The time between the World Wars saw some amazing developments in fighter technology, only surpassed by what came with the beginning of the jet age (which is worth another article altogether).
One of the most significant developments was the move from bi- to monoplanes. The move was not a quick or fast one and different nations did it at different times. Towards the middle and late 1930’s, there were a number of advanced biplane designs in the arsenal of various major air forces around the world.
One of them, the Grumman F3F is the direct ancestor of the famous US Navy fighters Wildcat and Hellcat.
I also think some of these advanced designs are some of the most beautiful biplanes ever to take to air.
Here is a small selection:
The Gloster Gladiator
The Gloster Gladiator is one of the most famous, if not the most famous, of the late biplane designs. Developed in the early 1930’s, it saw action on all fronts and with a number of air forces during the Second World War. Although facing more advanced monoplanes most of the time, it held its own reasonably well.
Interestingly, the last Gladiator in active service was retired in 1953, well into the jet age.
Now on to the aforementioned:
One of the most attractive biplane designs ever, in my opinion, the Grumman F3F entered active service in 1936 and was withdrawn in 1941 just before the USA entered the Second World War. Thus, there are no combat records, but, as I said, it is the predecessor of the F4F Wildcat, one of the most famous fighters of the War.
Fiat CR 32
As you can probably guess, the Fiat CR 32 was an Italian design. First deployed in 1933 it saw extensive action in the Spanish Civil War, fighting for the Nationalists, and performed so well, the high command of the Italia air force was convinced, the CR 32 would still be suitable for combat in the action against Commonwealth forces in North Africa. This was obviously incorrect. Still, the CR 32 could still claim some success against its more advanced monoplane opponents, and it, too, remained in service for a long time. Franco’s Spain retired the last one in 1957.
The Soviet Polikarpov I-15 first took to the air in 1933 and like the Fiat CR.32 saw action in the Spanish Civil War. It was one of the main fighters of the Republicans. It was also delivered to the Kuomintang government of China and saw action against Japanese forces. When Nazi Germany invaded the USSR, they were still fielded in substantial numbers, mostly in a ground attack role, but were soon withdrawn from frontline service.
The plane survives in substantial numbers and can be seen in action at air shows:
But no list would be complete without listing a German model as well:
Heinkel He 51
The Heinkel He 51 came in several variants, among them a seaplane. When the He 51 first entered service in 1935, it was outdated even compared to state-of-the-art biplanes. Still, it was delivered to the Spanish Nationalists and performed well against its initial opponents, older biplanes like the Nieuport-Delage NiD 52, but soon met more than its match in adversaries like the Polikarpov above.
The He 51 remained in a ground-attack role during the entirety of the Spanish Civil War, though. It did not see action in World War Two.