Final answer:
As the airplane takes off and accelerates while gaining height, both its kinetic energy and gravitational potential energy increase.
Step-by-step explanation:
Just after taking off, the aeroplane continues to accelerate as it gains height. During this time, one form of energy that increases is the kinetic energy of the airplane. As the plane speeds up, the kinetic energy (the energy it possesses due to its motion) increases. Additionally, since the airplane is gaining height, its gravitational potential energy also increases. This is because gravitational potential energy is directly related to the altitude of an object above a reference point, typically the ground.