In 3 statute miles of gliding at an angle of attack of 8 degrees, what altitude is lost?

In 3 statute miles of gliding at an angle of attack of 8 degrees, what altitude is lost?

• A. 1,320 ft
• B. 660 ft
• C. 2,640 ft
• D. 3,960 ft

Answer: (A)

The key idea is glide ratio: how far you can travel forward for each unit of altitude you lose. If you know the forward distance and the aircraft’s best-glide ratio (L/D), you can find altitude lost by dividing the forward distance by that ratio. For a typical light aircraft at a moderate angle of attack around 8°, the best-glide ratio is commonly about 12:1. That means for every 12 units of forward travel, you lose 1 unit of altitude. With 3 statute miles of forward glide, the altitude lost is 3 miles divided by 12, which equals 0.25 miles. Converting 0.25 miles to feet gives 0.25 × 5,280 = 1,320 ft.

The key idea is glide ratio: how far you can travel forward for each unit of altitude you lose. If you know the forward distance and the aircraft’s best-glide ratio (L/D), you can find altitude lost by dividing the forward distance by that ratio.

For a typical light aircraft at a moderate angle of attack around 8°, the best-glide ratio is commonly about 12:1. That means for every 12 units of forward travel, you lose 1 unit of altitude. With 3 statute miles of forward glide, the altitude lost is 3 miles divided by 12, which equals 0.25 miles. Converting 0.25 miles to feet gives 0.25 × 5,280 = 1,320 ft.