What was the largest single-seat fighter of conventional configuration developed during World War II?

By largest-I mean heaviest-loaded weight. It also tested something new-bonus for that.

6 days later

Hello Doug- Are you referring to the P-47 Thunderbolt? (loaded weight- 12,731 lbs)

No, I am not. That was an expected submission, however. And the Thunderbolt did not test/introduce something new in comparison, to my knowledge. Think heavier single-seat fighter developed in that era. Clue: it was heavier empty than a P-47D model Thunderbolt which my info gives as a gross weight of 14,000 lbs.

Hmmm.... developed... but not deployed?

Perhaps you are thinking of the Douglas A-1 Skyraider? (18,000 lb loaded)

Technically speaking, the 18,263 lb (loaded) Douglas AD-1 was not a Fighter aircraft-it was a a Naval carrier-borne Attack aircraft. I'm looking for that heavy Fighter aircraft developed during WWII. Please keep trying.

Maybe... the aircraft didn't go into production?

Could it be the Boeing XF8B? (20,000 lb loaded)

I think SunvisorFlyer may well be correct with the Boeing XF8B-1. It was fitted with 2 three bladed contra rotating props. Was this the new innovation?

Well, SunVisor Flyer-you have caught me in a bit of a conundrum here, as I just didn't think of the Boeing XF8B as a true Fighter aircraft, despite it's nomenclature. It also was a torpedo bomber, a dive bomber as well as an escort fighter by designation/s. And yes, it was heavier than my Quiz question fighter, which flew at a time when nomenclatures were changing from P- for Pursuit to F- for Fighter. The XF8B weighed a hefty 20,508 lbs loaded, with a max takeoff weight of 21,691 lbs. Its engine power was one P&W XR-4360-10 of 3,000 Hp.

I do not know, however, that it EVER played a role developing or testing something new (even though it USED that something new I was referring to). I will get back to that in my next paragraph-so stand by.

I had in mind for this quiz the Curtiss-Wright Corp. XP-62 that they intended to replace the many variations of the iconic but aging Curtiss P-40 Tomahawk; which single engine single seat fighter variations included the Curtiss Warhawk and Kittyhawk variations all derived from the Curtiss P-36 Hawk which first flew in 1935, a couple years after my birth. And, the sole Curtiss XP-62 in mind was also the first used (by several months) to test counter-rotating propellers-two three-blade propellers were on the sole XP62 driven by a Wright R-3350-17 radial engine of 2,300 Hp. The XP62 was designed for several missions as noted above, but never entered production. Only one XP62 was built and flown.

The Curtiss XP-62 had a loaded weight of 14,660 lbs AND a max takeoff weight of 16,651 lbs. Production was initially planned for 100 P-62 fighters from a contract award of May 25, 1942. However, this contract was cancelled BEFORE P-62 construction could begin when Curtiss-Wright was awarded a wartime contract to build (Republic) P-47 Thunderbolts which were of higher, immediate priority. WWII American pilots referred to the P-47 Thunderbolt fighter affectionately as the "Jug", and it was a major force in the war in Europe. The "Jug" could take a lot of punishment and still return to base, destroying 3,752 enemy aircraft in air combat. A total of 15,660 P-47s were produced.

How about considering this quiz to be over-with your noted good input to stand, unless others wish to offer any insights.