According to the standard lapse rate, how many Fahrenheit degrees are gained or lost per 1,000 feet?

According to the standard lapse rate, how many Fahrenheit degrees are gained or lost per 1,000 feet?

• A. 3.0
• B. 3.3
• C. 3.5
• D. 4.0

Answer: (C)

The temperature in the standard atmosphere falls with altitude. The typical lapse rate is about 2°C per 1,000 feet. When you convert that to Fahrenheit, 2°C is roughly 3.6°F, and aviation practice uses 3.5°F per 1,000 feet as the standard value. So, for every 1,000 feet you climb, the air cools by about 3.5°F (and it warms by about 3.5°F per 1,000 feet if you descend). This is why the correct amount gained or lost per 1,000 feet is approximately 3.5°F.

The temperature in the standard atmosphere falls with altitude. The typical lapse rate is about 2°C per 1,000 feet. When you convert that to Fahrenheit, 2°C is roughly 3.6°F, and aviation practice uses 3.5°F per 1,000 feet as the standard value. So, for every 1,000 feet you climb, the air cools by about 3.5°F (and it warms by about 3.5°F per 1,000 feet if you descend). This is why the correct amount gained or lost per 1,000 feet is approximately 3.5°F.