The Typhoon had a design flaw like the early Bf109F causing structural failure near the tail, in both cases the fix was simple once the problem had been understood. The main Typhoon problem was the engine performance and availability.
Typhoon cumulative production was 227 by end June, 448 by end September, 714 by end December 1942 and 890 by end February 1943. The RAF Census end February 1943 says Typhoon deliveries were 832 of which 79 had been lost and 19 converted to instructional types, 271 were in squadrons 232 were in storage, the rest under repair, modification or doing experimental work. Census Typhoon situation, thanks to the engine situation a large number of older airframes were turned into spares.
Feb 43 Effective 734, lost 98 including Cat E 79
Mar 43 Effective 834, lost 117 including Cat E 101
Apr 43 Effective 922, lost 149 including Cat E 133
May 43 Effective 935, lost 212 including Cat E 152
Jun 43 Effective 897, lost 338 including Cat E 277
Jul 43 Effective 944, lost 413 including Cat E 354
Aug 43 Effective 919, lost 514 including Cat E 452
Sep 43 Effective 913, lost 603 including Cat E 539
Oct 43 Effective 971, lost 657 including Cat E 589
Nov 43 Effective 984, lost 748 including Cat E 632
Dec 43 Effective 1,060, lost 775 including Cat E 661
So either the RAF was losing an average of 100 Typhoons a month June to September 1943 inclusive or there was quite a culling, all up 387 written off in the 4 months. The Fighter Command Losses books have 72 losses for the period
Cumulative production totals Sabre II and Typhoon, then Sabre II engines under repair and Typhoon airframes in storage as of end of month
Month / Sabre II / Typhoon / Sabre under or awaiting repair / Typhoon airframes in storage
Jan-43 / 1007 / 805 / 317 / 166
Feb-43 / 1115 / 890 / 352 / 158
Mar-43 / 1222 / 994 / 417 / 158
Apr-43 / Unknown / 1097 / 482 / Unknown
May-43 / 1334 / 1200 / 595 / 244
Jun-43 / 1391 / 1264 / 643 / 183
Jul-43 / 1482 / 1357 / 735 / 153
Aug-43 / 1586 / 1437 / 861 / 149
Sep-43 / 1695 / 1547 / 887 / 304
Oct-43 / 1805 / 1645 / 901 / 176
Nov-43 / 1913 / 1753 / 897 / 206
Dec-43 / 2030 / 1851 / 871 / 265
Writing off, scrapping, reducing to spares several hundred Typhoon airframes would be needed to ensure all existing airframes had an engine plus allow for engine repairs, overhaul and reserves and the newly arriving Tempests. I do not think there was enough wrong with the early Typhoon airframes alone to require scrapping, it was engine supply.
Put it another way, as of the end of 1943, there were 1,159 (2,030 - 871) Sabre II engines available for or had been lost with Typhoons, there were 265 Typhoon airframes in storage, so assuming a maximum of 1,424 (1,159+265) Typhoons with engines or as airframes requires the scrapping or reassigning to maintenance airframe status of around 427 airframes to balance the books and this ignores there would be stand alone Sabre II engine reserves.
Leigh-Mallory wrote a letter on the Typhoon situation as of 17 December 1943.
41 with ADGB and TAF, 9 with sliding hood
56 with 41 Group including 31 with sliding hood
36 under repair
34 experimental
701 broken down
289 in purgatory storage, no engines available until September 1944
228 lost on operations.
428 require sliding hood modification apart from the 289 held in purgatory. Rocket modification is slow due to squadrons being reluctant to lose aircraft and bad weather.
End December 1943 there were 114 Typhoon Instructional aircraft, versus 120 Spitfires and 174 Hurricanes, so the lack of engines saw Typhoons preferentially made instructional, but that was not enough and converting several hundred early airframes to spares during 1943 was the best way to salvage something from the program and bring engine and airframe numbers into alignment, I doubt the 701 figure quoted by Leigh-Mallory though, it would imply a Sabre engine reserve of around 400 (114 instructional airframes, 300 airframes reduced to spares to balance numbers, another 400 reduced to spares to create the engine reserve)
The first sliding hoods were actually rebuilds from older Typhoons which had been in store at Glosters, followed by introduction on the production line (intermittent to start with) and finally a mass modification program on Typhoons in service (around 400). Tempest tailplanes were introduced with MN307 in late February 1944 but only a small number could be initially fitted with 4-blade propellers which were not normal until around MN600 in mid April 1944. As far as I am aware the fitting of the Tempest tail was tied in with the 4 blade propeller. It looks like the first 1,000 pound bombs were dropped on 23 April 1944. (AIR 16/1036)
Apart from the 2 prototypes Hawker built R8198-8200 and R8220-31, all other Typhoons built by Gloster. Hawker 5 Ia, 10 Ib, Gloster, 100 Ia 3,200 Ib.
Gloster built 1 Typhoon in June 1941, another 20 August to October 1941, then series production from December.
Contract B12148/39 Hawker, sub contracted to Gloster requisition 82/E1/39 for 105 Typhoon Ia (5 Hawker, 100 Gloster), 410 Typhoon Ib (10 Hawker, 400 Gloster). R serials. Most taken on charge by end September 1942 but some as late as April 1943. The Gloster R8xxx serials began being taken on charge mid July 1942.
Contract ACFT943 Gloster requisition TA1/E1/40 for 700 Typhoon Ib (DN, EJ serials), requisition TA3/E1/41 for 1400 Typhoon Ib (JP, JR, MM, MN, MP serials) further requisitions against this order for remaining Typhoons built (145 PD, 255 RB, 300 SW serials), by the looks of things the PD serials were 2/E11/41, the RB serials 3/E11/43.
DN serials taken on charge from late October 1942, JP serials from mid June 1943, MM serials from third week of December 1943, PD serials from late July 1944, RB serials ceased being taken on charge in early January 1945. According to the RAF Contract cards the first PD serials delivered in late July 1944, the final MP serials in the second half of August. Somewhat different to Francis K Mason's report.