Case of too much Merlin, not enough Sabre production - a typically sad British industrial 'cock-up' - if there ever was one.
Napier engineered to pass the type tests, not for a reliable production engine, Napier quality control meant defective engines, when irrevocable decisions were made about resource allocation Napier had little to offer. English Electric helped solve the quality issues.
Ministry figures End May 1944, 331 Typhoon in Air Storage Units, including 90 deficient in equipment, another 275 airframes, total Sabre I and II stocks 1,051 of which 274 with aircraft manufacturers 52 with home commands and 738 with repairers, given the figures below most with repairers and some elsewhere would be unserviceable.
End April 1945, before the RAF in Europe began to really wind down. Typhoon 179 in Air Storage Units, including 51 deficient in equipment, plus another 134 airframes (Total airframes in store 484, including 102 Auster IV/V, 78 Whitley, 65 Master III and 30 Welkin). To date 4,506 production Sabre, including 4,366 I and II of which 17 I/II shipped overseas. There had been 914 conversions II to IIa, 1 conversion IIa to IIb, 5 conversions from III to IIIa. Stocks were Sabre I/II 92 at aircraft manufacturers, 90 at home commands, 824 at engine repairers, total 1,006 of which 136 serviceable and 870 unserviceable. (Merlin 61, 63, 64, 65, 66, 67, 68 stocks were 2,217 serviceable, 293 unserviceable).
29 November 1945, Bomber Command all Lancaster and Mosquito with a few Lincoln, Fighter Command Spitfire, Mosquito, Mustang, Tempest, Meteor, Auster, there was also 1 unserviceable Typhoon. RAF in Germany, Mitchell, Mosquito, Spitfire, Tempest, Auster, there were also 3 serviceable and 8 unserviceable Typhoon, There were 6 Tempest squadrons in Germany, while 222 squadron in Britain was converting from Tempest to Meteor. Coastal Command Liberator, Warwick, Sunderland, Beaufighter (and 1 Buckmaster), Mosquito, Spitfire, Lancaster, Halifax, Wellington plus various types, Walrus, Sea Otter, Hurricane, Meteor, Fortress. The Typhoons had been rapidly removed, last operational service in September. So end November 1945 there were 783 Typhoons in storage, 27 deficient, plus 48 airframes, Sabre I/II stocks down to 155 serviceable and 678 unserviceable, plus 17 and 4 Sabre V. It solved the Sabre numbers problem.
AVIA 15/2389 covers the sale of RAF aircraft to France in 1945/6, Spare engine prices, Merlin from 1,460 to 1,900 pounds, 2,300 Griffon, 3,180 Hercules XVII, 3,830 Hercules 100, 5,550 Sabre II, meaning 3 to 5 Merlin per Sabre, 2 to 3 Griffon. For 2 Sabre you could buy a complete Spitfire XIV with 1,400 pounds left over to put towards a spare Griffon. The engine meant a Typhoon cost 13,650 pounds.
Avia 15/950
400 Tornado built by Avro plus spare engines budgeted to cost 5,760,000 pounds "Unit cost" 14,400 pounds
300 Typhoon (I wrote Tornado originally) built by Hawker plus spare engines budgeted to cost 5,010,000 pounds "Unit cost" 16,700 pounds
Given the small physical impact Fighter Command offensive operations had in the 1941 into 1943 period beyond confirming things like the pairs system and looser formations, ditching the Sabre entirely would be a win for the RAF, given how much more it cost to buy and maintain, developing or importing by 1943 another engine that could develop around 2,000 HP., while doing a Typhoon redesign to thin wings. After all maybe up to a quarter of Typhoon production to mid 1943 was reduced to spares due to a lack of engines anyway.
The USAAF noted the Merlin was more expensive, including maintenance, compared to the Allison but the Merlin's advantages were worth it, not so the Sabre.
Hurricanes were a death trap in the ETO, by 1942, & Spitfire Vs were not far behind. Clostermann correctly stated these facts,
I can assure you though Biggles did not fly many Hurricanes, he did fly Spitfires while noting the Bf109 could have better or worse performance depending on the models chosen. Clostermann invents Hurricane losses. The Hurricanes as of 1941 were not air superiority fighters in Western Europe, they were bomber destroyers and fighter bombers, more survivable than the light bombers available. Far from death traps.
In the period 1941 to around end 1942 the Luftwaffe fighters in the west generally had better performance aircraft, better tactics and more experienced pilots, while fighting over friendly territory, a reversion to much of WWI air fighting. In addition they had no reason to engage, there were few targets the Germans cared about in the area and in any case not enough bomb lift to hurt those targets. The Luftwaffe fighters engaged when things looked favourable. Hence stories of Bf109 putting on aerobatics displays alongside RAF formations to lure the RAF fighters to where they could be hit by the Fw190 waiting up sun. In mid 1942 the Germans had to account for the fact some Spitfires were much better than others but no way to tell them apart in the air, then towards the end of 1942 a viable bomber force began to appear. That forced engagements.
In 1942 the Spitfire V was in trouble as it was the main target, in 1943 it did better as the bombers were the main target.
by 1944, even the best performing Merlin Spitfires were being relegated to unsuitable fighter-bomber roles in the 2nd TAF.
The Typhoon was "relegated" from air superiority to fighter bomber just about from the start thanks to the Sabre's poor altitude performance. The Spitfire "relegation" idea would be a surprise to the RAF as June and July 1944 come in 4 and 5 in terms of kill claims for WWII after the 3 months in 1940. And that is with the Tempest, Spitfire XIV and Mustang units mostly stopping V-1 over Britain, leaving the mark IX to do most of the air superiority work over Normandy. Overlord was the European Theatre 1944 make or break operation, even the heavy bomber forces found that out. Leigh-Mallory was right about Overlord provoking big air battles, but no one was willing to assume the Luftwaffe would be mainly ineffective. Converting Merlin Spitfires to fighter bombers was inevitable and the usual progression as better performance types like the mark XIV and Mustang came along.
Britain began receiving Merlin Mustangs in September 1943, with 276 imported by the end of 1943 and another 174 January to May 1944 inclusive.
Realistically, only the Mustang & Mosquito were making good use of the Merlin (plus the Lancaster, technically if not tactically).
Realistically think of the near immunity from air attack allied airfields in Britain enjoyed, the inability of Luftwaffe reconnaissance aircraft to monitor Overlord preparations, and the bombing created isolation of the Normandy area. On another front note the Sabre VII was a post war engine, also skimming the production reports it looks like the RAF never bought one.
Edit; According to D.N. James, in his book 'Hawker An Aircraft Album' on page 73, late production Hurricanes did indeed have a
"...universal wing" & yes, they were sent to Burma.
The question was about internal armament, changing Hurricane II armament between A, B, C and D required a wing change, unlike the Spitfire "C" wing idea, though of course the Hurricane B wing could and did have the outboard machine guns deleted. The detailed mark IIC weights quoted by Francis Mason use 364 cannon rounds.
Hurricane mark IV, Merlin XX, special low attack wing. These wings contained basic armament of 2 x 0.303 inch Browning machine guns and catered for the following alternative installations, which were carried under the wings, two "S" type guns (40mm) or two B.H. type guns, (40mm) or eight Rockets (25 or 60 pound warheads) or two 250 or 500 pound bombs or two SBC (small bomb containers) or SCI (smoke curtain installation) or two 45 or 90 gallon drop tanks, without needing to make changes in the wings or cockpit. Mark IV built December 1942 to March 1944, IIC production continued until July, 1 mark IV built in March, 395 IIC March onwards. So what is late production? If you read messages you would see I note the mark IV arrival in India.
The Hurricane IV, and additional Hurricane production in general, was needed thanks to the Sabre situation, the proposed Hurricane V if the Sabre situation continued.
Well, yeah, but for some extra chance of survival in A2G post D-day, the Typhoon received a kit, 'Mod 347: additional armour, removable parts' (496lb!), something Hurricane pilots would've loved to have had, but hated to tote, with just a 'pissy' Merlin.
That sort of protection was in the up armoured Hurricane V, using the higher powered Merlin 27, providing around 1,640 HP for take off, the 141 engines built starting in November 1943 were converted to Merlin 25 for Mosquitoes. The extra armour would push the Hurricane loaded weight to about the empty weight of the Typhoon, possibly giving the loaded Hurricane V a slightly better power to weight ratio.
