If an instrument departure procedure requires a minimum climb rate of 210 feet per NM, what is the required rate of climb for a ground speed of 140 knots?

To determine the required rate of climb in feet per minute when given a minimum climb rate of 210 feet per nautical mile and a ground speed of 140 knots, it is essential to convert the climb rate into a time-based value.

First, understand that at a ground speed of 140 knots, you are traveling 140 nautical miles in one hour. Since the minimum climb rate is 210 feet per nautical mile, the total climb needed over the distance traveled can be calculated as follows:

1. At 140 knots, the aircraft covers 140 nautical miles in one hour. In terms of minutes, this speed translates to 140 nautical miles in 60 minutes.

2. To find out how many nautical miles the aircraft covers in one minute, divide the speed: 140 NM / 60 minutes = approximately 2.33 NM per minute.

3. Next, with a required climb rate of 210 feet per NM, you can calculate how many feet need to be gained per minute:

• Multiply the climb rate (210 feet/NM) by the distance covered in one minute (approximately 2.33 NM/min):

• 210 feet/NM * 2.33 NM/min = about 489.3