For an aircraft with standard winglets, the minimum turn radius obstruction clearance path is determined by which part of the airplane?

• A. Horizontal stabilizer tip
• B. Wingtip
• C. Fuselage center
• D. Nose gear

Answer: (A)

When thinking about obstacle clearance in a turn, the crucial idea is that the limit is set by the part of the airplane that traces the largest circle around the turn center. With standard winglets, the horizontal stabilizer tip ends up being the part that reaches farthest aft in the turning plane, so it defines the outer boundary of the aircraft’s turning envelope. As the aircraft banks and the tail swings through the turn, the stabilizer tip follows the largest radius path, establishing the minimum turn radius needed to stay clear of obstructions. The other parts—fuselage center or nose gear—stay closer to the turn center, and while winglets increase wingspan, they don’t typically govern this outermost path in the same way the tail tip does.