High Wind Engine Start/Rotor engagement wind limits are described by which of the following options?

• A. 60 knots within 45 degrees of the aircraft heading, or 40 knots from all other directions
• B. 55 knots within 20 degrees of the aircraft heading, or 35 knots from all other directions
• C. 70 knots within 30 degrees of the aircraft heading, or 50 knots from all other directions
• D. 65 knots within 40 degrees of the aircraft heading, or 45 knots from all other directions

Answer: (A)

When starting the engine and engaging the rotor in high wind, the important thing is how the wind hits the helicopter and how that affects rotor inflow and control during a critical phase. The limits are set to keep the rotor stable and prevent gusts from overwhelming the flight controls as you bring the rotor up to speed.

If the wind is coming from within about 45 degrees of the aircraft’s nose, you may have up to 60 knots of wind. From all other directions (more crosswind or tailward), the limit drops to 40 knots. This means a head-on or largely forward wind is more tolerable during start and rotor engagement than a strong crosswind or off-axis wind, which can cause unpredictable gust loads and harder control during rotor engagement.

For example, a wind from ahead at 55 knots is within the 45-degree window and would be acceptable, whereas a crosswind from the side at 45 knots would exceed the 40-knot limit for off-axis directions and would not be allowed.

The other options don’t match these established values, so they aren’t the correct limits for high wind start/rotor engagement.