On a 1-degree descent, altitude loss per nautical mile is:

On a 1-degree descent, altitude loss per nautical mile is:

• A. 50 feet
• B. 100 feet
• C. 150 feet
• D. 200 feet

Answer: (B)

The idea here is that the vertical drop you accumulate is tied directly to the descent angle and how far you travel forward. For a 1-degree descent, the slope is small, so the altitude you lose per nautical mile is a modest number. Using the exact relationship, vertical drop per one nautical mile equals tan(1°) times 1 NM. Since tan(1°) is about 0.0175 and 1 NM is about 6,076 feet, the precise drop is around 106 feet per nautical mile. In flight practice, though, a handy rule of thumb is that 1 degree of descent corresponds to about 100 feet lost per nautical mile. This quick approximation makes mental math easy during planning and flight, and it aligns with the common teaching that a shallow 1° descent yields roughly 100 ft per NM. If you do the exact math, you’d get a bit more than 100 ft, but rounding to 100 ft per NM is the standard convenient figure.

The idea here is that the vertical drop you accumulate is tied directly to the descent angle and how far you travel forward. For a 1-degree descent, the slope is small, so the altitude you lose per nautical mile is a modest number. Using the exact relationship, vertical drop per one nautical mile equals tan(1°) times 1 NM. Since tan(1°) is about 0.0175 and 1 NM is about 6,076 feet, the precise drop is around 106 feet per nautical mile. In flight practice, though, a handy rule of thumb is that 1 degree of descent corresponds to about 100 feet lost per nautical mile. This quick approximation makes mental math easy during planning and flight, and it aligns with the common teaching that a shallow 1° descent yields roughly 100 ft per NM. If you do the exact math, you’d get a bit more than 100 ft, but rounding to 100 ft per NM is the standard convenient figure.