Descending from 3,000' MSL to 1,000' MSL at 500 FPM. You're flying 120 knots groundspeed. How far will you travel by the time you reach 1,000' MSL?

Descending from 3,000' MSL to 1,000' MSL at 500 FPM. You're flying 120 knots groundspeed. How far will you travel by the time you reach 1,000' MSL?

• A. 4 miles
• B. 8 miles
• C. 6 miles
• D. 10 miles

Answer: (B)

To figure out how far you’ll travel during the descent, connect time and distance using the given rates. You’re shedding 2,000 feet (from 3,000' to 1,000' MSL). At a descent rate of 500 feet per minute, that takes 4 minutes. With a groundspeed of 120 knots, you cover 120 nautical miles in 60 minutes, which works out to 2 nautical miles per minute. In 4 minutes you’ll travel 2 nm/min × 4 min = 8 nautical miles. So the distance you’ve flown by the time you reach 1,000' MSL is 8 nautical miles (about 9.2 statute miles, but aviation distances are typically given in nautical miles).

To figure out how far you’ll travel during the descent, connect time and distance using the given rates. You’re shedding 2,000 feet (from 3,000' to 1,000' MSL). At a descent rate of 500 feet per minute, that takes 4 minutes.

With a groundspeed of 120 knots, you cover 120 nautical miles in 60 minutes, which works out to 2 nautical miles per minute. In 4 minutes you’ll travel 2 nm/min × 4 min = 8 nautical miles.

So the distance you’ve flown by the time you reach 1,000' MSL is 8 nautical miles (about 9.2 statute miles, but aviation distances are typically given in nautical miles).