Kinetic energy increase in a plane?

QUESTION:

You watch your friend take off in a jet plane, and comment on the kinetic energy she has acquired.
But she says she has no such increase in kinetic energy. Who is correct?

Answer:

There is no doubt that she has increased her kinetic energy. As you know energy is always conserved and the fuel burned by the plane as it takes off is converted to heat, sound, light, gravitational potential energy and the kinetic energy of the plane and its passengers.

I suppose your friend is saying that she has not gained any kinetic energy relative to the plane as she is not moving relative to it. However because she was on the plane the amount of fuel used on take off would be slightly more and this additional fuel is what has given her the extra kinetic energy. Also to keep the plane moving with her on board would mean an increase in fuel during the flight because of the additional mass of the plane and your friend!