What is the takeoff ground roll distance with a 50-foot obstacle?

What is the takeoff ground roll distance with a 50-foot obstacle?

• A. 1,340 feet
• B. 1,200 feet
• C. 1,500 feet
• D. 2,000 feet

Answer: (A)

Takeoff performance with an obstacle hinges on two parts: accelerate to liftoff speed on the ground, and then climb early enough to clear the obstacle. The takeoff distance with a 50-foot obstacle represents the total runway distance required to both reach liftoff and to gain enough altitude to clear that 50-foot height, using the aircraft’s weight, density altitude, wind, and configuration. In this case, the performance data show you need 1,340 feet to meet that objective. That value reflects the added distance needed to satisfy the climb gradient to clear the obstacle after liftoff. The other numbers would not align with the chart data for these conditions, which is why 1,340 feet is the correct choice.

Takeoff performance with an obstacle hinges on two parts: accelerate to liftoff speed on the ground, and then climb early enough to clear the obstacle. The takeoff distance with a 50-foot obstacle represents the total runway distance required to both reach liftoff and to gain enough altitude to clear that 50-foot height, using the aircraft’s weight, density altitude, wind, and configuration. In this case, the performance data show you need 1,340 feet to meet that objective. That value reflects the added distance needed to satisfy the climb gradient to clear the obstacle after liftoff. The other numbers would not align with the chart data for these conditions, which is why 1,340 feet is the correct choice.