What is the turn radius for 180-degree turn on the E170?

• A. 54' 8"
• B. 59' 2"
• C. 50' 0"
• D. 60' 0"

Answer: (A)

Turning radius on the ground is about how much space the aircraft needs to complete a turn, which depends on the geometry of the landing gear and how far the nose gear can steer. When you execute a 180-degree turn, you’re tracing a semicircle, so the space required is the radius of that circle. For the Embraer 170, the published 180-degree turn radius used for taxi planning is 54 feet 8 inches. This figure comes from the maximum nose-wheel steering angle and the aircraft’s wheelbase, giving a predictable clearance path to avoid contact with the wings, fuselage, or surrounding equipment. The other options aren’t the manufacturer’s standard turn radius, so they would imply more or less space than is typically available or safe in a ramp environment. In practice, crews use this spec to judge whether a turn can be made in a given area, and adjustments may be needed if there are obstructions or weight-on-wheels conditions alter the precise path. If you want to see how it’s calculated in detail, the Ground Handling Manual or aircraft performance data for the E170 will have the exact figures and method.