Geoff Wilde was ready and willing (many years later he mentored me!).
Fortunately RR had the numbers to cope somehow... though it shortened many a lifespan.
Bye for now

 

[robunos]

Once again, some interesting points raised here...

Regarding Bee Beamont's crash and capture, I was using the passage in his own book, 'Testing Years', where he states that 'the engine stopped'; from that turn of phrase, I took it to mean that the failure was mechanical, rather than combat damage. I haven't read the PDF linked to yet, as the computer I'm posting from refuses to open it...

As far as I can make out the main thing that held up Centaurus development was the Hercules programme which saw the type continually improved...in much the same way as the Merlin seems to have held up a lot of the Griffon development.

Hmm, the classic twin-track development dilemma. "Do we keep developing the existing type, or switch over to the new type?" Or, put more accurately, "When do we discontinue development of the old type, and change over to the new?"
In my original post, I suggested that Hercules engined types could have been up-engined with the Centaurus, paralleling the way Merlin engined Spitfires were 'Griffonised', but this seems not to have happened. I'm therefore assuming that the Hercules was adequate for the tasks required. A Centaurus Beaufighter would have been something to see, though (mind you, the Brigand was effectively this).

Just in passing, as it's really the subject for another topic, just what was so wrong with the Firebrand? It couldn't have been just that the early versions were Sabre powered?

the Buckingham was an abject failure.

I was under the impression that there was nothing technically wrong with the Buckingham, but rather the existing available US types, B-25 and B-26, were adequate for the task, so there was no point in further developing the Buckingham. I believe I'm right in thinking that the Brigand was effectively a torpedo bomber version of the Buckingham, and that seemed be okay...

If the Sabre had been a lame duck like the Vulture, Napier would have been given other tasks..

Which was what I was alluding to in my original post, switching Napier to Centaurus production...

& the British did have reasonable qualms about the suitability of radial engines for fighters..

Could you expand on this?
cheers,
Robin.

 

[JFC Fuller]

This thread is getting too diverse and most of these areas have been adequately covered elsewhere in the forum so I will keep my remarks brief.

There was little dilemma between evolution and new design, it was actually quite a simple choice. The oft-quoted example is this (from Postan), the Spitfire Mk.I took 330,000 man hours to design and develop but the subsequent 15 marks averaged just 41,000. Even the radically different and troublesome Mark XXI took 165,000 and this was the most time consuming of the Spitfire evolutions. The same applied to tooling and jigging, for the Spitfire Mark I this took 800,000 man hours but an average of just 69,000 hours for the other marks. As I remarked earlier, from specification to operational service for a wholly new type in this period was 4 years, evolutions could be done much faster.

Switching Napier over to another engine type would had a range of difficult issues. Firstly, there was only one economical Sabre factory (capable at most of 2,000 units a year) as the Acton facility had a very low capacity. Swapping this factory to a new type would probably have taken almost 12 months. The 2000 a year capacity was also relatively small beer compared to what was being achieved for other types. Also, such a move would have effectively killed Napier as an independent aeroengine design company which was considered undesirable.

The Firebrand story is far too long for here, suffice to say there were many better solutions. The Buckingham was regarded as unsuitable for combat use, the Brigand used a different fuselage and was much more successful.

 

[robunos]

JFCF, thanks for that, things are a lot clearer, now.
I've also done my homework on the airframe questions, and got that clear, too.
Should also have said, that the last two points were aimed at JAW...

cheers,
Robin.

 

[J.A.W.]

R, the Centaurus is rather larger, heavier, & more powerful than the Hercules,

Most if not all airframes that accepted the Hercules - would not accommodate a straight swap.
Perhaps the lack of viable Centaurus recipients was the reason for the low development/production priority.

Of the big 3 Brit piston engines, Centaurus, Griffon & Sabre, only a few were actually produced, & flown,
- perhaps fewer than 15,000 of all - in total.

Griffons may have striven, struggled & been pushed to get to 2,000hp, & eventually a bit more, & keep it
at altitude - due to R-R multi-stage supercharging prowess..
..but were always going to be the runt of this trio power-wise..

& given that the Centaurus was capable of a 3,000hr TBO VS ~350hr for the Griffon it is remarkable
that the Shackleton got & kept operating the R-R V12 for all those decades..
..must've been a nice little earner for R-R..

As to the suitability of radial engines in fighters, there is a fair bit about it in the '...power to fly' thread..
..but in a nut shell, the general characteristics & control systems of most radials were best suited to
efficient steady state running under the hand of a dedicated fight engineer, the needs of which could put rather
a burden on the sole operator in fighter combat & on the engine like-wise - if being abruptly/roughly handled..

In multi-engine bombers/transports, it was often the pilots job to work the only the flying controls
while the flight-engineer handled all the myriad engine fettling matters ( but together, as a team).

& JFCF,
I reiterate, while the Liverpool facility was solely built for Sabre production, if the Sabre itself
had proven itself a dud, like the Turkey, ah sorry - I mean Vulture..
.. Napier would have been kept busy with other work.

(& the RAF histories certainly show the Sabre powered Hawkers with their significant warlike superiority over the Spitfire for 2nd TAF purposes - were in the van of intense effort against the ever active Luftwaffe - right up to wars end).

 

[JFC Fuller]

As has been pointed out by multiple posters the Vulture was cancelled to allow RR to focus on the far more important Merlin- which it did with great success. Napier on the other hand kept the Sabre because it had nothing else to do and individuals within MAP wanted to keep the company in the engine design and development business.

The Typhoon made for an excellent 2TAF attack aircraft nicely making up for the chronic interwar under investment in such types, it did sterling work and rightfully deserves praise for it but the air superiority campaign, the bulk of which the Tempest missed, was won by Mustangs, Spitfires and P-47s.

 

[J.A.W.]

The Sabre, as the most powerful & most effectively utilised in wartime..
.. of the 3 big British high horsepower engines, & uniquely as a viable 'hyper'-type mill..
.. made a primary contribution to the RAF in ADGB & 2nd TAF post invasion.

( American strategic airpower via the P-51 - wrought the most significant attrition on the Luftwaffe, true).

Merlin contribution via Mustang & Mosquito was very effective..
.. but while doing ah , sterling duty in heavy bombers, the actual effective value of that role, in itself, is moot.

 

[JFC Fuller]

The Sabre was the most used of three poorly used engines- thats a great medal you just awarded. But I agree, the Typhoon units in particular were a key component of 2TAF and its primary close strike weapon.

The value of the role is not relevant to the value of the engine- and I will not rise to the bait of engaging in a long discussion of the efficacy of Bomber Command in its heavy form. Suffice to say those Merlins that powered Lancasters could equally have powered Mustangs, Spitfires or Mosquitos.

The British obviously go over their supposed (and apparently brief given their pre-war inventory) aversion to radial fighters given the mass orders for Centaurus powered Tempest IIs.

 

[J.A.W.]

The Sabre was the most used of three poorly used engines- thats a great medal you just awarded. But I agree, the Typhoon units in particular were a key component of 2TAF and its primary close strike weapon.

The value of the role is not relevant to the value of the engine- and I will not rise to the bait of engaging in a long discussion of the efficacy of Bomber Command in its heavy form. Suffice to say those Merlins that powered Lancasters could equally have powered Mustangs, Spitfires or Mosquitos.

All M/Mustangs & the most efficacious Mosquitos & Spitfires utilized the multi-stage Merlins, the Lancs didn't..

The Tempests were also the air-superiority spearhead of 2nd TAF, & while cleared to carry ordnance
for the fighter-bomber role, were very rarely tasked with that duty - unlike the Typhoon & most Spitfires..

 

[JFC Fuller]

Mosquitos consistently used essentially similar variants of the Merlin to the XX used in the Lancaster, see: http://www.flightglobal.com/pdfarchive/view/1954/1954%20-%201297.html

As pointed out previously, Tempests turned up too late for the most important work, great plane when it finally did arrive but June 1944 was cutting it fine. Spitfires were busy escorting daylight heavy raids by then as well as having responsibility for most of the medium-high altitude work.

 

[J.A.W.]

Mosquitos consistently used essentially similar variants of the Merlin to the XX used in the Lancaster, see: http://www.flightglobal.com/pdfarchive/view/1954/1954%20-%201297.html

As pointed out previously, Tempests turned up too late for the most important work, great plane when it finally did arrive but June 1944 was cutting it fine. Spitfires were busy escorting daylight heavy raids by then as well as having responsibility for most of the medium-high altitude work.

Opinions as to which 'work' is considered most important vary..

Some might argue that ADGB anti-JABO & anti-V1 duties were quite important, as the Sabre proved its worth..

Short range Spitfire coverage of initial legs of heavy bomber missions with little chance of engaging the LW,
might be regarded as make-work, by comparison..

Not so much useful high-medium altitude work going in the 2nd TAF post-invasion either..

The really good performing Mosquito types of bomber, PRU & NF used the 2-stage Merlins,
for low altitude strike/intruder sorties these were not so needful, true..

 

[J.A.W.]

One Griffon issue - which was a problematic error - was the reverse rotation to the Merlin..

An avoidable cause of many needless Spitfire take-off dramas ( & crashes).

Who was the fool who signed off on that feature - as acceptable?


Centaurus Tempests were too late for WW2, & were intended for duty against the lesser forces of Nippon,
same as RAF employment of Thunderbolts, seems the RAF never saw radial powered fighters as fit for A2A combat roles against the 109/190s, ( FAA did a bit though, & lost a Corsair - intact - to be evaluated by the LW).

 

[J.A.W.]

Here is a case in point..
- Tim Wallis had quite a few hours up in his Merlin Mk XVI Spit,
But he acquired a Griffon powered Mk XIV too.
Then one day he jumped into the XIV & took off on 'auto-pilot' ( Merlin rotation conditioning) & crashed..
Too bad he/his crew didn't have the gumption to put a prominent notice re opposite rotation trim - in the cockpit.

http://www.youtube.com/watch?v=QarkVkBiVb8

 

[J.A.W.]

& footage of Sabre & Centaurus in flight powering a couple of big Hawkers..

http://www.youtube.com/watch?v=BKq51LdJ-ZU

http://www.youtube.com/watch?v=QErxi6ixi_o

 

[JFC Fuller]

Spitfires did plenty of good medium altitude work post-invasion being the main top cover for 2TAF Typhoon operations. Remember that the 3rd Tempest Squadron was only converting in June 1944 and the total number of Squadrons available during the war only hovered around nine and didn't get there until December 1944. By contrast nine Squadrons of Spitfires provided just the outbound escort of the first Bomber Command heavy daylight raid in Homberg on the 27th August, a further 7 covering the egress.

Breaking the Luftwaffe pre-invasion was clearly more important work.

 

[J.A.W.]

"Breaking the Luftwaffe" ( actually never achieved , except by final surrender) before the invasion was done by:

A, In the case of the LW bomber force, by A. Hitler's insistence on attacking London via the 'Baby Blitz'..
&,
B, In the case of the LW fighter force, by the long-range depredations inflicted by the USAAF Mustangs..

Spitfires based in Blighty had tried 'leaning into France' since 1941- & had suffered a net loss..

Since according to pilots reports, unladen 'escort' Spitfires had difficulty keeping up with ordnance laden
Typhoons - at their Sabre-powered high cruising speed, the value of such 'high cover' is moot..

Especially since Spitfires apparently had difficulty coordinating 'high cover' - even for lumbering Lancasters..
According to D. Caldwell, on 15 July `44, a unit of JG 26 caught Lancs unattended & 5 went down..

& P.Clostermann writes that Spitfires also had plenty of (risky) employment dive-bombing V1 'ski sites'..

There were bags of Spitfires available, but not many were hi-po Griffon powered Mk XIVs, either..

 

[JFC Fuller]

Wrong thread.

Plenty of spits being available is the point, they were in production, and their airframe and engine could be evolved rapidly and were doing things that Sabre powered birds couldn't dream of. They were 2TAFs air superiority capability and the bulk of ADGB.

 

[J.A.W.]

Wrong thread.

Plenty of spits being available is the point, they were in production, and their airframe and engine could be evolved rapidly and were doing things that Sabre powered birds couldn't dream of. They were 2TAFs air superiority capability and the bulk of ADGB.

Simply wrong, JFCF.

The Sabre was the high horsepower aero-engine that provided the spearhead for the RAF in both ADGB
& 2nd TAF for A2A & A2G..

Sure, Blighty was crawling with Merlin Spitfires, but they did not offer either the performance or utility
of the Sabre powered Hawkers.

Here is what Bob Spurdle, Kiwi Spitfire ace, & C.O. of 80 sqdn in August `44, reckoned,
- when they received Tempests - to replace their Spit IXs..

"Our Tempests arrived! Brand new; shining in the sun! They seemed huge after our dainty Spitfires.
But could they go! We found they cruised almost 100mph faster than the Spits, climbed like rockets &
dived at incredible speeds...we were delighted...flying the best fighter in the Allies stable...
With over 2,400hp, the Napier Sabre motors let us outperform anything else..."

After the initial Typhoon equipped units - 486 (NZ), 3, & 56 sqdn's - had traded up to Tempests,
- it was realised that with the value of Typhoons for 2nd TAF in the forthcoming invasion ( carrying 4 cannons rather than 2 & ~x2 the ordnance, & ranging further than the Spitfires), subsequently Tempest sqdns
were per 80 sqdn, giving up their Spitfires, for the push to VE-day..

The wartime RAF never had enough Sabre engine powered planes,
or Mustangs, but by 1944, Spits were a virtual glut on the market..

 

[JFC Fuller]

Simply right.

Sabre powered Typhoons were the primary close strike component of 2TAF where they did excellent work. But all the key fighter work was done by Merlin engined types. The Tempest was barely even in service for a full year of the European war and never got over ten operation Squadrons during that time. It did good work where it was available but it was never available in sufficient numbers to be that significant. Nobody is saying it was't a great aircraft, it clearly was, but its overall contribution was relatively small.

 

[J.A.W.]

Glad you agree, JFCF..

That there were so few Sabres available - is not the fault of the machine, JFCF, however the facts speak..

From 'Air Enthusiast/48' - ' 122 Wing A Study in Air Superiority'

"The British contribution to the tactical airpower used in the invasion was the 2nd TAF.
As part of this build up, it was planned to provide a Wing of what were seen as the most effective
fighter aircraft available to the British at that time, the Hawker Tempest V."

After the V1 assault had abated, allowing the valuable Tempests to be released to 2nd TAF late in Sept `44,
they replaced the Merlin Mustangs in 122 Wing..

"This was the start of an amazing six months of intense activity for the Tempest Wing, during which they
inflicted enormous damage on the German forces & suffered severe losses themselves.
The Luftwaffe's reaction to the landings in France had been limited, but as the Allied forces advanced to the borders of Germany they were forced to react strongly to defend their homeland.
The 2nd TAF now had 5 squadrons of the most advanced fighter aircraft available based close to the front line of the Allied forces."

& as P. Clostermann put it, the task of the Tempests was..

"1, Neutralisation of the German fighters, especially the jets."

The RAF had taken on small numbers of the new gen turbo jets themselves, but they weren't up to doing this..

 

[JFC Fuller]

Yup, absolutely facts speak for themselves. Just five squadrons- not a significant factor.

And actually, the engine being five times more expensive than the Merlin and not viable as a propulsion plant until well into 1942 was key to there not being many of them.

 

[J.A.W.]

Monetary costs didn't come into it, when air superiority was at stake.. not a significant factor..

Albeit R-R took business very seriously, indeed..

Further Spitfire squadrons re-equipped with Tempests as they became available,
Since as P. Clostermann wrote,

"The Spitfires were powerless. There was only one Wing of 3 Spitfire XIV squadrons & the rest were were equipped with Spit IX or XVIs...in any case the all the Spit IX squadrons operated most of the time as fighter-bombers. ... the poor Spits had neither the speed nor the range to force the new German fighters to fight."

It is clear that one of the key thread issues..
- problems with British high horsepower piston engines -
..was the relative lack of them..

 

[J.A.W.]

Some cogent R. Beamont comments on Tempest 2nd TAF combat flying..

"In wide-ranging low-level strikes a maximum cruising speed of 365mph IAS coupled with superbly precise
controls facilitated target area penetration & with accurate gun aiming...
...superior all-round & attack vision...the Tempest began to set new standards for these ops...
...provided the pilot with the most favourable conditions for ground attack,
& for air-to-air combat experienced until then...resulted in a high success rate/low loss ratio...
...had established themselves as the most formidable low & medium altitude British fighters & the most capable type of all against the flying bomb...
...& also the general ease of operation of this big, powerful fighter which had a relatively low accident rate...
...the Tempest was less critical to land in crosswinds or turbulence than the Spitfire..."

Seems it was too bad - that so few were available, being more than worth their weight/cost in Merlin Spits..

 

[J.A.W.]

Another Kiwi ace Warren Schrader reckoned..

"...the Spitfire was quite a delicate thing really...whereas...the Tempest was a brute force aeroplane - a great big
aeroplane with a great big engine...for its size it was exceptionally manoeuvrable...fast rate of roll...
...of course the Tempest with its better performance...was a great advantage...& ...our armament
- the 4 cannon...it was an excellent gun platform..."

Although Schrader appreciated & took to the warlike advantages of the big Hawker machine,
- having requested transfer to them, the wee Spit remained his favourite..

"I preferred the Spitfire...it was a much more pleasant aircraft to fly."

 

[JFC Fuller]

Nothing there to suggest any particular contribution from the Tempest in terms of air superiority. Their number simply didn't allow it. Ah well, at least all those Merlin types and Thunderbolts had decimated the Luftwaffe before the Tempest even got to shoot something down.

And costs absolutely came into it.

 

[alertken]

the relative lack of them. Quite. The reasons were neither a Spitfire mafia, nor RR politico-business clout. M.M.Postan, (Br) Official History, War Production, P.167: "Peregrine, Vulture, Sabre, Hercules VI, Centaurus, Griffon are outstanding examples of (hopes) disappointed or deferred". MAP in US 11/42 were humiliated visiting the “British Wing” of P&W/Hartford, 1938 £-funded, now filled with R-2800 Double Wasp, and at Curtiss-Wright viewing R-3350 Duplex Cyclone. UK was slow in Big Power. But so we were in Big airframes. None of the Super schemes to follow 1936 4-motors saw Service. Why?

Well...the boys (and girls) done good to do what they did. No bombs fell on Connecticut. No torpedos impeded materiel delivery.

Do we need to prolong a spat, Merlin v.Sabre?

 

[J.A.W.]

Nothing there to suggest any particular contribution from the Tempest in terms of air superiority. Their number simply didn't allow it. Ah well, at least all those Merlin types and Thunderbolts had decimated the Luftwaffe before the Tempest even got to shoot something down.

And costs absolutely came into it.

Thunderbolts, despite being optimised & turbo-boosted for high altitude performance proved to be ineffective
compared to the Mustang ( which was ~1/2 as pricey) in the prime escort/strategic fighter duty - so, all but 1 unit ( 56th FG kept 'em for political & developmental reasons) were dropped from the glamour 8th AF air-superiority role & relegated to 9th AF tactical duties, although heavy & not at their best performance-wise at low altitudes..
~ 1,500 were lost between D-day & VE-day on costly A2G ops..

Yes - the Merlin Mustang did perform an exceptional role in decimating the LW`44/5, but Spitfires did not,
& Lancasters were (sadly) dropping thousands of Merlins on to Germany along with bombs, sometimes
over 300 a night..

The LW, despite all the pressures of the crushing Allied strength, maintained ops right up to the surrender,
inflicting losses - quite creditable under the circumstances, & left thousands of intact aircraft to be 'neutralised'
by the RAF disarmament teams post war..

The Tempest units more than carried their weight & justified their cost..

 

[J.A.W.]

A relative comparison of air superiority effectiveness can be seen in two NZ fighter squadrons viz 485 & 486..

485 flew Spitfire ops from Blighty beginning in March ' 41, they were credited with 63 E/A destroyed.

486 flew Tempest ops from May `44, they were credited with ~240 V1s & 59 E/A destroyed.

485 were due to transition to Tempests in 1945, but unfortunately there were not enough to go around..

 

[JFC Fuller]

ken,

Precisely, the War for Britain started in September 1939 when Mk.I Spitfires were being delivered with two blade propellers and the Hurricanes .303s froze at medium and high altitudes. It was more than two-years before Pearl Harbour. Hence my mentioning of the Whirlwind earlier, in 1940 the RAF needed mature types in volume and the Spitfire was the only aircraft that met the requirement. The die was really cast before the war even started, in April 1939, when CBAF got the 1,000 Spitfire order which would have been Whirlwind if Westlands could have made it work earlier.

JAW,

The Luftwaffe was a shadow of its former self post invasion, its a credit to its ground crews and pilots that it kept up ops but Bodenplatte was a last spasm not an indication of strength. 2TAF alone had 13 Squadrons of Spitfires and six of Mustangs on D-Day whilst the Tempest never even made it over 10 Squadrons during hostilities. ADGB Spitfire squadrons undertook large scale escort missions in support of bomber operations.

 

[J.A.W.]

JFCF, I suggest you check the LW ops record, since in fact due to their poor performance against the 8th AF,
their fighter units in the west were redirected to attack the fighter-bombers of the Allied tactical air forces..

I could post an order of battle that shows that more LW fighters were available in 1945 than in 1940..
(& I must remark that simply repeating erroneous assumptions - in lieu of data - adds no value to a thread)..

 

[JFC Fuller]

JAW,

A comparison of 1944/5 to 1943 would be far more useful. Also, simple availability of aircraft tells us little. How many sorties could they generate and how many hours did the average pilot have also need consideration not to mention the relative growth of the Allied Air Forces. Anyway, that is not even relevant to this thread.

 

[J.A.W.]

True, - however what is relevant - is the curious circumstance regarding the Merlin.

The USAAF found the excellent performance balance of the 2-stage Merlin & Mustang airframe
so effective - that its own indigenous (& expensive, albeit - not that a purchase price appears a primary factor) high horsepower big piston fighters were outmatched.
The Mosquito similarly, was the other performance standout Merlin powered aircraft.

& while by 1943,
- the Merlin Spitfire had (apart from 150 grade fuel/boost increases, but that applied to all piston engines ) reached a performance zenith, so the relatively few available Typhoons & Tempests ( & Griffon Spitfires, although few, also) had to step up - to meet the belated improvements shown by both piston & the new jet aircraft fielded by the LW, in the last year of the war.

 

[JFC Fuller]

Not really, The Typhoons were turned into CAS assets and the Tempests only existed in small numbers (ten squadrons being the wartime peak). Meanwhile Griffon spitfire squadrons were also standing up and the Merlin powered Spitfires still provided the top cover for the 2TAF bombers and escort for Bomber command heavies.

 

[J.A.W.]

As previously noted, the Tempest Wings ( along with Spit XIV units) were the 2nd TAFs primary A2A outfits.

The RAF Merlin Mustangs were the primary escort fighters, since they had the range/endurance.

The Merlin Spitfires, as noted by P. Clostermann were largely pressed into the fighter bomber role,
though of course, retained their A2A capabilities should the opportunity arise.

However the LW was under orders not to seek air-combat with Allied fighters except where tactical
advantage (numbers, altitude, location, surprise) held, & even causing jettison of ordnance was
considered a worthwhile feat.

The high performance Tempest attributes - as listed in previous posts - allowed a better prospect of
a positive outcome in A2A action, although they often fought in circumstances that met the LW conditions
'rules of engagement'-wise.

The LW particularly rated the ordnance laden, poor low level performance tactical P-47 units as juicy targets.
The Sabre engine allowed the Hawker pilots a significant power/performance characteristics advantage by
comparison, which is why the RAF chose not to operate its Thunderbolts in the 2nd TAF..

On this site - http://www.SpitfirevsBf109.com - D. Isby kindly provides some interesting wartime reports..

..including USAAF interrogations of captured LW fighter pilots who give their views of the matter..