When a jumbo jet slows and descends on the approach to landing, there is a decrease in both its kinetic and potential energy. where does this energy go?

Answer;

The energy turns into heat, or thermal energy.

Explanation; According to the law of conservation of energy; energy can not be created or destroyed, but can be transformed from one form to another. Therefore; a decrease in kinetic energy and potential energy when a jumbo jet slows and descends on the approach to landing, indicates a transformation energy to another form, which is heat energy or thermal energy but not destruction of energy.