What is your descent gradient if you are at FL 300 and 60 DME, crossing at 10 DME at 5000 ft, with a ground speed of 300 NM/HR?

To find the descent gradient, you first need to determine the altitude loss over the horizontal distance covered during the descent.

You start at 30,000 feet (FL 300) and need to descend to 5,000 feet. This gives you a total altitude loss of:

• 30,000 ft - 5,000 ft = 25,000 ft

Next, you are informed that you are crossing at 10 DME, and your current position is at 60 DME. Therefore, the horizontal distance covered during the descent will be the distance from your current position (60 DME) to your crossing point (10 DME). This results in:

• 60 DME - 10 DME = 50 DME

To convert this distance to nautical miles, we consider that DME is in nautical miles, so horizontal distance covered is 50 NM.

Now, to find the descent gradient in feet per nautical mile (FP/NM), we use the formula:

Descent Gradient = (Altitude loss in feet) / (Distance in nautical miles)

Substituting the values you calculated:

Descent Gradient = 25,000 ft / 50 NM = 500 FP/NM

This calculation confirms