This is the Realism Series: Nakajima Kikka, perhaps the most realistic realism series craft I've done yet.

The aircraft is near identical to the real one in terms of engine thrust, RATO thrust (use 1 to detatch RATOs), wing area, armament, dimensions, empty weight and loaded weight. However, you'll notice one thing. It barely flies. Barely. Even though the real Kikka had a notably long takeoff run, at least it could accelerate to some speed after takeoff, with a top speed of 423mph.

This thing? Well, it just doesn't. It hangs at around 160-180mph, and just stays there. Never accelerates further. This must be a fault of the SimplePlanes engine, as I made sure to double- and triple-check all of the aircraft's statistics with the real one from various sources. I'm fairly certain the problem is not from too much drag; SimplePlanes wings are extremely aerodynamic from a WW2 plane point of view, and every single of my other Realism Series WW2 planes are significantly faster than their real-life counterparts, apart from the Me 262 and Kikka. This is why I'm certain it must be the game at fault.

TLDR: SimplePlanes jet engines don't seem to be producing enough power; this historically accurate Kikka doesn't go anywhere near historically accurate speeds.

Side note: When using the RATO, do not begin pulling up until above around 130mph; the real Kikka crashed following a failed takeoff when the RATO units forced the tail into dragging across the ground, giving the pilot almost no elevator control. This Kikka will do this, too. Also, the landing gear will not retract until the RATOs are ejected.

Side note 2: The Kikka was armed with a single 30mm cannon, which was very difficult to aim and somewhat innaccurate. I tried to simulate that with this one, and the 30mm gun is slow-firing and innaccurate.