What safety measure should be followed during the use of the MHU-226 trailer?

The choice of ensuring that the load is properly positioned and secured is crucial when using the MHU-226 trailer, as it directly pertains to the safety and stability of transporting munitions. A well-secured load minimizes the risk of shifting during transport, which can lead to accidents or even create hazardous situations if the munitions were to become dislodged. Ensuring proper weight distribution also helps maintain control of the trailer, preventing it from becoming unbalanced or difficult to maneuver.

While other safety measures, like adhering to speed limits, might seem prudent, they do not address the specific risks associated with improper loading. Similarly, while it's essential that the trailer might need to be empty for certain operations, the act of securing the load is fundamentally about ensuring safety regardless of whether the trailer is loaded or unloaded. Additionally, the prevention of lighting during transport applies to precautions against sparking in certain conditions but does not affect the immediate stability of the trailer under load.

Thus, focusing on the correct positioning and securing of loads is a primary safety measure that keeps both operators and equipment safe during the operation of the MHU-226 trailer.