In which direction does the M149 Water Trailer fly during sling load?

In which direction does the M149 Water Trailer fly during sling load?

• A. Forward
• B. Backward
• C. Upward
• D. Sideways

Answer: (B)

When a load is carried under a helicopter, its motion is governed by the combination of gravity, the tension in the sling, and the air around the payload. The M149 water trailer is relatively large and creates significant aerodynamic drag. In forward flight, the rotor wash and the forward relative wind push the suspended trailer to align behind the aircraft. The sling keeps it connected, so that drag and the line angle pull the trailer to trail toward the helicopter’s tail. So, from the helicopter’s point of view, the trailer moves backward along with the rotor wash and the vehicle’s forward motion rather than straight up, forward, or off to the side.

When a load is carried under a helicopter, its motion is governed by the combination of gravity, the tension in the sling, and the air around the payload. The M149 water trailer is relatively large and creates significant aerodynamic drag. In forward flight, the rotor wash and the forward relative wind push the suspended trailer to align behind the aircraft. The sling keeps it connected, so that drag and the line angle pull the trailer to trail toward the helicopter’s tail. So, from the helicopter’s point of view, the trailer moves backward along with the rotor wash and the vehicle’s forward motion rather than straight up, forward, or off to the side.