sentences:  This made it very vulnerable to enemy fighters later in the war, once they became fast enough to actually catch it.The flight characteristics of the Ki-48 also left much to be desired.Newer generations of Allied fighters caught up in speed, and eventually, the Ki-48 was too slow to outrun them, while superior modern Japanese aircraft, such as the Yokosuka P1Y and the Mitsubishi Ki-67, could only be produced in small numbers.