BBC Microbit; Motor control

Hi! I’m designing a model RC plane for the BBC microbit as part of my DT alevel project; I have designed a circuit using an L293D H-bridge IC, controlling two motors as well as two servos. The Circuit works however for the plane to gain enough momentum to fly a larger velocity is needed and the motors I am using fail to meet this requirement. I have tried Brushless motors (from a quadcopter build which when used with their flight controller are able to reach a high RPM (capable of flight) as well as brushed motors. When testing the brushless motors with the Microbit the only way I could increase their speed was by adding more batteries to power it
This adjusted the speed gradually but not to a flight worthy amount. As a result I am unsure whether to just by a RC plane motor and attempt to use the battery for that to power my circuit;
or if there is a way to adjust the max velocity setting/power outage on the microbit then I’m all ears. Thanks for reading!