Curious about two things. 1.) what 'lighter but stronger" alloys were used? The airframe industry was pretty well settled into using aluminum and steel - both of which remained same weights respectively although the strengths (and brittleness) increased as 20224-T4 improved over Alclad 17ST but AFAIK there were no material/alloy changes made to the Fw 190 wing thoughout the war.
2.) what 'redesign' of either main spar or torque box was made to increase stiffness of the Fw 190 wing.
Essentially you have to either increase the depth of a spar, increase the beam cap area of the beam or increase the surface skin thickness on top and bottom side of the wing in the spar area to increase bending stiffness.
Thats not true, you don't have to add metal to increase the stiffness... The simplest example....
Take a metal rod that is solid, try and bend it, then take a metal rod that is hollow on the inside (a tube), try and bend it, you will find that the tube/hollow one is harder to bend, so in that regard, it is 'stiffer'. Now what changes they might have made to the 190, I have no idea, but the idea that more metal is required to increase stiffness/strength in regards to a particular force is bogus.
Keep in mind it was not just the wing that was redesigned in the A6, they also streamlined the bomb/external fuel tank fitting to be stronger and more streamlined. Also, they changed the shape of the storage port and improved the radio system too. The A6 was not an A5 with more guns, it had substantial changes.
A general list of changes..
Fw 190 V1 Prototype Model; fitted with BMW 139 engine of 1,550 horsepower.
Fw 190 A – Base production model
Fw 190 A-0 Preproduction Model Designation; 28 examples produced.
Fw 190 A-1 – Role specific optimized variant; appeared in June 1941; fitted with BMW 801C-1 engines of 1,560 horsepower; longer propeller; 4 x 7.92mm machine guns (2 in fuselage and 2 in wing roots) and 2 x 20mm cannons in outboard wings; bulged engine cowlings.
Fw 190 A-2 – Role specific optimized variant; appeared in October 1941; fitted with BMW 801 C-2 engine of 1,600 horsepower; redesigned exhaust system; upgraded gun sight; 2 x 7.92mm machine guns in fuselage and 4 x 20mm cannons (2 replaced original 7.92mm machine guns) in wings.
Fw 190 A-3 – Role specific optimized variant; appearing in spring of 1942; fitted with BMW 801 D-2 engines of 1,754 horsepower; centerline bomb rack.
Fw 190 A-3a First appearing in fall of 1942; Turkish export versions; fitted with 4 x 7.92mm machine guns and 2 x 20mm cannons (same as A-1 model).
Fw 190 A-4 – Role specific optimized variant; appeared in July 1942; improved radio equipment; similar to A-3 in most respects (armament/engine).
Fw 190 A-4/U1 Centerline bomb rack fitted; MG 151 cannons retained but all other machine gun armament removed.
Fw 190 A-4/U3 Similar to U1 model; some converted to nightfighter duty; served as basis for Fw 190 F-1 ?assault? fighter version.
Fw 190 A-4/U4 Dedicated Reconnaissance Platform; fitted with photographic cameras; armament of machine gun and cannons fuselage mounted.
Fw 190 A-4/U7 High-Altitude Variant; compressor intakes implemented on side cowlings.
Fw 190 A-4/U8 Would later serve as basis for Fw 190 G-1 model.
Fw 190 A-4/R6 Fitted with underwing rocket mortar weaponry
Fw 190 A-5 – Role specific optimized variant; revised engine placement; fitted with BMW 801 D-2 engine of 1,700 horsepower; MW 50 power boost capable.
Fw 190 A-5/U2 Dedicated Nightfighter; 2 x 20mm MG151 cannons.
Fw 190 A-5/U3 Nightfighter with provision for fuel tanks and bombs; 2 x 20mm MG151 cannons.
Fw 190 A-5/U4 Dedicated Reconnaissance Fighter; fitted with cameras.
Fw 190 A-5/U8 Nightfighter fitted with underwing racks for centerline bombs and underwing fuel drop tanks; 2 x 20mm MG151 cannons; later to become the Fw 190 G-2 model series.
Fw 190 A-5/U12 Bomber Interceptor Variant; fitted with two underwing gun pods for array of 2 x 7.92mm machine guns and 6 x 20mm MG151 cannons.
Fw 190 A-5/U12 Prototype Model
Fw 190 A-5R11 Nightfighter Conversion Model; fitted with radar.
Fw 190 A-6 – Role specific optimized variant; new wing design; extra ammunition for 2 x 7.92mm fuselage machine guns and 4 x 20mm wing-mounted cannons; improved radio navigation system; streamlined centerline bomb/fuel rack fitting.
Fw 190 A-7 – Role specific optimized variant; based on the Fw 190 A-5/U9 prototype; fitted with BMW 801 D-2 engine of 1,700 horsepower; 2 x 20mm MG 131 cannons replacing standard MG17 7.92mm fuselage machine guns; upgraded gun sight.
Fw 190 A-8 – Role specific optimized variant; improved bubble canopy.
Fw 190 A-9 Final A-Series Production Models; fitted with BMW 801S engines of 1,973 horsepower; improved engine armor protection; improved radiator system.
Fw 190 A-10 High-Altitude Prototype Development
Fw 190 B – Wider wing span; higher altitude capability; pressurized cockpit; turbocharged BMW 801 engine.
Fw 190 C – High altitude capability; turbocharged Daimler-Benz DB 603 powerplant.
Fw 190 D Dora – Main service model by 1944; fitted with Junkers Jumo 213 supercharged engine.
Fw 190 D-0 Developmental Prototype; fitted with Jumo 213a engine.
Fw 190 D-1 Developmental Prototype
Fw 190 D-2 Developmental Prototype
Fw 190 D-9 – Role specific optimized variant
Fw 190 D-10 – Role specific optimized variant
Fw 190 D-11 – Role specific optimized variant; fitted with uprated Jumo 213E engines; 17 examples produced.
Fw 190 D-12 – Role specific optimized variant; based on D-11 model; Mk 108 30mm cannon in propeller hub.
Fw 190 D-13 – Role specific optimized variant; based on D-11 model; Mk 151/20 20mm cannon in propeller hub.
Fw 190 D-13/R11 All-Weather Development
Fw 190 E - Proposed reconnaissance fighter
Fw 190 F – Ground attack model based on Fw 190 A-4 powerplant.
Fw 190 F-1 Improved under-fuselage armor; centerline and wing bomb racks.
Fw 190 F-2 Based on Fw 190 A-5/U3; replaced F-1 series on production lines.
Fw 190 F-3 Based on Fw 190 A-5/U17; 432 examples produced.
Fw 190 F-4 Abandoned Strafing Design Variant
Fw 190 F-5 Abandoned Strafing Design Variant
Fw 190 F-6 Abandoned Strafing Design Variant
Fw 190 F-7 Abandoned Strafing Design Variant
Fw 190 F-8 Improved radio equipment; redesigned compressor for low-altitude boost in performance; 2 x 20mm MG151/20 cannons in wing roots and 2 x 7.92mm MG131 machine guns above engine housing; 3,400 examples produced.
Fw 190 F-8/U1 Long-Range Nightfighter; underwing and centerline provision for fuel tanks and/or bombs.
Fw 190 F-8/U2 Torpedo Bomber
Fw 190 F-8/U3 Heavy Torpedo Bomber
Fw 190 F-8/U4 Nightfighter
Fw 190 F-9 Based on the Fw 190 A-9; redesigned empennage as found on the Ta 152 development; 147 examples produced.
Fw 190 G Long-Range Attack Model; based on the Fw 190 A-5 powerplant.
Fw 190 G-1 Based on the Fw 190 A-4/U8
Fw 190 G-2 Based on the Fw 190 A-5/U8
Fw 190 G-3 Based on the Fw 190 A-6
Fw 190 G-8 Based on the Fw 190 A-8
Fw 190 A8-U1 Original Designation for Trainer Fw 190?s.
Fw 190 S-5 Trainer Variant
Fw 190 S-8 Trainer Variant
Ra-2 High Altitude Development
Ra-3 High Altitude Development
Ta 152 – Ultra-high altitude fighter; Wider wing span; Jumo 213E powerplant; based on the Ra-3 development model.
Ta 152C Low-Altitude Developmental Ta 152 Model; fitted with DB 603 engine; only two examples produced.
Ta 152H – Improved Ta 152; Only operational variant of the Ta 152.