Each nation during the war produced aircraft that were either not fully developed to their potential or never saw service although they might have. Some of these aircraft had the potential to be better than those that actually saw service. What would be your picks (let's keep it to five per nation max at this point for sake of brevity): Note, this list should not include prototypes that clearly were never going to see service by war's end (ie the Martin Baker MB 5 for example); that helps shorten the list and eliminate some of the very late war prototypes. A few of my picks: The Bloch MB 157. 441 mph in 1940! It would have made a really top notch fighter. Of course, France fell and it disappeared into obscurity. The Henkel He 100D. Could have replaced the Me 109 and probably should have. The Vought TBU Sea Wolf. A competitor for a replacement for the SB2U Vindicator torpedo bomber. Clearly better than Grumman's TBF Avenger. Vought simply could not produce sufficent numbers so the TBF was picked. Just 180 got produced. There was the potential that the Navy could have found other manufacturers to build it.
Do 219. Bloch 157 was protoype, did it actually fly in 1940? at that speed/ or was it projected to hit that speed? http://www.simviation.com/fsdcbainbloch.htm Always thought that was a bit of a missed opportunity. Dewoteine 520 was built after occupation.
Westland Whirlwind SAAB J-22 SAAB J-21 looks cool Reggiane Re 2005 Piaggio P. 108B four engine bomber, some had 75 mm cannon Henschel Hs 129 good idea, bad engines Dewoitine D 520 Polikarpov I-17 Archangelskii Ar-2 hard to get much information on this plane but it looks good.
The Vickers Windsor - probably the right decision to drop it as the Lancaster got the job done. Interesting aircraft, though.... http://avia.russian.ee/air/england/vickers_windsor.html
Not sure the Skyraider can be included...but an excellent ground attack bomber. http://www.geocities.com/eepohsan/skyraider.html
A short commentary: The single prototype MB 157 was captured by the Germans and tested extensively in late 1942 early 43 before being discarded. The 441 was a good speed. The problem with the Italian models was usually lack of production capacity or engines. Many of their later aircraft, like the Re 2005, used scarce German powerplants. So, while these were often very good planes there was simply no way they could be produced in any quantity. The Fw 187 certainly did have potential. The biggest problem I see with it was the design was very tight. Some engine insturments had to be mounted on the nacelles themselves due to lack of room in the cockpit. This certainly would have limited its usefulness as say, a nightfighter (no room for radar equipment). But, in 1940 it had alot of potential as a long range fighter. It probably would have proven very useful in Russia in that role. The Hs 129 on the other hand was simply that it was too small. Better engines would not fix the size problem. Bigger engines on a somewhat larger aircraft would have been an optimal solution. The larger aircraft could have lugged the necessary tank busting cannon internally or in a pod where it didn't cripple the aircraft's performance. Actually, the French had a number of good designs that died as prototypes or on the drawing board with their surrender. The Dewoitine 520 had alot of problems besides being a bit underpowered. It was marginally stable making it a poor gun platform. Its stall characteristics were abysimal giving the pilot no warning and requiring alot of height loss to recover from. On the whole, the Arsenal VG 33 series or Bloch MB series showed more potential than the Dewoitine. Now, the Polikarpov situation is probably unique. Polikarpov was sacked by Stalin in 1940 over the Red Air Force's debacle with the Japanese in the various Sino-Soviet border conflicts where his designs suffered very heavy losses in combat. Now, while this had as much to do with the excretable levels of experiance and training of Soviet pilots as any deficencies in their aircraft, Stalin would hear none of it. The Polikarpov design bureau was finished. Lavochikin, Yakovlev and MiG got the nod as the replacements while Polikarpov got the sack. Such are the vagraties of working for a brutal dictator! Westland's Whirlwind suffers the same problem as the Hs 129; its airframe is just too small to take larger engines. The Peregrins were about the limit on it. So, while it remains a very fine looking fighter it simply lacked the size necessary to upgrade it sufficently to keep pace with aviation developments. Note, that Brewster made the same error with their aircraft allowing Grumman to jump ahead in the US Naval aviation field. Had the Buffalo been able to be adapted to a two bank radial engine the F4F Wildcat would likely never have reached service with the USN. But, Brewster Aircraft could not wedge such an engine into its design and lost the race. But, the Whirlwind was not the last of its line. The Westland Welkin did see limited service late in the war as a specialized high altitude fighter. The Whirlwind lineage is clear in its lines.
Polikarpov I-185, Dornier 335 : both reached operational tests, but the Polikarpov never entered mass production (see TAG's post above about Polikarpov's disgrace). Thus plane was a beast for its time, but doomed by Stalin's favor for Yakovlev, and the lack of engine (all the engines produced were needed for other planes already under mass production). I'm not sure if the Do335 belong to this category : it was not discarded, but it was delayed up until it was too late. I'll add the Sukhoi Su-2, an excellent attack/light bomber.
XP 40 Q. Can't help but wonder if it would've outperformed Mustang, ( except in range ), with 1776 HP Merlin, ( or 1695, whichever it is ), instead of 1425 hp one. http://kits.kitreview.com/images/XP-40Q-09-13-05-proof-WEB.jpg There were three XP-40Q prototypes, one converted from a P-40N and the other two converted from P-40K's. It was indeed the ultimate P-40. Maximum speed was 422 mph at altituded, and since it had a two-stage turbosupercharger it would operate at the altitudes that the Mustang and Thunderbolt were used to operating at. It was powered by an Allison V-1710-125 engine producing 1,425-hp., and of course as I said, it has the turbosupercharger. Armament was four Browning .50 caliber machine guns on the prototypes, while production models would have gone back to six guns. http://www.internetmodeler.com/2003/april/columns/XP-40Q-1.jpg
I would like to add one more: The Arado Ar 232 It had alot of advanced features and these were copied somewhat after the war in the Nord Atlas and C-119.
A couple of interesting projects that I wish had not be subjected to the whims of committes are the Amerika Bomber original concept. And the Horten Ho X fighter design.
Henschel 127 (faster than the Ju 88 , should have been something like the mosquito) Or is it just an hoax?
I agree the Windsors tail is not "pretty" but it is a high aspect ratio vertical stabilizer and ahead of it's time. Reduces drag in straight line. The B 24 and 289 had high aspect ration wings, long and thin. Modern day racing sail boats have high aspect sails and keels. Otherwise the Windsor was an efficient design and I find rather aesthetically pleasing.
Here's a Finnish "Pyörremyrsky" (Hurricane): VL Pyörremyrsky - Wikipedia, the free encyclopedia The use of wood in the construction of the aircraft was maximised due to the sparseness of metals. The goal was to create a fighter with similar flight qualities to the German Messerschmitt Bf 109G The Pyörremyrsky design was considered quite successful. It could outclimb the Bf 109G-6 and it was very manoeuvrable. The only major problem with the design was found to be the low-quality glue used in the joints.
Hmm whilst an interesting aircraft and no doubt capable...all i could see that was P-40 was the rudder...this is a completely different aircraft.