What method should be used for offloading the aircraft?

The correct answer emphasizes the importance of coordination and safety in helicopter operations. Offloading the aircraft should occur only when instructed by the aircrew and ideally on a downslope. This method ensures that the crew can maintain control over the situation and that the offloading process is executed safely and efficiently.

By waiting for the crew's instruction, which takes into account current operational conditions and ensures that the helicopter is securely landed, the safety of personnel is maximized. Additionally, using a downslope for offloading helps in preventing potential hazards such as accidental roll or instability during the unloading process, which can occur on uneven terrain or an upslope. This careful approach balances operational effectiveness with the safety of both the personnel unloading the aircraft and the aircraft itself.