Question

For a jet airplane, the maximum rate of climb occurs at the speed where

• A. Thrust required is minimum
• B. Drag is minimum
• C. Excess thrust is maximum
• D. Excess power is maximum

Hint:

For aircraft performance, \[ \boxed{ \text{Maximum Rate of Climb} \Longrightarrow \text{Maximum Excess Power} } \] whereas \[ \boxed{ \text{Maximum Angle of Climb} \Longrightarrow \text{Maximum Excess Thrust}. } \]

Answer 1

The Correct Option is D

Step 1: Recall the relation for rate of climb. The rate of climb (ROC) of an aircraft is given by \[ \boxed{ \text{Rate of Climb} = \frac{\text{Excess Power}}{\text{Weight}} } \] where \[ \text{Excess Power} = \text{Power Available} - \text{Power Required}. \]

Step 2: Determine the condition for maximum rate of climb. Since the aircraft weight remains constant, \[ \boxed{ \text{Maximum ROC occurs when Excess Power is maximum.} } \] Therefore, \[ \boxed{\text{Excess power is maximum}} \] is the correct answer. Thus, \[ \boxed{(D)} \] is the correct answer.