The Water Vapour Resistant WVR Aero-bag has been designed and developed to enable the Makila Engines installed on the Airbus SA330 Puma, AS332/ AS562 Super Puma, EC225/ H225 Super Puma and Denel Aviation Rooivalk attack helicopter aircraft to be stored and preserved against the environment for indefinite periods of time whilst mounted onto a storage/ transport support stand.