The Japanese Army “Oscar” is far less known than the Navy’s Zero. Yet it has many similarities, and also served from the start to the end of the Pacific War.

So let’s take a look at an important, but less well known type.

Like many nations, Japan had two completely separate air arms.  The Japanese Army and Navy were perhaps as independent as two military branches serving one government have been in the modern world.  Yet its interesting that the philosophy and doctrine that shaped those two air arms was pretty similar.  Japanese fighters were all about maneuverability, and scoring the first hit.  So no surprise, the Oscar and Zero look a lot alike and were often confused for each other during the war.

Visible under the wing are two drop tanks for extra fuel. Among the ways the Oscar achieved lightness beyond even the Zero was with much less fuel storage (and therefore, range).

Arguably, the Ki-43 took those features of the Zero a step too far.  The Oscar was even more maneuverable; yet also lighter, slower and under-armed with no armor or self-sealing fuel tanks.  Much of that extra maneuverability came from a so-called combat flap, or “butterfly flap”.  It was a type of fowler flap on the bottom of each wing that would increase lift and rate of turn when used in combat.  Japanese tactics were all about drawing opponents in to a tight, turning fight, at which Japanese aircraft were unsurpassed.  In the early months of the war, allied pilots were often taken off guard by how great the Japanese advantage was in this sort of combat.

Visible in the upper cowling are two 7.7 mm machine guns. This was an early Oscar’s total firepower. That’s very light for a 1941 design.

In time, the Japanese advantage would ebb.  Especially as allied pilots learned they had the advantage of speed and power.  That meant the allied pilot could usually decide to not engage or break off at will.  Later Japanese fighters would address this imbalance, and the Oscar would eventually receive a bigger engine and heavier fire power.  But even so, the Oscar would always be a lightweight weapon of maneuver.  A rapier among broad swords.  It could be dangerous if taken lightly.

The Butterfly flaps are visible at the trailing edge of the wing.

This is an early Ki-43-I based in Burma during 1942.  Its from the Hasegawa kit, and has Aeromaster decals.

Zero and Oscar